Yamaha Blaster Wont idle at all!!!

[Charles hoffman]

Hello all!! i have an 89 Yamaha blaster that just recently started running really weird. It will not idle at all and it just started doing this. Things that I have noticed is as follows. The bike will only start if I hold the throttle at about 1/4 to a little more. when i hold it in this position it sounds like it is missing (sputtering) If I snap the throttle up it bogs with big puffs of smoke coming out and revs up . I have tried adjusting the air fuel screw several times and this does not help it only causes it to do the same thing and backfires sometimes. I do not have tors on the quad. When i pull the choke out it does not help the problem. My carb has been cleaned and rebuilt. The plastic piece that sits in the bowl over the main jet is gone. Will this affect anything or not? please help

 

[82cutty]

Check the compression and leak test . Do you have the washer under the main jet ? You need the plastic piece too . Reeds could be bad also

 

[Charles hoffman]

I've checked reeds they are good....... compression and leak down test all check out.... one thing that I did notice is the cap that screws on top of the carb feels like it is stripped. I can get it tight but if I turn it ant more it keeps turning. But this didn't effect the way it ran before.

 

[jus_me]

The plastic piece is a slosh guard. If your just sitting there idling it won't make a difference if you out riding bouncing around it could. Is float height correct, you said carb is clean can you see light through the jets? What all did you remove from the carb to clean? I have seen a few times people mix up the pilot jet and the mixing jet from the float bowl.


Reeds have no chips and are seated tightly? No light shining through? Also check to see if your woodruff key is not sheared off. If your flywheel shifted (sheared key) any at all it would run awkward and also backfire

 

[Charles hoffman]

So after trouble shooting a little more I've come to the conclusion that the quad is running lean. When I pull the choke out all the way it runs as if it is normal. I know for a fact that all my jets are clear. I soaked the carb in cleaned and install all new jets and the bike ran fine. The reeds are good as well when inspected. Not to mention they are new. I guess my next step is to look for an air leak near the carb. But how would one do this

 

[MURPH]

 

[Charles hoffman]

I got the quad running good now. Turns out that the problem came from the cap coming off the oil inlet on the carb which i guessing was pulling extra air in causing a lean condition. Ive done three plug chops and I'm getting a nice coffee color. back to the trails whoop!!!!

 

[yammy15]

I got the quad running good now. Turns out that the problem came from the cap coming off the oil inlet on the carb which i guessing was pulling extra air in causing a lean condition. Ive done three plug chops and I'm getting a nice coffee color. back to the trails whoop!!!!

Hey im having similar issues with my 97. It wont idle at all without me touching the throttle ever so slightly. I am wondering if u still have the tors system on yours.?? I was wondering what your air screw was set at? And also the idle screw on the top of tors system? underseat. thanks