Limited Beast leaking fuel

[2010limited]

Ok So after screwin' around some more I found my intake leak. The gasket between the intake runner and the cylinder was torn and leaking bad.

Replaced it. And re installed the mikuni. It idles perfect and ran awesome at around 1/4 throttle, but anything more and it fell flat on its face. So I think you NEED the bigger jets in it for it to work.

So I swapped back to the original carb, and got the machine running. It still is running kinda crappy, but I have to play around with the air fuel and such.

When I give the quad a quick rev, it kind of holds at high rpm, then drops a bit slower. So i'll have to adress the issue.

[Weldangrind]

Originally Posted by 2010limited

When I give the quad a quick rev, it kind of holds at high rpm, then drops a bit slower. So i'll have to adress the issue.

That's a vacuum leak. Either the new gasket you put in is still leaking, or the end that meets the carb is leaking.

TurboT had the same symptom, but he has an o-ring where the intake tube meets the head. The o-ring groove was cut too deep in the tube, so the o-ring wasn't squished up against the head surface. My hillbilly answer was to stack two o-rings. That was a couple of years ago, and it still runs great.

BTW, you can find replacement jets at your local Yamaha dealer. Just unscrew the jets from the carb and take them with you.

[2010limited]

I'll have to check for more leaks then.

Will the mikuni work with the stock jets? Or do you HAVE to upgrade them?

[Weldangrind]

The 100 main will not deliver enough fuel for WOT, and the 20 slow jet will take forever to warm up, and even then it won't idle if it's cold out. Jets are cheap. Buy some. They'll make you happy.

[2010limited]

I can't get out to the machine today, but I wanna stop and grab some jets, do you know the part num bers for the jets I need? and which size are they again?

Thanks!

[Weldangrind]

The part numbers might vary based on the supplier, but the most common numbers are:

Slow jet: VM28/486-25 (meaning 25 slow jet)
Main Jet: N100.604-110 (meaning 110 main jet)

Happy shopping.

[2010limited]

Awesome thanks!

They didn't hsve any in stock, so I ordered them, should be in this week!

3.49, and 3.99 , CHEAP. lol.

[2010limited]

Ok so installed the jets, and it seemed to run good, except there was def still a vac leak. After using the wd40 method, I found that the intake tube was actually cracked, which is what caused the original gasket to tear.

So I dremeled it out a bit, and filled it with jb weld.

The machine seems to run ok, still have to tune up the settings on the carb as it seems to idle high, then if you leave it drop down after a second.

The mikuni made an amazing difference with starting though, the machine barely turns over.

[Weldangrind]

Originally Posted by 2010limited

Ok so installed the jets, and it seemed to run good, except there was def still a vac leak. After using the wd40 method, I found that the intake tube was actually cracked, which is what caused the original gasket to tear.

So I dremeled it out a bit, and filled it with jb weld.

The machine seems to run ok, still have to tune up the settings on the carb as it seems to idle high, then if you leave it drop down after a second.

The mikuni made an amazing difference with starting though, the machine barely turns over.

Glad to hear that the Mikuni is an improvement, and that you found the leak source. If it still doesn't return to idle immediately, perhaps it's time for a new intake tube.