Honda Cbr150

[visions]

JEEZ guys pimp your ride ............... Chrome wheels on a Cbr.... are you serious.

Haha..yes totaly agree...in my case I was looking at black chrome...actuallly black.... but a very deep gloss look that goes with the rest of the colour scheme Im going to do...

[robinhill]

Apart from a big bike I've also got a CBR150 which I used for VISA runs and general running around, etc. I fitted a 120 DURO Racing tyre to the rear - rubber seems to be pretty good - got it from Aphisit's shop in Hat Yai. Also got him to fit a gas/oil shock to the rear (the little gas reservoir resides under the seat in the cubby hole) and it makes a big difference on bumpy roads and cornering speed. Also got him to deliver an X-speed exhaust to my place in Koh Samui, which I fitted, and it made a slight improvement to the power, even though it's still a blocking type and not full race.

- These mods look good, improved the bike's handling and performance and all worked well with no problems.

Unfortunately I decided to try and get a little more power and speed out of it and got a Thai mechanic who does scooter drag bikes to do some mods on it... promises, promises, promises at every stage of the mods, assuring me 110% that he knew what he was doing and claiming that the next mod would get it working perfectly led to me spending about another 20,000 baht. And guess what,.... it now doesn't run properly and will not even start at the moment.

In case you're wondering what mods I did...

- Replaced the OHC with race version (to open valves more).

- Changed the carb to one which they use in the drag racing scooters

- Changed the ECU thing (which times the sparking I believe) for a race version which also releases rev limiter.

- Increased the capacity to 200cc.

- Got a S/Steel race exhaust (which is noisy) to help expel the gases (I also have the original pipe plus an X-Speed pipe, which is still a blocking type, but performs slightly better than the original and is not too noisy)

- Also got an electronic LED revs display, which doesn't work so well.

- Also got another voltage stabiliser thing which links to the battery.

I think that the problem resides in the engine timing in relation to the new OHC, because the engine works fine up to 6000rpm, then chokes from 6000rpm to 9000rpm, after which it takes off with quite a bit more power than before, but one has to be careful not to over-rev the engine too far otherwise the strain could be too much on the remaining standard parts of the bike which are manufactured for the power of the standard 150cc.

I don't know whether to re-fit the original cam, or spend yet more money on an expensive computer customizable ECU so that I can alter the timing to suit the racing cam.

I wonder if anyone recognizes these symptoms and can help me sort it out 'coz I miss riding the little thing.

Thanks.

[thaicbr]

Sounds more like carb tuning. same thing happened when i did some rejetting on my old one. Also thats how the drag bikes work so most Thai mechanics (still dont like putting those two words together)

[dave_boo]

Apart from a big bike I've also got a CBR150 which I used for VISA runs and general running around, etc. I fitted a 120 DURO Racing tyre to the rear - rubber seems to be pretty good - got it from Aphisit's shop in Hat Yai. Also got him to fit a gas/oil shock to the rear (the little gas reservoir resides under the seat in the cubby hole) and it makes a big difference on bumpy roads and cornering speed. Also got him to deliver an X-speed exhaust to my place in Koh Samui, which I fitted, and it made a slight improvement to the power, even though it's still a blocking type and not full race.

- These mods look good, improved the bike's handling and performance and all worked well with no problems.

Unfortunately I decided to try and get a little more power and speed out of it and got a Thai mechanic who does scooter drag bikes to do some mods on it... promises, promises, promises at every stage of the mods, assuring me 110% that he knew what he was doing and claiming that the next mod would get it working perfectly led to me spending about another 20,000 baht. And guess what,.... it now doesn't run properly and will not even start at the moment.

Somchai strikes again!!!

In case you're wondering what mods I did...

- Replaced the OHC with race version (to open valves more).

- Changed the carb to one which they use in the drag racing scooters

What size? Is it undersized for the other upgrades? Oversized? To put it in perspective; the NSR 150 used a 28mm carb from factory. Now since it's a 2 stroke, it had to feed fuel every other stroke instead of every fourth. If Honda decided that the 28mm carb was good enough (and it's a popular mod for the CBR 150), why would you want to go much bigger than that?

- Changed the ECU thing (which times the sparking I believe) for a race version which also releases rev limiter.

And that's all most of them do...remove the limiter.

- Increased the capacity to 200cc.

- Got a S/Steel race exhaust (which is noisy) to help expel the gases (I also have the original pipe plus an X-Speed pipe, which is still a blocking type, but performs slightly better than the original and is not too noisy)

- Also got an electronic LED revs display, which doesn't work so well.

- Also got another voltage stabiliser thing which links to the battery.

I think that the problem resides in the engine timing in relation to the new OHC, because the engine works fine up to 6000rpm, then chokes from 6000rpm to 9000rpm, after which it takes off with quite a bit more power than before, but one has to be careful not to over-rev the engine too far otherwise the strain could be too much on the remaining standard parts of the bike which are manufactured for the power of the standard 150cc.

That's more like jetting. He obviously doesn't know what he's doing in that regard. While such performance is all fine and dandy for a bike that is intended to start and idle at a line with a launch near redline, it sucks for a street bike.

I don't know whether to re-fit the original cam, or spend yet more money on an expensive computer customizable ECU so that I can alter the timing to suit the racing cam.

Timing is the least of the problems. Sort out the carb.

I wonder if anyone recognizes these symptoms and can help me sort it out 'coz I miss riding the little thing.

Thanks.

[dave_boo]

As a side note, it's most likely that you need to shim your main jet. If you're happy with performance below 6000 RPM, leave the low speed jet alone. Sounds to me like it's not opening enough when it is taking over the duties....

[thaicbr]

Dave did you mean shim the needle.

[dave_boo]

Dave did you mean shim the needle.

Definitely....good catch (for those who aren't in the know, you'd drill out the main jet--not shim it which is what you'd do to the jet needle).

Here's a pretty good link for those who want to learn about carbs.

(a sneak picture from the gentleman's website)

[robinhill]

Thanks for your comments so far.

The carburetor is one which they use for the drag scooters when they bore them out to 200cc - 250cc.... cost about 2,500 baht or so. This was fitted after I had the new OHC which affects the valve lifting, because the engine was already choking between 6000 and 9000 rpm, and the guy said that a new carb would definitely fix the problem.

If the problem was his bank account, then I'm sure that it helped, but it still didn't stop my bike from choking.

Forgot to mention that I also had a new race throttle grip and cable fitted too for smoother action.

And here's a laugh... the last time I was trying to get it started the battery was running out of juice, so a couple of "helpful" Thai guys offered to help push and instead of pushing on the metal rack at the back (which is fastened on securely and takes my Givi box which wasn't on at the time), they pushed on the rear fairing and broke it! Not only this, they also managed to loosen the rear seat, which dropped off somewhere on route and was never found again. I've replaced the rear seat (at a cost of around 600 baht or so I think) but have yet to fix the fairing (one piece of plastic dropped off and is missing so I can't glue it back together).

Before I started fiddling it was such a reliable little bike....

[songoku777]

That is bad! B300 is not even gonna buy a new mirror! Songoku777, what type of Pirelli tyre; the Sports Demon?

Yup its the sport demon. Theres a city demon on my other bike (but its a v cruiser) ..it's fitment looks very nice also.

Apart from a big bike I've also got a CBR150 which I used for VISA runs and general running around, etc. I fitted a 120 DURO Racing tyre to the rear - rubber seems to be pretty good - got it from Aphisit's shop in Hat Yai. Also got him to fit a gas/oil shock to the rear (the little gas reservoir resides under the seat in the cubby hole) and it makes a big difference on bumpy roads and cornering speed. Also got him to deliver an X-speed exhaust to my place in Koh Samui, which I fitted, and it made a slight improvement to the power, even though it's still a blocking type and not full race.

- These mods look good, improved the bike's handling and performance and all worked well with no problems.

Unfortunately I decided to try and get a little more power and speed out of it and got a Thai mechanic who does scooter drag bikes to do some mods on it... promises, promises, promises at every stage of the mods, assuring me 110% that he knew what he was doing and claiming that the next mod would get it working perfectly led to me spending about another 20,000 baht. And guess what,.... it now doesn't run properly and will not even start at the moment.

In case you're wondering what mods I did...

- Replaced the OHC with race version (to open valves more).

- Changed the carb to one which they use in the drag racing scooters

- Changed the ECU thing (which times the sparking I believe) for a race version which also releases rev limiter.

- Increased the capacity to 200cc.

- Got a S/Steel race exhaust (which is noisy) to help expel the gases (I also have the original pipe plus an X-Speed pipe, which is still a blocking type, but performs slightly better than the original and is not too noisy)

- Also got an electronic LED revs display, which doesn't work so well.

- Also got another voltage stabiliser thing which links to the battery.

I think that the problem resides in the engine timing in relation to the new OHC, because the engine works fine up to 6000rpm, then chokes from 6000rpm to 9000rpm, after which it takes off with quite a bit more power than before, but one has to be careful not to over-rev the engine too far otherwise the strain could be too much on the remaining standard parts of the bike which are manufactured for the power of the standard 150cc.

I don't know whether to re-fit the original cam, or spend yet more money on an expensive computer customizable ECU so that I can alter the timing to suit the racing cam.

I wonder if anyone recognizes these symptoms and can help me sort it out 'coz I miss riding the little thing.

Thanks.

On my other bike (which is a 16v GPZ), the hard starting was caused by some of the valves incorrectly gapped.. when the engine was hot, there was no problem starting.. but once it cooled down, it literally has to be cranked long enough to reach a certain temperature for it to start (with a battery charger already connected to the battery) :/

Thanks for your comments so far.

The carburetor is one which they use for the drag scooters when they bore them out to 200cc - 250cc.... cost about 2,500 baht or so. This was fitted after I had the new OHC which affects the valve lifting, because the engine was already choking between 6000 and 9000 rpm, and the guy said that a new carb would definitely fix the problem.

If the problem was his bank account, then I'm sure that it helped, but it still didn't stop my bike from choking.

Forgot to mention that I also had a new race throttle grip and cable fitted too for smoother action.

And here's a laugh... the last time I was trying to get it started the battery was running out of juice, so a couple of "helpful" Thai guys offered to help push and instead of pushing on the metal rack at the back (which is fastened on securely and takes my Givi box which wasn't on at the time), they pushed on the rear fairing and broke it! Not only this, they also managed to loosen the rear seat, which dropped off somewhere on route and was never found again. I've replaced the rear seat (at a cost of around 600 baht or so I think) but have yet to fix the fairing (one piece of plastic dropped off and is missing so I can't glue it back together).

Before I started fiddling it was such a reliable little bike....

Initially, i thought it was a carb issue as well. -it could still be tho. I think at this point it would be best if you changed something you never did yet -the mechanic

Good luck on your bike! ..these are one of the many things that motivate us to get up everyday & keep the optimism up

[T_Dog]

Was eating at a Mexican restaurant tonight when there was a ruckus at the front window. The waitress called me over to show my beloved and (up to now undinged) bike laying on its side in the headlights of a car with the driver, an old lady talking on her cell phone. A few of the customers saw her hit my bike, push it forward, and then saw it fall as she backed up. So I go out there in the rain and she denies hitting it! She spoke good English, but once she knew there were witnesses, she switched to Thai. Haven't had much of a chance to look at it with the rain, but it looks like the left mirror and the clutch handle took the brunt of it. Hopefully no internal injuries. I have her phone number, and she gave me 300 baht at the end. Arggghhhhh.

Well, I feel sorry for you guys that don't have a good mechanic to work on your bike. I dropped my bike off to get the clutch handle and mirror fixed, and the guy that works on my bike found a bent handlebar, a sticking throttle (yeah, it had felt a bit like a cruise control throttle), and a defective cam chain tensioner. I didn't believe his story about the tensioner until I let him replace it.... A high pitch rattling noise I had gotten used to is completely gone. He even replaced the bar end caps and the grips, so all that looks brand new. The clutch and throttle pressures are about a third of what they used to be, so the bike feels more responsive and faster.

So..... 1300 baht to get all the fixed, with the old lady funding 300. Hmmm.... Probably not worth the effort to go after more money so tomorrow morning..... time to ride to Chiang Dao!

[phobic]

Was eating at a Mexican restaurant tonight when there was a ruckus at the front window. The waitress called me over to show my beloved and (up to now undinged) bike laying on its side in the headlights of a car with the driver, an old lady talking on her cell phone. A few of the customers saw her hit my bike, push it forward, and then saw it fall as she backed up. So I go out there in the rain and she denies hitting it! She spoke good English, but once she knew there were witnesses, she switched to Thai. Haven't had much of a chance to look at it with the rain, but it looks like the left mirror and the clutch handle took the brunt of it. Hopefully no internal injuries. I have her phone number, and she gave me 300 baht at the end. Arggghhhhh.

Well, I feel sorry for you guys that don't have a good mechanic to work on your bike. I dropped my bike off to get the clutch handle and mirror fixed, and the guy that works on my bike found a bent handlebar, a sticking throttle (yeah, it had felt a bit like a cruise control throttle), and a defective cam chain tensioner. I didn't believe his story about the tensioner until I let him replace it.... A high pitch rattling noise I had gotten used to is completely gone. He even replaced the bar end caps and the grips, so all that looks brand new. The clutch and throttle pressures are about a third of what they used to be, so the bike feels more responsive and faster.

So..... 1300 baht to get all the fixed, with the old lady funding 300. Hmmm.... Probably not worth the effort to go after more money so tomorrow morning..... time to ride to Chiang Dao!

Mind if i ask where this mech is located? Im guessing somewhere north?

thx

[T_Dog]

Yeah, he is in Chiang Mai at one of the Honda dealerships here. Factory trained and is one of those guys that goes out of his way to do a good job. My battery died once and he even shot across town with a new one for me.

Edited August 1, 2009 by T_Dog

[phobic]

Wish i had one of those close by, to bad the mech's here are workshy to say at least hehe.

[PeaceBlondie]

I now have a local guy 33 meters from my door, who repaired my 2oo8 CBR when I crashed it.Before that for 5 years I relied on the big dealership which T Dog may use. Maybe it helps that neither of us ever modifies our stock bike much.

[phobic]

You certain its not 30m to him? or you used the GPS to measure? :D

[songoku777]

Well, I feel sorry for you guys that don't have a good mechanic to work on your bike. I dropped my bike off to get the clutch handle and mirror fixed, and the guy that works on my bike found a bent handlebar, a sticking throttle (yeah, it had felt a bit like a cruise control throttle), and a defective cam chain tensioner. I didn't believe his story about the tensioner until I let him replace it.... A high pitch rattling noise I had gotten used to is completely gone. He even replaced the bar end caps and the grips, so all that looks brand new. The clutch and throttle pressures are about a third of what they used to be, so the bike feels more responsive and faster.

So..... 1300 baht to get all the fixed, with the old lady funding 300. Hmmm.... Probably not worth the effort to go after more money so tomorrow morning..... time to ride to Chiang Dao!

1.3k is about 1.6k from where i come from. Not bad! Btw., how old (or how much KM you got on there) before you had the tensioner replaced? -I suppose the timing chain is still intact?

I now have a local guy 33 meters from my door, who repaired my 2oo8 CBR when I crashed it.Before that for 5 years I relied on the big dealership which T Dog may use. Maybe it helps that neither of us ever modifies our stock bike much.

Same here. I always reminded myself -since it's so tempting to experiment -if it ain't broke, dont touch it

[jbeck]

Yeah, he is in Chiang Mai at one of the Honda dealerships here. Factory trained and is one of those guys that goes out of his way to do a good job. My battery died once and he even shot across town with a new one for me.

If anyone is interested - at the big honda dealer by the airport plaza a mechanic named 'ME' has given me awesome, inexpensive help, fitting an entire race setup to my airblade (cylinder, piston, cam, cdi, carb, pipe), for 280 baht labor! (I tipped him +500) it was there for a week - there were no instructions and he had to troubleshoot several problems - by calling ASEAN MOTO (more than once) in BKK who sold me the kit.

I doubt the same amount of work would have cost any less on chiang moi rd (from my own experience), but this guy is really good. He can speak enuf english to explain and understand about bikes anyway.

jeff

[T_Dog]

Songoku777... If the original mileage is correct, I would guess about 22,000 km. The tensioner does bind up pretty inconsistently so it is indeed messed up inside. I asked about the cam chain, and the mechanic said it and the tensioning shoes should be okay. Here is a pic of the old parts.....

Great day for a ride today, but I will not get 7000 km out of the rear Pilot Sporty tire. Super tires, but the softness that makes them work so well doesn't make for a long life tire. I'll take the life hit to get the performance though.

[PeaceBlondie]

My 2003 CBR150 cam chain got a death rattle around 40,000 km and the Thais knew what it was and replaced it. T Dog, I'm going to check on the guy on Mahidol Road that sells those Michelins.

[In the jungle]

In part inspired by your enthusiam here I bought a new CBR 150 about three weeks ago.

I have been riding bikes for well over thirty years and I think it is an excellent bike.

I plan on wringing some more performance out of the new toy. As a first step I thought it would be useful to get some objective data on performance in essentially stock form.

If you do not like technical stuff my advice is jump to the next post right now.

I have a device called a Dynojet Wideband Commander which measures air/fuel (a/f) ratio. I am confident that it gives consistent and repeatable results. I have used it for years to do ECU tuning on racecars both on dynos and on track. It is a US$500 piece of kit and I certainly did not buy it just to play with my CBR.

The lambda sensor is installed in a welded boss just in front of the silencer on the CBR. That is the only practical position because of the size of the sensor which is intended primarily for cars. Because the sensor is downstream from the catalyst I have removed it and the front pipe is now a stepped header with two diameter increases prior to the silenceer. Externally the front pipe looks stock apart from the lambda sensor which is replaced by a blanking plug when the sensor is not in use. It would have been a lot easier and cheaper to buy an after-market front pipe but they do not have the dimensions I want.

The Dynojet wideband commander is capable of datalogging air fuel ratio against rpm and two other parameters but I have not had time to set all that up. I will do that in a couple of weeks time. With the race cars I have been running you have to use datalogging because the cars rip through the gears so fast you cannot follow what is happening by looking at an a/f meter.

With the CBR things happen a bit slower so right now I have the Dynojet analogue air/fuel ratio meter cable tied to the left hand mirror stem which is about six inches from my nose when I am in chin on tank mode. The a/f meter will be removed once I get things as I want them hence the temporary install.

Air/fuel ratio results:

The data below is based on 500 km of testing. I do not think the exhaust mods will have made much difference to performance so the following information is, I think, pretty reliable information on a/f ratio for a stock CBR running in an ambient temperature of around 30 degrees. Everything other than the exhaust front pipe is stock.

1. At 75% to Wide Open Throttle (WOT) the air fuel mixture is pretty close to what I think is right at the top end of the rpm range.. The air fuel ratio varies between about 12.7:1 and 13.0 to 1.

2. But as you get near to 11,000 rpm plus at WOT the mixture gets progressively richer. The a/f ratio there is around 11.7 to 11.8:1.

With a programmable fuel injection system you could easily correct that by going tap, tap, tap on a laptop. With a carburettor things are not so simple.

By making the mixture leaner right at the top end I think the bike would make more power and run faster. But not by a huge amount due to aerodynamics and the stock rpm limit. I am not suggesting a simple main jet swap as I think that would make the bike run too lean on WOT at lower rpm.

At the moment the bike is maxing out at about 11,200 rpm in sixth which, if my gearing calcs. are correct is about 144 kph. Taking off the mirrors would probably get you close to the rpm limiter but there is no way I am going to do that. On Thai roads I want all the safety aids I can get!

3. When you are trundling around town I had assumed that pick up, when you roll on the throttle, was limited because it's a tiddly little 150 engine.

But now I have the lambda sensor on the bike the a/f ratio shows that on a steady throttle at around 5000 rpm and 20% to 25% throttle the engine is running pretty rich at 11.0:1. When you roll on the gas it richens further to anything up to 10.0:1 depending on exactly where you are in the rpm range.

If the engine were running leaner here, say 12.5:1, I think pick up under these conditions would be much sharper and fuel consumption would improve.

My initial thoughts on air/fuel ratio:

My guess is that the stock bike would run better with a leaner needle combined with a larger main jet.

Why a larger main jet given that I said it was running rich right at the top end of the rpm range?

Because even at WOT the needle has some limited influence on a/f ratio. The larger main jet would be offset to a degree by the leaner needle. But to know for sure the only way would be to test and that can be a time consuming process swapping different needles and jets in and out.

The catch in all of this is that alternative needles, needle jets and even main jets for the standard carb are not readily available. If anyone knows better please let me know.

I have been told that common practice in Thailand is to re-drill stock main jets to different sizes but for at least a couple of reasons I do not think that is a good idea.

But before masking any changes I want to get the datalogging working so I can nail down the baseline for a stock bike some more.

With a bit of machining it would be possible to fit a throttle position sensor (TPS) to the stock carb but I probably will not do that as the likelihood is that I will change from the standard carb soon. My 'TPS' will be a bit of tape stuck to the throttle with percentages marked on it such as 20, 25, 50, 75.

[T_Dog]

Welcome to our jungle, IntheJungle, and congrats on the new bike. Many of us on the forum have a lot of motorcycle experience from the past like you, and your notes on fuel-to-air data are darn interesting. I ride up in the mountains a lot, and I figure my engine should be running leaner here at 300 meters as once you climb up, it only gets richer. My exhaust port runs a bit black, but that is the extent of my data! Your analyzer sounds pretty cool. I really don't want to make any big performance mods though as I am happy with the bike as it is. Plus in the past, when I was trying to get the last ounce of power, it usually was!

Enjoy the forum and the bike!

[dave_boo]

Welcome to our little club inthejungle.

Good info about the readings from the WBS. I've always wondered what our bikes were set up at; I've never seen the enriched condition that T_dog has mentioned, but I'm less than 100 meters above sea level...

From what I've gathered the Keihin PE 28 is a popular mod for the CBR 150; add in the fact that there's plenty of needles for it should make your job of finding the right combination extremely easy.

**edit**

Was mistaken about my elevation; google earth claims it is 153m......

Edited August 2, 2009 by dave_boo

[In the jungle]

I was thinking of the PE 28 as it is readily available and not too expensive at around THB 2100 from a Honda dealer (stock carb for an NSR 150). With the throttle, throttle cable and other necessary bits and pieces it runs to about THB 2500.

Add to that a whole bunch of needles, jets and whatever it costs to buy or fabricate the bits to nail the carb to the head and the airbox. The NSR needle is pretty sure to be way too rich for a CBR.

Given that I am using the CBR as a road bike a PE 26 might be a better choice on the basis that slide carbs generally flow more air than CV carbs but they do not seem to be so readily available here. Whereas, by contrast, I have literally seen PE 28s by the box load on a market stall at around THB 1800. No idea whether they are genuine. I'll pay the extra THB 300 to Mr Honda.

All my testing was done around sea level.

I'll probably do a run up to Chiang Mai in a couple of weeks. Where I live most of the roads tend to be straight line, 90 degree turn, straight line, 90 degree turn etc. After 1000 km plus I still don't really know how the CBR performs in corners.

[jbeck]

I was thinking of the PE 28 as it is readily available and not too expensive at around THB 2100 from a Honda dealer (stock carb for an NSR 150). With the throttle, throttle cable and other necessary bits and pieces it runs to about THB 2500.

Add to that a whole bunch of needles, jets and whatever it costs to buy or fabricate the bits to nail the carb to the head and the airbox. The NSR needle is pretty sure to be way too rich for a CBR.

Given that I am using the CBR as a road bike a PE 26 might be a better choice on the basis that slide carbs generally flow more air than CV carbs but they do not seem to be so readily available here. Whereas, by contrast, I have literally seen PE 28s by the box load on a market stall at around THB 1800. No idea whether they are genuine. I'll pay the extra THB 300 to Mr Honda.

All my testing was done around sea level.

I'll probably do a run up to Chiang Mai in a couple of weeks. Where I live most of the roads tend to be straight line, 90 degree turn, straight line, 90 degree turn etc. After 1000 km plus I still don't really know how the CBR performs in corners.

I am using a genuine PE28 on my airblade (smaller engine and only 2 valves) and it works excellent, so I do not think a PE26 would be a wise choice for the CBR.

If you would like to do a ride up doi suthep PM me.

Jeff

Edited August 3, 2009 by jbeck

[songoku777]

Songoku777... If the original mileage is correct, I would guess about 22,000 km. The tensioner does bind up pretty inconsistently so it is indeed messed up inside. I asked about the cam chain, and the mechanic said it and the tensioning shoes should be okay. Here is a pic of the old parts.....

Great day for a ride today, but I will not get 7000 km out of the rear Pilot Sporty tire. Super tires, but the softness that makes them work so well doesn't make for a long life tire. I'll take the life hit to get the performance though.

I think it's a good idea to ask the mechanic the 'old parts' that were replaced.. just to make sure it was really replaced ^^

22k still seems quite young for an engine. Maybe, it depends on the way the engine was used. For racing, i think its life will be much shorter. Most local CBR150s here get some carb problems @ around 20-25k on the clock.. a little cleaning (some change to PE28 carbs) during that time. Mine still has about 7k to go.. and i'll definitely be sharing findings about mine.

Congrats on your purchase of a CBR150 In the jungle. That a/f sensor sounds interesting!!

It may sound odd, but a primitive way i always used to tune engines was partly from the smell of the exhaust (not too much since it might get you high).

What's interesting about your sensor is it progressively tells the a/f ratio. That's one worthwhile equipment and definitely worth the cost.

Thats right dave_boo. From where i come from, PE28 is also the carb of choice -not only for CBR150s but for some other bikes that have the same (or around the same) displacement. I've yet to fit mine with one -as im still experimenting with it.

I.T.J. is right, these non-electronic carbs really have a trade off on either end. So tuning will vary depeding on the prupose of the bike. Mine's a killer from 0-120 since its mostly used as an urban warrior ^^ get's pretty boring on long stretches tho -besides, little motorcycles cant enter the freeway here. You have to be atleast 400cc to 'enjoy' :/

Edited August 3, 2009 by songoku777

[dave_boo]

I forget the exact sized carb that the CBR uses stock, but if you're going to go apeshit with upgrades I do think that the PE28 is about as good as it gets. Perhaps the 26 would work fine also, but the 28 gives you some room to play with.

I've also heard about people talking about using the PWK28...not sure how well that would work. Seems to be a popular mod for the CRF-150, but the PWK definitely is softened in the centre of the powerband for motocross work.

One thing to note for all those going with the PE28; the pull is much larger than the stock CBR 150 carb. You'll either need a "short pull" throttle or a throttle from a NSR 150....otherwise you won't be able to open the carb all the way up.

inthejungle; it handles quite nicely for such a small bike. Very tossable.

jbeck; is that airblade set up for only drag racing? What type of jets/needles you got in there?

songoku777; there's a better way to check than huffing exhaust fumes....look at the condition of your spark-plug. White too lean, sooty too rich. Nice brown a-ok (mostly...inthejungle has the tool you actually need).

[thaicbr]

Hi guys. Here's another Cbr exhaust and big bore website. looks cheap as well. www.grim-dbs.com enjoy. Allan

PS Dave they also have a nice looking exhaust for the Ninja250 only 7,000b complete.

Edited August 4, 2009 by thaicbr

[songoku777]

Different aftermarket pipes for the CBR ^^

Btw does anyone know 'how' these help increase power (aside from the unrestricted muffler itself) since all of the pipes above seem to have the same little size down-pipes like the stock?

[thaicbr]

songoku. they are a lot larger internal diameter than the stock and make a big increase in ride ability and midrange. also they do not have the restricta part that is in the end.

[jbeck]

Boolander: You asked: is that airblade set up for only drag racing? What type of jets/needles you got in there?

I got a complete kit (supposedly they supply road racing teams) from asean moto: cyl, piston, head, cam, CDI, PE28 carb, Intake manifold, Endurance stainless steel pipe. Also the head has been ported.

Too excited and forgot to check the jetting, but I think the main is a 108.

The airblade is used daily for normal 'fun' use and to my amazement runs perfectly with the jetting 'as is' exactly as asean moto said it would. From idle to about 125 without any fuss and there was more to be had, but I have only about 100km on the new engine. It will be for sale soon to finance the next project. It accelerates from 0-100 in about the same time it used to take from 0-55.

Sorry, this is a CBR thread!

Jeff