Help needed

[Quingquad]

I rebuilt the engine on my blaster. New bottom and top end... I ran it for the first time this weekend and something seems to be off. When it runs it feels like somethng boggs it down, or like it's hitting some type of resistance. It shifts from 1st to 6th with no problems. Could it be something on the transmission side trying to seize the engine? Could it be related to the new piston and rings setting in? The carb has been sticking also, could this have anything to do with it?

Thanks for teh help!

 

[Surfrjag]

sounds like a jetting issue. fix the carb and do plug chop. have you adjusted your air screw at all? might also try a compression test and leakdown test just for peice of mind.

 

[hudack]

if your asking if it has to do with the rings setting im asumng you didnt break the motor in???

 

[Quingquad]

if your asking if it has to do with the rings setting im asumng you didnt break the motor in???

Depends on what the definition of break in is

I didn't race it on the first run bud drove it as usual.....

 

[Quingquad]

sounds like a jetting issue. fix the carb and do plug chop. have you adjusted your air screw at all? might also try a compression test and leakdown test just for peice of mind.

Can you tell me more about jetting issues? Why would this give a feeling of resistence vs. loss of power?

I appreciate the help!

 

[Blaster200boy]

Can you tell me more about jetting issues? Why would this give a feeling of resistence vs. loss of power?

I appreciate the help!

What are all the engine/intake/exhaust mods on your blaster? that includes Exhaust Pipe, air filter, airbox, carburetor, bore (motor), crankshaft.

 

[Surfrjag]

is it making any weird noise or anything? chances are its not a resistance but its just bogging due to a fueling issue. is your air filter clean and good sparkplug lets hear what mods and everything are done and what carb and jet your running. might wanna take and clean your carb real good also and see if that helps. have you done a leakdown test? they are recomended for any rebuild as an airleak will blow that thing up in no time.

 

[Quingquad]

is it making any weird noise or anything? chances are its not a resistance but its just bogging due to a fueling issue. is your air filter clean and good sparkplug lets hear what mods and everything are done and what carb and jet your running. might wanna take and clean your carb real good also and see if that helps. have you done a leakdown test? they are recomended for any rebuild as an airleak will blow that thing up in no time.

As far as mods is concerned, It's all stock with the exeption of a cilinder that has been bored 5x over. I also did some cleaning to the fuel ports and exhaust as Ken O shows on his videos.

Spark plug is new, and the air filter was cleaned. The carb is a stock Mikuni, and I am not positive on the jetting. Same as before the rebuild ...
I tested compression before running and it was at around 150. Past that I have not tried to leakdown test.

What should be my first step?

 

[hudack]

first step would be compresion test if you rode it how you noramly do thats a problem. you need to break the motor in before you beat on it and then if u opened up the ports that would need some rejeting. then if you didnt leakdown test you could have an air leak causeing it to lean out.
all these facotrs could add up to frying your new topend.
sounds to me like a jetting problem though do a compresion test then report back then i say we could go from there

 

[Quingquad]

Did a compression test. Read 140... I also removed the air filter to see the carb slide and found no issues. Having that said I am not sure what could have caused the revs to go so high erratically. If not the slide can that be jetting? I'm lost...

 

[scotj77]

contact holeshotman. he is a member here and he will sell you a leakdown tester for a great price. that is where you need to start. this test has nothing to do with compression

 

[darederek]

yeah sounds like an airleak. you really should have followed break in procedures that is going to come back and bite you

 

[hudack]

well thats an air leak and il bet money on it you need to get that worked out before you run it again

 

[Blaster200boy]

Did you take actual metal out of the cylinder? or did you just clean out the carbon. If you decided to cut metal out of the cylinder, it is going to be rejetted. if you cleaned up the carbon, you dont need to rejet.

 

[Larry's Shee]

Did you champher the exhaust and transfer ports properly?

 

[Quingquad]

I cleaned carbon deposits from the exhaust and smoothed port surfaces. If I shaved any cilinder material on the exhaust side it was not intended and should be minimal.

What is the proper engine break in procedure? What could I have damaged from not braking the engine properly?

What are the most common places for air leaks?


I appreciate everyone's feedback.

 

[liljatownboy]

are your carrier bearings good? does it roll easy in neutral?

 

[hudack]

intake the base gasket and the head gasket are most common you could have damaged your rings by not breaking it in you have an air leak like i said id beat money on it. get a leak down test or build one building one would be the cheapest way to go about it theres a diy on how to build it. if it doesnt hold air then start spraying all places with soapy water and look for bubbles if you find none around the gasket spray tyhe case halves and if nothing there time to spray the crank seals.

 

[Quingquad]

The bikes rolls easy on neutral....

I'm getting a leakdown tester from a friend. I'll report results as soon as possible. Thanks for the help!