new top end ran then wont start

[dakdak360]

Hi I im new to this and do not know where to post this, but here is my problem.
I have a 93 blaster, i have had it about two weeks now and it ran great when I first got it but one night i was riding not to hard and it just locked up on me so i figured i blew it so i tore it all apart and got a new veto's super stock piston and rings and all the gaskets. When i took the jug off in the first place i had to get it honed and got most of the deep scratches out so i put it all back together right and with all the new parts it's a std bore. Today i got everything done and ready to go so i can break it in and it took like 10 kicks between choke and no choke and it finally started i had to give it a little bit of throttle so it wouldn't stall and i let it warm up and i started the first heat cycle and got the second one done then i was letting it idle down then it just quit, and couldn't get it started again. So i let it sit and i tried thinking what it could be so i tried pull starting it and it would kind of fire a few times and it started a couple of times and when it did run it would bog down and just cut out idk what it could be it's either not getting enough fuel or it had low compression. Oil block off kit, tors system deactivated everything else is stock i took the carb off and cleaned it

Please help thanks
Alex

 

[Wifesblaster]

Well if you had to hone a worn standard bore cylinder I would sy it's time to bore it. You should have measured the cylinder before you ordered the piston. I would pull the cylinder and put some inside mic's on it and post results.

 

[DUALSTROKE]

Well if you had to hone a worn standard bore cylinder I would sy it's time to bore it. You should have measured the cylinder before you ordered the piston. I would pull the cylinder and put some inside mic's on it and post results.

Agreed!! You should do a compression test and see where you are at on compression.It does sound like you needed a bore and tried to get away woth a hone.A compression test will help answer that though.Keep us posted

 

[ChrisZx7]

Hi I im new to this and do not know where to post this, but here is my problem.
I have a 93 blaster, i have had it about two weeks now and it ran great when I first got it but one night i was riding not to hard and it just locked up on me so i figured i blew it so i tore it all apart and got a new veto's super stock piston and rings and all the gaskets. When i took the jug off in the first place i had to get it honed and got most of the deep scratches out so i put it all back together right and with all the new parts it's a std bore. Today i got everything done and ready to go so i can break it in and it took like 10 kicks between choke and no choke and it finally started i had to give it a little bit of throttle so it wouldn't stall and i let it warm up and i started the first heat cycle and got the second one done then i was letting it idle down then it just quit, and couldn't get it started again. So i let it sit and i tried thinking what it could be so i tried pull starting it and it would kind of fire a few times and it started a couple of times and when it did run it would bog down and just cut out idk what it could be it's either not getting enough fuel or it had low compression. Oil block off kit, tors system deactivated everything else is stock i took the carb off and cleaned it

Please help thanks
Alex

Mine didnt come with a pull start! What am i missing?

 

[DUALSTROKE]

Mine didnt come with a pull start! What am i missing?

Pull start= pulling with another quad to start

 

[ChrisZx7]

Pull start= pulling with another quad to start

Lol i figured, was just messing with him.

 

[dakdak360]

Thank you guys for getting back with me so soon and the new piston is 65.95 mm and the bore was like 66.2080 so i figured that the rings would make up the differance, but i will do a compression test and let you know. thanks again!

 

[DUALSTROKE]

65.95 piston??? what brand? I am no expert but usually a cast piston will have around .0015 piston to cylinder clearance and a forged piston will have somewhere around .0025 give or take.Again I am no expert so don't hold me to those numbers,but there real close. BTW welcome to the forum.Where abouts are you from?

 

[dakdak360]

It was a Vito's forged super stock piston, and that's what the numbers were on top of the piston head, and thank you it has been very helpful with all the problems i have been having and what other ppl have done. And in the first place i should have taken the oil injection pump and tank off so this would have never happen but you live and learn lol. and i am located in the middle of Michigan six lakes to be exact.

 

[Larry's Shee]

Don't go blaming the oil injection for a worn out cylinder X(

If I'm doing the math right you have about .25 piston to cylinder clearance.

Who measured this to begin with? A shop? Was it checked for out of round or taper?

@Duel, a 66 bore would use a 65.95 piston, giving .05mm clearance

 

[joeak47]

And in the first place i should have taken the oil injection pump and tank off so this would have never happen but you live and learn lol.

What does the oil injection system have to do with it? The yamaha "Autolube" oil injection system works perfectly. I run the oil injection with ported cylinder,re-chambered head,matched transfers,high compression,etc with ZERO issues. Did you have the oil injection system removed,disconnected,or partially disassembled at any point? If so,did you bleed the system? I see that you didn't mic the bore,and also used a forged piston. There is no way to know your clearance without doing so. Was the engine warmed up properly before riding? Thats very important with a forged piston,otherwise the piston can "four corner" seize by heating up and swelling up faster than the cylinder.
Did you do the heat cycles,and then re-torque the base nuts and cylinder head nuts?

 

[Blaaster]

I see no mention of a leak test, was one done before you started the motor after rebuild, if so how long did it hold 7 psi.

 

[gb blaster]

Yeah Ill agree with blaaster kn the leak test!

Was on preformed? If not that could be an most likely is ur answer.

Also did u hone ur self or did a qualified shop as that it only needed a hone sounds like u may have tried to cut a corner, an it's gonna cost!

Btw who did ur position measurements?