[Joey.p]

So I got this 1989 trx 350, litteral peice of garbage when i got it(it was growing moss). Ive basically resurcted this thing and got running pretty good. It starts up idles great and runs great. All my fluids are fresh and my fan is doing its thing but its got a weird bug. After riding for five minutes I slow down to stop and its idle seems to be struggling and than dies. But it fires right back up and I carry on until i have to stop again. Its got a fresh carb and feul pump. Thanks and any help is appreciated.

 

[retro]

Hello,

Is it an OEM original carb? OEM fuel pump too? If either are china replacements you'll need to get them off there and fix the original carb.

If the carb is OEM, and assuming the carb is set up to spec per the FSM, the choke plunger may have the lipped seal on it installed upside down (or worn/rotted out), or the cable could be holding the plunger open a bit.... or the plunger needle could be broken off?

Another possibility is the pilot jet adjustment screw (idle enrichment) is missing the tiny o-ring on the end of the shaft, OR it simply needs to be fine tuned from the factory setting specified in the service manual for your machine.

We have been seeing an increase in numbers of new forum members showing up with an old TRX350 recently... and I'm loving it!

Welcome to the forums!

 

[Larryw]

Complete carb rebuild and clean.. Fuel filter and check how much fuel pump is running..

 

[Joey.p]

Well the feul pump is from lordco and the carb is from china, but they seem to be performing pretty great! I did bot place a cable on the choke plunger yet, i had no idea it had to be open a bit! Ill report back with results this week! You guys may have just solved my problem! Thanks!

 

[SamUK]

Just to add, as said above. If your China carb works after you've sorted the choke cable be prepared for it to fail, they are junk.
I would also advise rebuilding your OEM carb so you can swap it over.

 

[retro]

Can't help you if you have useless china junk on it. May as well get your original carb ready cause its going back on it...

 

[Joey.p]

Well fair enough ill see how far it gets me and when it does fail ill be sure to let you guys know you told me so

 

[SamUK]

IF the China carb does work, make sure your fuel mixture is correct by looking at the spark plug, I'd hate for you to bugger your motor and I certainly don't trust Chinese parts.

 

[Joey.p]

Ok so all hell broke loose with the chinese carb, you guys were right. I put the original back on. Put in fresh gaskets and cleaned it up. Took it out for a spin and everything went pretty flawlessly until it died and wouldnt start again. Im assuming the plug just got really fouled from running too rich with that chinese carb. It was pure black and sparking every where except for where it should be.

 

[Joey.p]

Also there is a rubber plug for these carbs right? I made one from some material that i did a simaler thing to with my motorbike. Just making sure i put it in the right hole. Its the second furthest from the main jet correct?

 

[retro]

Here ya go, from section 4 of the FSM:

You'll need to sync the throttle too... if you haven't yet. After 30 years they are way off... and will sputter and run like crap. Section 4...

Get another NGK and have fun with it!

 

[Goober]

Do you have the service manual?

There is a fuel pump test--is not a pressure but a flow rate. Note do not use your wife's good measuring cup for this?

I added a pic of the throttle valve synchro

A problem with using nonOEM parts it makes it hard to diagnose performance issues. But you sound like you're on the right track.

Some rebuild kits have the plug and some don't. Most members here have tried the Shindy carb rebuild kits I have not yet tried on OEM kit

 

[Joey.p]

Ok got it! Just curious why do these carbs have rubber plugs? Ive seen this on a few machines and im confused why that jet is even there if it does nothing?

 

[retro]

Ok got it! Just curious why do these carbs have rubber plugs? Ive seen this on a few machines and im confused why that jet is even there if it does nothing?

I don't have a carb in my hand to look, but the hole where the rubber plug goes may be a drill hole to connect one passage into another passage. Its common practice to drill holes for internal interconnects, then plug where the drill entered the casting.