Now I have carb issues, will not pin to WOT

[dirtrider73068]

Well I tinkered with it some more, in fact I put it all back like it was when I started. Even put the stock pump spring back in and it still won't pin WOT from idle. Something is wrong, it also is popping or coughing back into the carb just idleing. I almost think it needs to be rejetted, but it didn't do this before I took it off and tinkered with it. Maybe the carb boot is cracked or something happend to it?

 

[bones]

yep id check the carb boot maybe you cracked it pulling the carb off

 

[dirtrider73068]

Great thats all I need now. I know there was a couple in here somewhere about carb boots and some haveing issue with jetting and what the did to fix it but couldn't find them.

 

[elwood]

start the quad spray starting fluid on the boot and hold the carb and move it around, hopefully the starting fluid will get in the crack and rev the motor if there is a hole somewhere in it. Temp fix is permatex on the crack, but fix it right means replacement, they run around 25 to 30 new on ebay

 

[dirtrider73068]

Tried that and nothing changes so its not the carb boot. So that means its got to another issue or jetting. If its doing it right at idle or off idle thats a pilot jet circuit right? Then from about 1/4 to full open is the main and needle jet circuit right? So the jet thats in it now is a 136 could it be thats its too lean, but it ran fine with it in there till now. Or maybe the pilot jet needs to be bigger. It acts like its starving for something. If I put my hand over the intake and block most the air flow it will rev up, this means its lean. So its making me think it needs to be rejetted.

 

[bones]

1/4 to 3/4 is need
3/4 WOT in main

 

[dirtrider73068]

So this could be a pilot jet problem? But what has me razzed is it ran fine till I took it apart and now but back just like it was before I took it apart and its still acting up.

 

[bones]

http://www.yfm350.com/forums/showthread.php?t=21231 maybe this might help ... i dont know man maybe you got some dirt in there or something i have no clue

 

[dirtrider73068]

It explains the workings, though not what to do with carb issues due to jetting. I need somebody that has experienced this and found what to do to fix it or what they did to fix it.

 

[elwood]

if it didn't have the problem before you rebuilt the carb and does after you did, sounds like you need to tear the carb apart, reclean it and make sure it's together correctly. Here is a vid of the 93 up carbs i think only difference is the slide for the needle jet http://www.youtube.com/watch?v=q0n0roAeQ_Y

 

[dirtrider73068]

I have gone back into this carb 4 times to make sure everything is in order and everytime I spray it with carb cleaner and blow it all out. I am still wondering about the needle jet pilot jet and main jet if there is something off about those. But still if I put it all back like it was before and still this problem then there has to be something else wrong, but shouldn't the insides is really really clean.

 

[elwood]

maybe you have a bad gasket? are your jets clear? when you sprayed it with cleaner did you spray all the passage ways to make sure none are clogged? Is your airfilter clean? Have you tried turning the idle up some?

 

[dirtrider73068]

A bad gasket where? I am sure my jets are clean I have taken them out sprayed them, blown them and held them up to a bright light and looked down them all are clean. Sprayed every spot hole jet that I could, don't know where half of them went or go, couldn't see where the spray went.

And yup turned the idle up still did it, even turned it really high it popped some but would rev, but by then it was idleing at a good pace.

 

[MotoArts]

Sprayed every spot hole jet that I could, don't know where half of them went or go, couldn't see where the spray went.
.

First, idle speed doesn't have anything to do with the problem. I'll bet my lunch money on that, and I love to eat

Sounds like a accelerator pump problem to me.
You have to VERIFY that all ports and jets are open. There is a passage that goes from the acc. pump, down through the bowl, through a passage in the bottom of the bowl, and up to the brass "straw" in the the carb mouth. That straw has an outlet hole aimed directly at the slide, into the carb body. Venturi vacuum isn't sufficient at idle to pull the fuel out of the bowl at low engine speeds, thus the need for an accelerator pump.
If the bowl passage or the "straw" isn't open, you have no acc. pump squirt and the engine will stumble on the mass inrush of air (without the compensating fuel squirt) off of idle.
Both of these passages through the bowl and the brass straw are very tiny and easily plugged.

Gotta verify the flow, bro... every passage has an in and an out...

 

[dirtrider73068]

It will squirt gas out of that straw tube into the throat of the carb and a good squirt too. I tried to remove that tube but it didn't want to turn easy so i left it alone. But motoarts, why would it work before I took it apart but now it won't work. I check the passages in the bowl there was junk in the pump part in the bowl but I sprayed it out and blew it out real good, maybe I got something inside that passage in the bowl, I can take it off again and check to see.

 

[MotoArts]

While you're at it, I'd recommend draining the tank, removing the petcock, cleaning the sock on the petcock, and install new fuel line with an inline filter before reconnecting to the carb. That way you're sure everything's clean upstream, and at almost zero expense.

I outlined in an earlier post that I had the same/similar problem with my carb. Was spotless, engine ran perfect until I put a new top end on it. Both the pilot jet and acc pump somehow had blockage after assembly (that had nothing to do with the carb internals).

Makes ya invent new swear words sometimes, LOL!

 

[dirtrider73068]

I have a inline fuel filter already on it. If something got in there it had to be when I took it apart the first time. I keep wishing why the effing hell did I even mess with it.

And yes you invent new swear words and phrases to go with those words. I am at the point I want to say screw it and just sell it like it is and get away from it. But then if I do I will regret it.

 

[dirtrider73068]

Ok guys messed with it one more time, got it all ready got a good space to work on, pulled EVERYTHING off the carb except the choke rod, pulled every jet everywhere I could and blew it all out real good, even the accel pump in the bowl, one thing I noticed is in the bowl with the pump ports it seems like it has a check ball or something air will only go one way, so I loaded it with carb cleaner and blew air behind that. This thing is so spotless you could drink out of it, put it all back together very carefully. Put it back on, think I got this part down to a art, I can take this carb off in about 3 minutes.

Start it up and same damn thing, so keeping trying thinking maybe the pump not squirting yet, so in the mean time I turn the mixture screw in till it chokes off, then back it out gooseing the throttle as I go, I get the mixture screw almost till it falls out and it revs up great, turn it back in and it coughs. So does this mean a bigger pilot or main? I have it set (just guessing) about 3-4 turns out on the mixture screw.

 

[duneracerweston]

It needs bigger main I do believe