Box Stock

My predator is tweaking

Z

ztb

New member
Ok so i got this engine from a friend after he snapped a rocker pivot stud and didn’t want to work on it no more I got the broken bolt out and replaced it then I replaced the rockers and lashed the valves to spec with engine at top dead center and when I tried turning the engine over it had no compression so I checked the timing and it was on point so then I took the rocker arms off and pulled it and it had tons of compression so I know valve seats and rings are good so then I took off the exhaust rocker and over tightened the intake one until it had no compression then backed the pivot off slowly until I could pull the cord with compression then I did the same thing for the exhaust side and it ran good and idled fine and would rev up no problem but was running very rich (carb on this is non adjustable for some reason) and when I tried it ride the mini bike it would bog down under load after running it a while and checking clearance intake had absolutely 0 clearance and exhaust had .020” only thing I’ve done is governor delete and like I said carb is non adjustable
Any help would be appreciated
 
ztb said:
Ok so i got this engine from a friend after he snapped a rocker pivot stud and didn’t want to work on it no more I got the broken bolt out and replaced it then I replaced the rockers and lashed the valves to spec with engine at top dead center and when I tried turning the engine over it had no compression so I checked the timing and it was on point so then I took the rocker arms off and pulled it and it had tons of compression so I know valve seats and rings are good so then I took off the exhaust rocker and over tightened the intake one until it had no compression then backed the pivot off slowly until I could pull the cord with compression then I did the same thing for the exhaust side and it ran good and idled fine and would rev up no problem but was running very rich (carb on this is non adjustable for some reason) and when I tried it ride the mini bike it would bog down under load after running it a while and checking clearance intake had absolutely 0 clearance and exhaust had .020” only thing I’ve done is governor delete and like I said carb is non adjustable
Any help would be appreciated
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There is a compression release on the exhaust lobe of the cam that might be what’s aggravating you. I don’t set lash at TDC on these engines, I use 95 Shaws method of setting lash. Basically you set the lash on one valve while the other is open. Do a search about valve lash on here and you will see his method posted and reposted.
 
XXX#40 said:
In another 10 years, kids won't know how to hand write their own names.
I'm pretty bad, but man.......
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The local high school here that I graduated from 20 years ago don’t teach kids how to write checks anymore and the elementary school don’t teach cursive anymore. I’m sure they are getting plenty of propaganda shoved down there throats though…
 
Hobbs said:
The local high school here that I graduated from 20 years ago don’t teach kids how to write checks anymore and the elementary school don’t teach cursive anymore. I’m sure they are getting plenty of propaganda shoved down there throats though…
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These are the funniest posts. If you are picking on grammar and talking about graduating from high school, I think you meant, "doesn't" teach kids anymore......"

Our elementary schools in Western NY still teach cursive.
 
Arik434 said:
These are the funniest posts. If you are picking on grammar and talking about graduating from high school, I think you meant, "doesn't" teach kids anymore......"

Our elementary schools in Western NY still teach cursive.
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I never said anything about grammar. I also never said I was perfect. Maybe reading comprehension isn’t your thing. Recent graduate?
 
Ok. For starters set your valves using the ICE method. Spin your engine over clockwise until the exhaust valve starts to open and adjust your intake valve. Don’t be afraid to put some clearance in it. It won’t hurt it to be lashed a tad loose. After your intake valve is adjusted rotate your flywheel clockwise until the intake valve goes full open and just starts to close.. then adjust your exhaust valve.
 
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