Yamaha blaster going wide open without giving gas

[Zbskater400]

So I just had my Bottom end rebuilt because my case cracked and I just put a fresh top end in it with all new gaskets and everything torqued correctly but when I finally got it started it went wide open throttle like as if I was giving it gas and i wasn't giving it any throttle because the throttle was not even hooked up yet i just wanted to start it I've been trying to figure it out all day and all last night could it be my idle adjustment or air fuel ratio ? Because I've messed with both of those things the whole day and it would still go wide open so I have to quickly shut it off and at one point a was messing with the idle and air fuel ratio and when I started it. Right as it started it sounded good then 2 seconds later it would go wide open just need someone's help thank you !

 

[89blaster89]

it sounds like you have a major airleak, leak test it, what kinda gaskets did you use? the green ones are crap and cause leaks, i had one and it was fine for 7 years but i got lucky i guess.

 

[MrTwoJay]

If the carb slide is completely down, then it must be a air leak. Test and fix immediately.

 

[Zbskater400]

I can't even test to see if it's an air leak because the thing won't stay running because I don't want to blow it up while it's going wide open and I don't know how to do bottom ends because I think it's a air leak from below and I used yamaha gaskets the metal / led base gasket. And a brass head gasket

 

[89blaster89]

 

[Herpderplol]

It should NOT be running at all until you leak test it...

It does not need to be run for a leak test...

 

[Blaaster]

Idle adjusting.

Set float level, make sure that all jets are clean and fuel flows freely from the float bowl drain when the screw is cracked open.

Start with air screw 1.5 turns out.

Set idle screw so that it has some sort of idle. With TORS it is the big screw under seat on top of unit. With no TORS is is the brass screw midway down carb body.

Warm up motor and then set idle screw for a faster idle, 2000rpm+

Adjust air screw either way to get the fastest idle.

Adjust air screw a little at a time leaving 10 secs or until the motor responds.

Re adjust idle screw for desired idle .

 

[Coollaxer]

when i rebuilt my blaster the same thing happened to me but when i put the throttle cable back on and hooked up the carb the cable was all twisted and tensed up, but the thumb throttle ferlt perfectly normal...when i kicked it over it went right to full throttle and i took the cable off and put it back on and it was fixed.....just saying what happened to me , goodluck

 

[bansheedave]

He said he had a cracked case. Depending on where it was and how it was fixed, I would assume it is either leaking air where it cracked or if fixed correctly, the case sealing agent, aka yamabond, wasn't applied correctly. Or he rolled a main seal lip installing the crank. Do as above and pressure test it.

 

[Coollaxer]

Listen to these guys lol^^^^^^^ they know a lot!!!!

 

[Zbskater400]

Thanks bansheedave my case had cracked where the shift shaft is and I bought a new left case I didn't fix it my brothers friend did and he said he know how but i honestly think it's the crank seal I think he may of rolled it

 

[Blaaster]

Leak test before even thinking about starting it again, and report back your findings.

 

[Zbskater400]

Thanks guys come to find out it was a bad crank seal I replaced it and it started 1st kick the kid put the clutch side crank seal on the stator side

 

[Awk08]

Thanks guys come to find out it was a bad crank seal I replaced it and it started 1st kick the kid put the clutch side crank seal on the stator side

nice find and save, thanx for reporting back

 

[Zbskater400]

Your welcome Thanks for the help means a lot !