Carburettor Leaking On New Bike

[geoffphuket]

The dealer delivered my new Gusto Rumba motorbike Saturday afternoon. After putting some petrol in the tank (it was empty), I noticed a strong smell of fumes while the engine is running. After a closer inspection I discovered that petrol is running out of a small hose at the bottom of one of the Mikuni carburettors - the other carburettor seems to have this pipe missing?

Obviously We're contacting them to pick the machine back up, but I'd like to hear from one of our experts as to what the problem might be, and if whether there should be a hose on each carburettor ? I'm no expert in this field

[Crossy]

The hose is the overflow from the float chamber, if fuel is coming out then the float level is incorrect or the float is stuck (likely if the tank has been empty for a while), try a sharp tap to the float chamber, it may free it.

Obviously both carbs will have an overflow although they may exit into a single tube (not sure about your exact vehicle).

[dave_boo]

I don't want to seem like a complete sh!thead about it, but the problem is the bike you bought (more specifically the construction of it). Sometimes it is good to have herd mentality. Looking at the picture, you can see that the nearest brass nipple is broken off. The fact that they didn't use a hose clap on the other one is also disturbing. Good luck with getting your bike up to an acceptable standard.

[geoffphuket]

The hose is the overflow from the float chamber, if fuel is coming out then the float level is incorrect or the float is stuck (likely if the tank has been empty for a while), try a sharp tap to the float chamber, it may free it.

Obviously both carbs will have an overflow although they may exit into a single tube (not sure about your exact vehicle).

Cheers Crossy. That's what I thought, although it looks as if the missing hose and nipple on the second carb' has been snapped off.

[madjbs]

the float is stuck (likely if the tank has been empty for a while)

Yep that will be it, do as crossy said and give it a few knocks.

[Crossy]

........it looks as if the missing hose and nipple on the second carb' has been snapped off.

It does indeed, if this is a brand new machine it's time to take it back and get it fixed.

[geoffphuket]

the float is stuck (likely if the tank has been empty for a while)

Yep that will be it, do as crossy said and give it a few knocks.

If it cured the problem, I'm still unsure about the second carb. A friend suggested that their maybe an internal fuel line between the two, and that two hoses are unnecessary. I guess the only way to know for sure, is to compare with another bike.

[geoffphuket]

........it looks as if the missing hose and nipple on the second carb' has been snapped off.

It does indeed, if this is a brand new machine it's time to take it back and get it fixed.

Yep, brand new. I don't think I'll tamper, they can collect it tomorrow.

Cheers for they replies lads

[goldfish]

I don't want to seem like a complete sh!thead about it, but the problem is the bike you bought (more specifically the construction of it). Sometimes it is good to have herd mentality. Looking at the picture, you can see that the nearest brass nipple is broken off. The fact that they didn't use a hose clap on the other one is also disturbing. Good luck with getting your bike up to an acceptable standard.

A tad harsh but amusing and accurate, tho I'm not sure you'd usually get a clamp on an overflow pipe. Crossy' advice is correct, of course, although it could also be a blocked fuel shut-off valve. Maybe a bit of rust from your new tank made it's way down the fuel line. If they can deliver a bike in this condition anything is possible

[Gary A]

Any dealer that would deliver a new bike without fuel in the tank and without a ride test would be best avoided. I hope the bike turns out better than what I perceive the dealer to be.

[PeaceBlondie]

Gusto Rumba sounds like a Mexican dance or a Jamaican drink. Who makes them, The Haile Selassie Memorial Ganja Motor Co.?

[HDRIDER]

HI

You get what you pay for

[geoffphuket]

Gusto Rumba sounds like a Mexican dance or a Jamaican drink. Who makes them, The Haile Selassie Memorial Ganja Motor Co.?

See the other thread: http://www.thaivisa.com/forum/index.php?showtopic=172256

[geoffphuket]

I don't want to seem like a complete sh!thead about it, but the problem is the bike you bought (more specifically the construction of it). Sometimes it is good to have herd mentality. Looking at the picture, you can see that the nearest brass nipple is broken off. The fact that they didn't use a hose clap on the other one is also disturbing. Good luck with getting your bike up to an acceptable standard.

A tad harsh but amusing and accurate, tho I'm not sure you'd usually get a clamp on an overflow pipe. Crossy' advice is correct, of course, although it could also be a blocked fuel shut-off valve. Maybe a bit of rust from your new tank made it's way down the fuel line. If they can deliver a bike in this condition anything is possible

I notice there's only petrol running out the hose while the engine's running...would that be a stuck float, or the shut off valve....or either ?

[technologybytes]

Hi Geoff,

This bike has a vacum operated fuel tap system so the fuel is shut off when the engine is not running, that will be why the fuel only comes through when it's running.

It is disturbing that the dealer did not run the bike prior to delivery, when I bought mine I insisted that they show me it running before I paid, the reason was simply that the demo machine did not run very well, but I had seen one at a smaller dealer that run smooth as silk, but I wanted to buy from the bigger dealer (JRD Scooter Arena).

The quality of these bikes is not bad, it's the monkeys that assemble them that cause the problems. The Hondas and other Jap bikes are assembled at the factory and delivered on a truck, chinese bikes are built up from a crate bu Thai's. I'm sure that once they have built a lot of them they will get better!

I have two Chinese bikes now, and they are both fine. I know that lot's of people are biased against Chinese stuff, but let's be clear that it's not the hardware thats the fault.

That picture of Geoff's carbs may not make it clear, but they are Mikuni carbs and no different to a Jap bike, it's the dealer that's at fault here not the bike per se.

JRD Scooter Arena have some work to do for sure with their customer service and their quality control over pre-delivery-inspections, but at least they don't look like they are likely to go bust and they should still be around for the duration of the the 3 year warranty.

Mine has done 1590 km and the only real issues were the exhaust flange being put on wrong, a loose headlight assembly, and a few nuts and bolts that needed tightening.

JRD do the first "service" at 500km (unlike platinum who say 4000km!), better to allow some time for the service and watch over them as they attend to every squeak or rattle, then I'm sure it will be OK.

Any bike could have a stuck float when new, only a Thai dealer would deliver the bike without checking it...

I don't want to seem like a complete sh!thead about it, but the problem is the bike you bought (more specifically the construction of it). Sometimes it is good to have herd mentality. Looking at the picture, you can see that the nearest brass nipple is broken off. The fact that they didn't use a hose clap on the other one is also disturbing. Good luck with getting your bike up to an acceptable standard.

A tad harsh but amusing and accurate, tho I'm not sure you'd usually get a clamp on an overflow pipe. Crossy' advice is correct, of course, although it could also be a blocked fuel shut-off valve. Maybe a bit of rust from your new tank made it's way down the fuel line. If they can deliver a bike in this condition anything is possible

I notice there's only petrol running out the hose while the engine's running...would that be a stuck float, or the shut off valve....or either ?

[Kimera]

I don't want to seem like a complete sh!thead about it, but the problem is the bike you bought (more specifically the construction of it). Sometimes it is good to have herd mentality. Looking at the picture, you can see that the nearest brass nipple is broken off. The fact that they didn't use a hose clap on the other one is also disturbing. Good luck with getting your bike up to an acceptable standard.

A tad harsh but amusing and accurate, tho I'm not sure you'd usually get a clamp on an overflow pipe. Crossy' advice is correct, of course, although it could also be a blocked fuel shut-off valve. Maybe a bit of rust from your new tank made it's way down the fuel line. If they can deliver a bike in this condition anything is possible

I notice there's only petrol running out the hose while the engine's running...would that be a stuck float, or the shut off valve....or either ?

Well the float controls the inlet valve to the float chamber, the leaking fuel can be the result of two things, incorrect float adjustment or leaking / sticking valve !!!!!!!!!!!!! where is the shut off valve ?

[PeaceBlondie]

Even well designed and well assembled cars and bikes can have design defects and assembly defects. I once bought a new Suzuki 850 in which the mechanic failed to put grease in the rear drive gear, and it self-destructed that night on the freeway at 100 kph! However, the only vehicles I knew that were worth putting together after delivery (because the factory did not assemble it pioperly) were the early Lotuses - or would they have been Loti? Chinese bikes are not Lotuses.

geoff, I hope this Chinese bike is what you wanted, and that you enjoy it, even if it sounds like a gutsy rhumba.

[geoffphuket]

Even well designed and well assembled cars and bikes can have design defects and assembly defects. I once bought a new Suzuki 850 in which the mechanic failed to put grease in the rear drive gear, and it self-destructed that night on the freeway at 100 kph! However, the only vehicles I knew that were worth putting together after delivery (because the factory did not assemble it pioperly) were the early Lotuses - or would they have been Loti? Chinese bikes are not Lotuses.

geoff, I hope this Chinese bike is what you wanted, and that you enjoy it, even if it sounds like a gutsy rhumba.

Thanks for that. The bike itself is actually quite well assembled - maybe not to BMW standards, but impressive considering the price. if you take off the value of the free scooter they threw in, then the Rumba works out at only 37,000 Baht. Quite Astonishing !

Didn't Lotus stand for 'Lots Of Trouble Usually Serious'

geoffphuket

I forgot to add; It can't be such a bad bike since BMW decided to make a copy called the GS650 :D

[geoffphuket]

Thanks to Technologybytes for going to the trouble of sending me a photo of his bike, I now know for sure it's broken

[bino]

That's a bummer Geoff!

I can't imagine that Mikuni shipped the carb from Japan with the nipple broken off like that. They are normally considered to be a good quality supplier.

I'll bet that whoever put your bike together dropped it on the assembly room floor. An impact like that (strong enough to break the nipple) would probably knock the float valve or other delicate internals out of whack.

[PeaceBlondie]

Thanks, geoff, for recalling what Lotus stood for back then. The joke was that they would be designing some part for a production car and when they asked founder Colin Chapman, he was too busy on the Grand Prix car.

Seriously though, the mere fact that some engine made in China or Ulaan Baatar is a "copy" of an old Honda or BMW design is no guarantee, even of good original design. It took BMW about sixty years to correct their devilish shaft drive, refusing to take hints from Austrian and Japanese who solved the problem. Likewise, back to carburetttors, BMW had a leaky gasket in the float bowl for many years, which was easily solved by replacing it with a neoprene gasket. Or so my Suzuki guy told me. I think you can still buy Ural motorcycles, complete with sidecar, based on the BMW machinery that was taken to Russia as world war two reparations, but I doubt it has modern BMW assembly standards.

[goldfish]

These photos were taken from the internet and are not of Geoff's bike

[geoffphuket]

That's a bummer Geoff!

I can't imagine that Mikuni shipped the carb from Japan with the nipple broken off like that. They are normally considered to be a good quality supplier.

I'll bet that whoever put your bike together dropped it on the assembly room floor. An impact like that (strong enough to break the nipple) would probably knock the float valve or other delicate internals out of whack.

I said exactly the same to my wife! ....they probably have to pay for what's broken.

The mechanics turned up 30 minutes after we phoned this morning with a brand new carburettor - I was impressed to be honest, considering it's a 25 minute journey. After fitting it they then had a problem with fuel coming out of both tubes. It was taken back off, dismantled, a poke here and there and refitted. STILL THE SAME! .... So much for Japanese Mikun carbs!!

The bikes now gone back to the service department and I've been promised it'll be returned later today. WE'll SEE

geoffphuket

[geoffphuket]

Gusto Rumba sounds like a Mexican dance or a Jamaican drink. Who makes them, The Haile Selassie Memorial Ganja Motor Co.?

If it (and me) lasts another ten years, I'll rename it the 'Rusty Grumbler'

Thanks to everyone for their input on this very informative thread

[HDRIDER]

That's a bummer Geoff!

I can't imagine that Mikuni shipped the carb from Japan with the nipple broken off like that. They are normally considered to be a good quality supplier.

I'll bet that whoever put your bike together dropped it on the assembly room floor. An impact like that (strong enough to break the nipple) would probably knock the float valve or other delicate internals out of whack.

I said exactly the same to my wife! ....they probably have to pay for what's broken.

The mechanics turned up 30 minutes after we phoned this morning with a brand new carburettor - I was impressed to be honest, considering it's a 25 minute journey. After fitting it they then had a problem with fuel coming out of both tubes. It was taken back off, dismantled, a poke here and there and refitted. STILL THE SAME! .... So much for Japanese Mikun carbs!!

The bikes now gone back to the service department and I've been promised it'll be returned later today. WE'll SEE

geoffphuket

Hi

The name is Mikuni, and they are some of the best on the market, i even put 2, 45m/m on my Harley , all comes down to the people there work on them and your bike, it’s very hard to find a real good mechanic here, i have one and i am happy to pay him 500 an hour to do a good job.

[Thanh-BKK]

Hi

I had the exact same problem with the one carb on mine RXZ (also a Mikuni), it suddenly started pissing petrol. The shop tried various things - new floater, new floater needle and valve - still it kept doing it, not always, but suddenly starting during riding.

I ended up getting a brand new carb (same type) and the problem was gone, still got the old carb but no idea what's wrong since all parts involved had been replaced and it still did it.

Maybe Mikuni isn't all that foolproof anymore

Best regards.....

Thanh

[geoffphuket]

That's a bummer Geoff!

I can't imagine that Mikuni shipped the carb from Japan with the nipple broken off like that. They are normally considered to be a good quality supplier.

I'll bet that whoever put your bike together dropped it on the assembly room floor. An impact like that (strong enough to break the nipple) would probably knock the float valve or other delicate internals out of whack.

I said exactly the same to my wife! ....they probably have to pay for what's broken.

The mechanics turned up 30 minutes after we phoned this morning with a brand new carburettor - I was impressed to be honest, considering it's a 25 minute journey. After fitting it they then had a problem with fuel coming out of both tubes. It was taken back off, dismantled, a poke here and there and refitted. STILL THE SAME! .... So much for Japanese Mikun carbs!!

The bikes now gone back to the service department and I've been promised it'll be returned later today. WE'll SEE

geoffphuket

Hi

The name is Mikuni, and they are some of the best on the market, i even put 2, 45m/m on my Harley , all comes down to the people there work on them and your bike, it’s very hard to find a real good mechanic here, i have one and i am happy to pay him 500 an hour to do a good job.

I profoundly apologise for missing the last i off Mikuni. I promise to never make another spelling mistake ever again.

The bike's been returned this afternoon with the carburettor problem fixed, but After they'd left I noticed someone has had an accident with the rear body panel surrounding the filler cap - it's cracked in half. Another complaint tomorrow!

[geoffphuket]

The cat's found a use for it anyway...maybe one day I'll get to ride it

[Lickey]

Float bowl drain tube yes, overflow tube, never!!!, no Mikuni or other carbs have this, go on somebody, prove me wrong!

[Thanh-BKK]

How much you pay if i DO prove you wrong??

When i come back home i'll open up my old Mikuni that's still sitting here and i'll take pics showing you how the overflow works. It's the same outlet tube, yes. But to drain the float bowl you'll have to open a screw on the botom to open a BOTTOM canal while overflow is a TOP canal, ending in the same (bottom!) outlet nipple.

Pics will follow in about an hour.

Thanh