Bloody Carbs!

[CockneyRick]

Any suggestions?

GSX1100f engined Slabby drag bike.

CV36 carbs with a Sigma6 kit fitted.

No1 carb was leaking, so bought a rebuild kit comprising of valve seats, valves & seals. Set the float height at 14mm approx. bench test & now No 1-2 & 4 are leaking?

I did swap valve seat seals as the ones supplied were too thick to even get them to fit in hole. Any way of testing if the fuel is getting past them perhaps? Or could the issue be elsewhere?

 

 

 

All reactions:

11

 

 

[Swiss Toni]

Gonna wheelie like a bastard with that wheelbase, Ricardo!

[Upshotknothole]

Only places I ever see fuel leaks are either float valves or the T fuel fittings between 1&2 and 3&4.

Try the old tapping on the sides of the bowls trick to free up the floats if they happen to be hung up on something? Did you mix the new valves with the old seals? Could be they don't match up close enough.

[Captain Chaos]

I think the bike is suicidal and wants to self-combust because it has an ugly paintjob.

[TonyGee]

1 hour ago, Captain Chaos said:

I think the bike is suicidal and wants to self-combust because it has an ugly paintjob.

harsh   but true 

[TonyGee]

was it a cheap Chinese kit Rick ?

[CockneyRick]

2 hours ago, Upshotknothole said:

Only places I ever see fuel leaks are either float valves or the T fuel fittings between 1&2 and 3&4.

Try the old tapping on the sides of the bowls trick to free up the floats if they happen to be hung up on something? Did you mix the new valves with the old seals? Could be they don't match up close enough.

Fuel is coming out of the pilot air jets, not leaking from anywhere else/

[CockneyRick]

2 hours ago, Captain Chaos said:

I think the bike is suicidal and wants to self-combust because it has an ugly paintjob.

Hydro dipped, not paint 

[CockneyRick]

36 minutes ago, TonyGee said:

was it a cheap Chinese kit Rick ?

Eblag from UK, quite possibly Chinese then!

[TonyGee]

3 minutes ago, CockneyRick said:

Eblag from UK, quite possibly Chinese then!

if it was the quality is hit or miss 

[TonyGee]

7 minutes ago, CockneyRick said:

Fuel is coming out of the pilot air jets, not leaking from anywhere else/

its leaking from the float valves or seats. 

[CockneyRick]

1 hour ago, TonyGee said:

its leaking from the float valves or seats. 

So the new kit is worse than the worn out ones!

[TonyGee]

14 minutes ago, CockneyRick said:

So the new kit is worse than the worn out ones!

it sounds like ????  I use tourmax stuff, its meant to be made in Japan !!!!  but never had an issue with their stuff yet.  just bought a fuel tap from them for the ET, works great (so far) 

[Upshotknothole]

1 hour ago, CockneyRick said:

Fuel is coming out of the pilot air jets, not leaking from anywhere else/

Yeah, that's the float valves. My guess is the new valves don't like the old seats.

[Captain Chaos]

7 hours ago, CockneyRick said:

Hydro dipped, not paint 

The bike doesn't know the difference

[Nick]

8 hours ago, TonyGee said:

it sounds like ????  I use tourmax stuff, its meant to be made in Japan !!!!  but never had an issue with their stuff yet.  just bought a fuel tap from them for the ET, works great (so far) 

Tony,  I had this with brand new Tourmax float valves recently - they leaked like a sieve, fuel pissing out the pilot air jets.

 

The quality control on them is way off, I think, and they are nothing on the Mikuni ones I have since fitted, which do not leak...

 

Not sure if I got fakes or if Tourmax stuff has just gone downhill in general?  If you buy direct from Mikuni, it's cheaper than buying them in a Suzuki bag.

[Dezza]

 

59 minutes ago, Nick said:

Tony,  I had this with brand new Tourmax float valves recently - they leaked like a sieve, fuel pissing out the pilot air jets.

 

The quality control on them is way off, I think, and they are nothing on the Mikuni ones I have since fitted, which do not leak...

 

Not sure if I got fakes or if Tourmax stuff has just gone downhill in general?  If you buy direct from Mikuni, it's cheaper than buying them in a Suzuki bag.

If you buy pure gold from a bullion dealer, it's cheaper than buying carb parts from Suzuki.

[TonyGee]

2 hours ago, Nick said:

Tony,  I had this with brand new Tourmax float valves recently - they leaked like a sieve, fuel pissing out the pilot air jets.

 

The quality control on them is way off, I think, and they are nothing on the Mikuni ones I have since fitted, which do not leak...

 

Not sure if I got fakes or if Tourmax stuff has just gone downhill in general?  If you buy direct from Mikuni, it's cheaper than buying them in a Suzuki bag.

yeah ive heard about fake tourmax stuff getting in !!!  I think ive been lucky with what ive used so far   theirs no substitute for genuine parts but when you are on a very tight budget the genuine stuff can be out of reach    

[PaintItBlack]

I had similar experience after rebuilding my B12 carbs, using cheap Eblag kit, new float valves didn’t seal well in the new seats,

had to change engine oil twice after carbs flooded,

got a better quality tourmax rebuild kit and problem solved,

another lesson learned, don’t waste your hard earned on cheap carb rebuild kits

[bunk]

I just put tourmax stuff in my bike and was surprised to see metal on metal sealing surface on the needle/seat. Im used to a rubber coating on the needle to seal things up. 

[CockneyRick]

1 hour ago, bunk said:

I just put tourmax stuff in my bike and was surprised to see metal on metal sealing surface on the needle/seat. Im used to a rubber coating on the needle to seal things up. 

I do have lots of spares from various carbs (unfortunately not bagged & tagged) but the rubber coated ones are few & far between.

Most older bikes never had these as standard, my bikes date 78, 84 & 86!

[Wagola]

On 8/26/2024 at 7:24 PM, Captain Chaos said:

I think the bike is suicidal and wants to self-combust because it has an ugly paintjob.

Its just trying to hide itself in the gravel driveway ??

[Nick]

It wasn't cheap at about 100 quid for four valves and seats, but worth it in terms of the aggro of carb removal and fuel in the sump etc.  Suzuki want 75 per carb, ffs!!

As you can see, the Tourmax ones aren't chamfered at the top of the rubber and were just a bit naff quality wise.  Shame, as I've always used their stuff and rated it...

 

[CockneyRick]

Well after a lot of assembly/disassembly trying all sorts of parts & options, it came down to the valves themselves.

Tried several spares, but the ones that worked are the same as the ones above.

Dunno if they're gen or copies, just 4 that i had that matched in a tray of 20 odd!

Also put the Viton O rings I forgot I had on too.

So when doing the external float/fuel level check, where does the level in the pipe stop? Mine currently sits about 3-4mm above the bowl to carb face.

Meaning the bowl is completely full + the 3-4mm extra?

[Baron]

I have noticed that Tourmax float valves will work for a max 2 years until they start to leak. I have bought 3 sets and installed those on 3 different set of carbs with same result.

Genuine float valves are pricey but quality is superior compared to aftermarket ones.