[dandawson]

Hi I have a TRX300 that is driving me crazy. the bike was running perfectly until a few months ago when it just started spluttering, exploding out of the exhaust and stalling. Initially we thought that is was a fuel issue so we changed the filter, still the same result. We then cleaned the carb 3 times with no change. We have now installed a new carb and another new filter and changed the fuel and it's still exactly the same. I read another forum that said try changing the spark plug but again this has made no difference. If you start the bike it will idle quite happily it's when you increase the revs that the issue occurs. Sometimes if you're very gently on the throttle you can ride the bike but it has lost most of its power.

Can anybody give me any advice on what could be causing this?

Thanks

 

[fishfiles]

split or hole in the diaphragm of the slider will make you lose mid range to high speed , makes it feel like the engine is out of time , which may also be part of your problem , you don't even have to take the carb off the engine to check the diaphragm , unscrew the four screws on top and pull it right up and out the carb body , check for a split around the base where it attaches the plunger

 

[SlammedRanger]

I would be looking at a timing issue or a cdi box is bad. Either could be the culprit. Check timing first since that will be obveous if its out. If timing is good i would then change the cdi box. The new carb is a oem honda carb right?

Welcome to the forums!

 

[SamUK]

I’d also check the timing, I would also be tempted to inspect and clean the carb again, honestly these Honda carbs need to be surgically clean in order to work properly. I was only successful on my 6th attempt!

 

[Goober]

Put the old carb back on. Check for fouled plug.
You might have bad CDI or stuck valve.

 

[shadetree]

what year trx300 is this ??. I say the c.d.i. is bad ?, reg/rec bad ?, stator is bad ?. not enough fuel reaching carb ?. oem carb or china carb ?.