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[james1desmond]

hey guys i have a honda cbr 150 but i know very little about bikes, so i was wondering if anyone could help me with info on the performance of the bike as when its gets to 100km an hour it feels a little unstable which from other posts seems odd, and any info on modifications that improve performance and handling would be great.

I brought the bike second hand its 2/3 years old, i changed the tyres and brake pads as both were well worn, recently i changed the chain and sprockets as it had missing teeth and was clicking.

i have been looking through forums and realise this will probably be pulled apart by people who have far too much time on their hands, but i am an English teacher not a bike mechanic so genuine help only and lets keep the sarcasm to a minimum. thanks

[crazyswede]

i have a honda cbr 150 .... when its gets to 100km an hour it feels a little unstable

What do you expect from a moped in 100kmh ?

[PeaceBlondie]

My CBR150 is stock and it's no step-thru. Stable to 140 kph. No missing teeth, and my brake pads lasted to 46K km.

The Mother of all CBR150 threads

http://www.thaivisa.com/forum/Honda-Cbr150...60#entry3354593

[troehr]

You say you do not know much about motorcycles, so it is possible there is nothing wrong with your bike. They can feel a little unstable if you are not an experienced rider when you get over 100kph. Things like wind and such have more of an effect. You just get used to it after awhile. Just remember that when you are riding that fast, bad things can happen to you faster. Spend some time getting used to the bike before you start riding it at higher speeds. Other than when I am on a good road out of town do I ever ride above 80kph. Also, if you have missing teeth on your sprockets and other damage, you might look at the frame and the wheels and make sure everything is still straight. It is possible the bike was either raced or wrecked. If you have a bent wheel or something it will make things worse the faster you go. I had to replace the wheels on my NSR when I first got it for this same reason. They were bent. The CBR is a great in town commuter bike. Enjoy it.

Tim

[Richard-BKK]

The Honda CBR150R is a motorcycle capable of 120km/h without doing much effort, if your bike doesn't go over the 100km barrier then there is something wrong mechanical.

Check and clean the (or let somebody do it) the air-filter, carburettor, spark-plug and exhaust system.

Not so long ago I met a Honda CBR150R owner who also had a problem with his bike not giving all the power, the problem was found in the throttle cable, the cable adjusters where poorly set and therefore the wrist-grip was unable to open the pulley on the carburettor 100%.

The problem of your bike feeling unstable over 100km/h could be that one of your wheels is out of balance. Did one of your tires had a flat lately? It is possible that by re-inflating the tire it did not settle correctly and creating a funny wobble (100km/h is about the speed you feel wheel balance problems).

[dave_boo]

I agree with Richard...most likely an issue with the wheels. EVERY CBR I've see has had little pieces of lead clamped onto their wheels; this is a balance that keeps the wheel spinning true. If your bike doesn't have them (and I don't see any in your picture) that'd be my guess. However this would likely evidence itself in a 'shimmy' of the wheels. Another thing to consider is the supension; if it seems to have too much play in it then that's just exacerbated at speed (F=M*A and the bike's/your weight applys more force to the suspension at higher speed). If you're of substantial weight than getting the preload (little ring thingy on rear shock) up a notch or two may help out. I'd also get a ruler out and check your rear tyre's alignment; having the same distance on both sides of the tyre<-->swingarm will prevent any drifting that you may be noticing. Another trick that is available is to have the front forks lowered in the clamps (triple trees); my brother in law did that to my CBR (and got his ears boxed).

Overall it does look like a really nice ride (laid down once on the left? I see paint missing from kickstand and looks like the shifter may have been straightened); I understand why you needed new sprockets--there's a lot of wear on the rear swingarm that gives away the fact that previous owner(s) used too short of a chain.

[james1desmond]

thanks for all the info guys, i took the bike for a service last week and they siad that firstly the clutch was to tight (now the gear transitions are smoother), they also cleaned out the carburetor and changed the oil (which i was recommend to do every 1,000 km) i checked the wheel alignment and it seems fine the mechanic didnt seem to think there was a problem there. to be honest just getting them to oil and reset the chain, change the engine oil and gears has had a major effect not so much on the speed but on the performance and rideabiltiy ( I realsie thats a made up word) of the bike.

thanks again guys

[neverdie]

Who recommened that you change the oil & clean the carby every 1000km? Something not right in that. To help you. Depending on the type of trips you do, ie: lots of short trips or trips where the motor gets up to full temprature, then if the latter of those two you should only need to change the oil in that bike every say 3 or 4 thousand kilometres (I think honda recommends 4 thousand). If its taking a long time to do that amount of kilometres, then you may want to change the oil say every 3 months.

Changing the oil without changing the oil filter isnt best practice.

Also the reason your carby gets dirty is because the air filter isnt clean. I would suggest that you also replace the air filter often as here in many parts of thailand the roadways are dusty and they get dirty quickly. When you inspect the air filter it may not appear that dirty but it only takes the smallest particles of dust to get in the carby and performance suffers. If your going to clean the carby, make sure theres a new airfilter in place, no point paying to pull that out if after the first time you start it the dirty filter just pumps unclean air back into the carby.

FINALLY, many people tend to forget valve clearances on these small 4 stroke motorcycles and just small indiscrepancies with valve clearance can effect performance significantly. If the bike is a couple of years old and has done say more than 15,000km, then I would bet the previous owner hasnt attended to valve clearance and this needs to be check and adjusted by someone competent.

Good luck and check out the sub forum that peaceblondie recommended, theres piles of info about the cbr150.

[johng]

FINALLY, many people tend to forget valve clearances on these small 4 stroke motorcycles and just small indiscrepancies with valve clearance can effect performance significantly. If the bike is a couple of years old and has done say more than 15,000km, then I would bet the previous owner hasnt attended to valve clearance and this needs to be check and adjusted by someone competent.

sorry off topic a bit but

Neverdie please can you tell me what the valve clearances should be on the Suzuki Raider 150.

[neverdie]

Mine were only done in December, from memory it was .15 on the intake valve and .25 on the exhaust.......BUT I've got a shocking memory, so if you like I will ask this Sunday when I see MR SUZUKI , as going off my memory isnt the best thing for any of us to do , I will let you know what the Suzuki workshop manual says........ive just got to remember to look this sunday

[johng]

Hi Neverdie,

I just checked in my owners manual, the Thai version for some reason doesn't have the valve clearance data

but the Filipino ( English ) version does have this info.

IN 0.10-0.20mm

EX 0.20-0.30mm

so your memory is in fact shockingly good Still would be nice to know what the workshop manual says though.

Also to adjust the valve clearance does it involve a lot of work dismantling the head etc ?

looks like its a bit of a pain to do because of the method of adjustment being shims.

Thanks for your replies.

[neverdie]

hi johng,

everybody has to get something correct eventually, even me .

okay, firstly, yes its SHIMS and it can be a little bit fiddly, you definately need a good kit of spare shims if you want to get this job accurately done, as for some reason clearance always seem to be out by odd numbers and we got mine done spot on the .15/.25.

The Raider set up is overhead cams, so the head doesnt come off, just the rocker cover and the cams themselves come out to remove and replace the shims after working out what the original clearances are. Also it is important when removing the cam shaft to mark down the correct spacing of links for the timing chain, I was going to quote that too, but cant remember, we used small zip ties to mark off the correct spacing, because theres nothing like putting it back together after lunch and getting that wrong, afternoon detonation can really spoil the day .

Its not a hard job, although i didnt tackle it on my own, I had Mr Raider working with me. It certainly made a difference to my top end speed which had been reduced, although at the same time I also put on another larger carby and jet kit, new spark plug, air filter etc and the bike was like new again......my thought was the valve clearances were the main problem.

Anyway, hope this helps, I will still check the workshop manual on Sunday, just in case Ive have messed up.

ps: I would much rather do shims on a simple motor like the raider than my other bike, CBR600, I reakon I would definately stuff that up

Edited February 25, 2010 by neverdie