TZR125 carb, more fuel outside than in.

Git · Brolly Dolly Joined: 17 Dec 2003 Karma :

Hi, I have a bit of a problem.
I have this carb in front of me and it's leaking fuel out the overflow pipes.

I have checked the float heights, they ok.
Floats look fine, don't think they are split.
Needle valve and seat look good.

But,
the needle is shot and I would not be surprised if it has taken the needle jet with it, it will be getting these as soon as I can order them next week but could they cause the problem of the carb filling up with too much fuel when the engine is off? I always thought the needle valve controlled this?

Any thoughts appreciated Smile

BlueNinja · Trackday Trickster Joined: 14 Dec 2004 Karma :

Hey.

Could be your fuel switch diaphragm nackered, and its gravity feeding heaps of fuel into the carb?

Other wise rebuild the carb with new gaskets, and the parts you mentioned that were damaged. Then put the carb back, and run it on Redex carb cleaner. Thumbs Up

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Git · Brolly Dolly Joined: 17 Dec 2003 Karma :

Well the taps brand new so that should phase that out.
The only gaskets I can see are on the float bowl and on the needle valve holder, may just buy them aswell as they do have age against them but look fine..
Can only try an see.

cagiva gezzer · World Chat Champion Joined: 17 Mar 2003 Karma :

Which overflow pipes?
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"because one stroke isnt enough and four strokes waste two"

Git · Brolly Dolly Joined: 17 Dec 2003 Karma :

The one on the float bowl and one further up, a tiny one, about an inch from top of the bowl joint.

Now with picture..

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Sounds like it is the needle valve leaking or the floats holed. Take the floats off and check them (are the clear, black, solid, etc?, some are foam filled so if they leak they will just get very heavy). Also check that it pivots smoothly.

The needle jet will not have any effect on this.

All the best

Keith
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Git · Brolly Dolly Joined: 17 Dec 2003 Karma :

Thank's greatly for that, certainly cleared allot up.
The float pivots fine, all smooth there. it's a black plastic float, not sure if it's foam inside or not, sounds pretty solid.

I just gave the float a dunking in a bowl of water, it's still floating and doesn't appear to be leaking air when under..,going by the state the needle/jet was in, 2 years of water/mayo, crust and rust, getting expensive now, better tell him my fears, I need more money for another bit Shocked

Needle valve or float/both.. do yamaha do a rebuild kit...
/looks for carb dealer

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Sounds like the needle valve then. They should be fairly cheap from Yamaha.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

simon1221 · World Chat Champion Joined: 28 Jul 2004 Karma :

Petrol used to run out of mine, but never on the higher breather pipe, just the black one underneath. Confused

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DNA50 (sorry) ->> TZR125l >> GPZ500S

Git · Brolly Dolly Joined: 17 Dec 2003 Karma :

The shopping list so far.

Needle set, nozzle, needle valve, needle valve seat.
guess how much Shocked

£150

/falls over

simon1221 · World Chat Champion Joined: 28 Jul 2004 Karma :

Thats a bit bollocks, could you not just order the parts from somewhere who does mikuni carbs and give them the model number?
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DNA50 (sorry) ->> TZR125l >> GPZ500S

Git · Brolly Dolly Joined: 17 Dec 2003 Karma :