[SamUK]

Still having issues with trx250a carb... replaced the float, replaced the jet for an OEM which cured it temporarily but I still get a leak once I stop and the ATV is ticking over.
I can't find a second hand OEM carb anywhere and I'll be damned if I'm buying a Chinese knock off. Will an ATC250ES carb fit straight up to the TRX250 inlet rubber? The top of the carb is screw type on the ATC so I assume I'd just run an ATC throttle cable?

 

[retro]

I don't know the answer to your question, but has the seat for the float valve on your TRX250 carb worn out? The tapered angle in the brass seat gone, or worn too wide? Is the seat pressed into the carb body? If so, I would disassemble the carb completely then drop it into a small pan with some oil (any kind of oil, vegetable oil if you wish) in it and slowly heat the oil and carb up on a stove until its about 250-275 degrees (F) then pull that valve seat out of the carb body. At that point you can either replace the worn seat or attempt to fix it with some super-fine jewelers rouge or polish. You can test it while its out...

 

[SamUK]

Thanks retro, I did clean the seat up using toothpaste (the only light abrasive I could think of) and a cotton bud, I then replaced with an OEM jet. This worked for a few days so I thought, great, that's one project finished but obviously not. What I may do before stripping the carb again is attempt to polish the seat in situe with jewellers polish, I never thought about using that, good shout.

I'm just sick and tired of taking carbs apart now though!! Haha

 

[retro]

Yep, I know the frustration of fixing stuff over and over... I'm not sure about the angle the seat is cut to, but maybe it is close to 60 degrees? If so, you may find a small enough phillips head countersunk screw that will fit down the seat hole... that you can use to maintain the seat angle at 60 degrees while you "cut" the seat lightly with a fine polish.

I've used toothpaste before as well... works great for some things, but that brass seat is soft and can benefit from a finer abrasive. The end result must be a "polished type" of finish for the needle valve to seal...

Hope you can figure out something simple and quick.

 

[SamUK]

Thanks for that. I'll give it a go and post back here with the result. I suppose the one good thing about fiddling around with carbs over the last few months is the experience gained, I knew very little about carbs if I'm honest, I'm getting there now though

 

[fishfiles]

Sam , I have had quite a few TRX250A's , don't run any of them any more and had a lot of carb problems and all the headaches were the needle valve sticking , either open and dripping gas from the over flow tube or sticking and not letting fuel into the carb , I think the problem is the rubber tip on the needle getting gummy ,I even once bought a brand new carb and it did it , and I never put ethanol gas in my bikes and always add stabilizer and Sea Foam to every 5 gallon can , I replaced one needle with a solid metal needle , what it came out of I have no idea , you could try to match the needle up and do away with the gummy tip one , also do you have a fuel filter before the carb , any little piece of trash will make it not seat

 

[SamUK]

Ahh ok. I'm glad I'm not the only one here who's having/had issues. This is why I'd considered trying a different carb but for the same CC. I just wasn't sure if the inlet rubber was the same size on both machines. I think if I ran an ATC throttle cable it should work fine as the ATC carb is screw top rather than the side entry cable on the TRX.
I've never ever seen a solid metal jet, I'll have a look and see if I can find anything.
I've cleaned the carb out several times along with the tank and fitted a new fuel filter. I even cleaned the carb and ran fuel through a bottle into the carb just incase any bits of junk were getting in there.
If cleaning/polishing the valve seat doesn't work this time around then I'm at a loss really, completely out of ideas apart from trying another carb. Trying to find a TRX250A carb is proving difficult though at the moment, hence the possibility of fitting an ATC carb.

 

[fishfiles]

Sam , not talking about the jet , the needle valve , it is the plunger that hooks onto the float and goes into the brass fuel inlet port , the tip of the OEM needle is rubber , the rest of it is like maybe brass or some alloy , look around and you can find one exactly the same but all brass , the main store NAPA , has a whole box of them ------------ I remember the 250 would sit for 3 days and no problems and I would come home and the contents of the fuel tank was on the ground , I learned to always turn the petcock off on those 250's , I had a lot of trouble with that needle valve

 

[SamUK]

Sorry, yes I know what you mean,with the tapered rubber tip. Yeh I cured it, then it leaked again out of the overflow, so I cured it.... Yep, then it leaked again! It's a pain though, as soon as you loose off the throttle and stop for a few second it starts leaking, not ideal when the engine is hot.
What is NAPA? I'm struggling to source jets etc here, I emailed Honda but as per usual main dealer here don't want to know unless you buy a new ATV.
I dropped lucky with the rubber tipped OEM valve, found NOS on eBay.

 

[fishfiles]

What is NAPA?

NAPA is an auto/truck parts company , that has a lot of stuff , they have a huge catalog as most satellite story are not big enough to house everything , but lucky for me I live close to a main hub