blaster no top end

[gavinski]

I have been reading the forum for a while now, but I still cant figure out my 92 blaster. I rebuilt the engine,rebuilt the carb, did a pressure check (no leaks) it starts fine but when I rev it I can hold it wide open it and it acts like a rev limiter it doesn't starve for fuel just has no top end I am at my wits end!

 

[usetheBFH]

When you say pressure check do you mean compression test or leak down?

 

[gavinski]

leak down held 9 psi for 8 min
just rebuilt the motor didn't think to do a compression test .

 

[Blaaster]

What mods?
What jets and needle setting?
Has the float level and idle been set correctly?
Is the carby flooding?
Is the exhaust pipe leaky?
Did you heat cycle?
Do you warm up correctly?
Is the park brake on?

 

[Arnold]

Exactly what did u do in ur rebuild?

 

[gavinski]

bored out .10 new piston new rings new bearings new seals rebuilt the carb every thing is stock. I just don't get it

 

[Wifesblaster]

bored out .10 new piston new rings new bearings new seals rebuilt the carb every thing is stock. I just don't get it

So the engine and exhaust is 100% stock? Are you running the oil injection? If so what kind of oil are you using? If premixing, are you mixing 32:1? How did the reeds look? Is there a brass washer under the main jet?

 

[gavinski]

still running the injection sys yamalube two stroke oil reeds are good I don't remember if there is a washer under the main jet.

 

[Wifesblaster]

still running the injection sys yamalube two stroke oil reeds are good I don't remember if there is a washer under the main jet.

Please answer this question. Is the motor and exhaust completely stock?

 

[gavinski]

it only ran good once sisce I rebuilt the motor I installed a new coil ran it had plenty of power put it away and the next time I ran it, it was acting up again tried different coils and cdi boxes without any luck. I think it might me the magneto

 

[Wifesblaster]

Here is what comes to mind with those symptoms. Pull the flywheel again and check the woodruff key. Is the TORS removed?

 

[gavinski]

every thing is stock except the piston. stock exhaust, stock carb

 

[Wifesblaster]

Here is what comes to mind with those symptoms. Pull the flywheel again and check the woodruff key. Is the TORS removed?

Did you do the proper heat cycles? Did you leak test AFTER this problem occurred?

 

[gavinski]

tors is eliminated just had the flywheel off woodruff key is in place

 

[gavinski]

let it warm up till the muffler is warm to the touch. just did leak test two days ago been having the problem for months

 

[gavinski]

tomorrow night I will put the in line spark tester on in and see what the ignition is doing at full throttle

 

[Wifesblaster]

let it warm up till the muffler is warm to the touch. just did leak test two days ago been having the problem for months

When you rebuilt the motor did you have the cylinder bored/honed? I would do a compression test. If it passes a compression and leak test then it is pretty easy to figure out. You should see at least 120psi.

What does the spark plug look like? Fat blue spark when kicking it? What jets are in the carb? (you should have a 5j22 needle, 32.5 pilot, and 230 main) Was the float height set? Clip in the middle slot of the needle? Rubber gasket in carb cap? Does it smoke a lot?

Answer those questions and we should be able to narrow it down.

 

[Wifesblaster]

Sounds like you got some tools. Do a compression test and answer those questions and we should be able to get it purring like a kitten.

 

[gavinski]

had cylinder bored out by local machine shop.dosnt smoke a lot, I will have to pull the carb to check the jets and gaskets, plug looks good not fouled

 

[gavinski]

I will do a comp check tomorow