Looking for some much needed technical support. I'm working on a 96 TRX300. The bike starts easily and idles well. The problem is that it will not take any throttle without bogging down and dying. When I say any I mean "0". Touch the throttle and it dies. Heres what I have done so far.

Carb removed, soaked in Gunk and flushed out with carb clean.
Installed new kit including needle and float.
Float height checked and the fuel level is at 1/16" below the bowl / body mating line.
Lowered the main needle by 1 "click" from the orginal setting.
The fuel / air mix screw is set at 2 turns out as a starting point.

None if the above has had any effect on the problem. It seems like it's not picking up any fuel from the bowl. I'm thinking it may be the diaphram although it looks to be in really good condition. Is there a way to properly check it other than visually? What other things could cause this?

Thanks in advance for any and all input!!!!

 

Did the atv run the same before repair kit?You have check pilot jet[slow speed jet] passages throu out the carb? When you say lowered main needle do you mean raise e-clip up to lower needle jet? of coarse that is an leaner mixture, when you lower needle its goes further down in jet holder, If you lower e-clip than that will raise needle jet and give you an richer mixture. What kind of shape is your air filter in?

 

I took it on as a repair job, I'm not sure if it had the same problem before the kit or not. All I was told is that it "won't run". I rasied the clip to lower the needle. The air filter is bran spankn new.

 

I gots a 300 honda and the same thing happened to mine.. would idle all day as soon as i would touch the gas it would bog or just die.. i brought it to some back wood mechanic and he took off the carb and cleaned it all out and its allset now.. he said some of the places fuel were supposed to flow through had varnished up bad.

 

Well Unit, I guess I'm a back woods mechanic too. I may have to start all over and clean it again. One thing I'm going to try tonight, is to manually work the slide (thru the air box) while it's running to see if it will pick up rpm's. I think this will tell me if I have a problem with the diaphram.

 

I would also check the fuel flow to the carb from the petcock. It may be restricted.

 

Just an update. I could not reach the slide thru the air box as I thought, so I took the carb off and apart. Cleaned it again using a whole can of carb clean. While i was spraying it out, a broke O-ring came flying out. Not sure where it goes. I've got to get the drawings to find it. I did notice that for some reason I was not getting fuel flow from the tank last night. I checked it before and everything looked good. Not sure what changed here. Going to reinstall it tonight and see what it does. Will keep everyone posted on the results.

-SD

 

Another update.
Reinstalled carb, this time without the air box so i could get to the throttle slide inside the carb. Manually lifted it with the bike running and it had no effect on the rpms. Now what?

I'm thinking since this had no effect the slide and diaphram are probably OK? And that I might have a vacuum leak. I don't think it's in the rubber manifold that connects the carb to the head, but it may be leaking around the gasket on top of the head.

Any and all inpt is much appreciated.