predator 6.5 low compression?

[ngtcrlr1964]

I took carb apart to clean out, then decided to pull srark plug and check eng comp. It only hit 65lbs? isn't that kinda low? I also tried a few drops of oil in cyl and retried comp test, same result. valves bad maybe. just wondering.

 

[landuse]

I took carb apart to clean out, then decided to pull srark plug and check eng comp. It only hit 65lbs? isn't that kinda low? I also tried a few drops of oil in cyl and retried comp test, same result. valves bad maybe. just wondering.

Have you done anything else to the engine? Remember that these engines have a compression release valve. There is some way to check the compression by turning the flywheel the other way?? One of the other members will know exactly how to do it

 

[Russ2251]

When engine is spun, does it have a tendency to "bounce off" the compression cycle...or is it mushy?
How many hours on engine?
Any difficulty in cold starting?
A few small engine manufacturers post the compression numbers (PSI) in their specs, most do not.
For my engines, which do not have a mechanical compression realease, compression should be approximately 115 psi. The minimum serviceable limit is 80 psi.

 

[ngtcrlr1964]

Don't know how many hrs on motor,just bought used kart this past wknd. It seems to be all stock (6.5 predator). Didn't know about the compression release on these! Haha ,will look into. Is this motor also known as "clone" ? Noticed this in some of the parts suppliers listings. Spark plug gap was only set at 10 also.too small? Thanks guys...

 

[mckutzy]

About 30-35 is a proper gap to run stock.
Compression release is done on the cam itself.

 

[el camino boy]

no not the valves

I took carb apart to clean out, then decided to pull srark plug and check eng comp. It only hit 65lbs? isn't that kinda low? I also tried a few drops of oil in cyl and retried comp test, same result. valves bad maybe. just wondering.[/QUO


no i don't thank that it is the valves. take the plug out, put your thumb over the spark plug hole pull the pull string if your themb moves up and down then you have nothing to worrie about

 

[ngtcrlr1964]

Thanks for all the info guys. (

 

[Axx3d]

If she's still running strong and holds an idle i wouldn't worry about it.

 

[ngtcrlr1964]

yup, she runs good now... since the carb, fuel tank and gas line has been properly cleaned out. next on the to-do list: inspect torque converter. The driver part was worn out, one spring all stretched out? ahhhh

 

[sied_wayz]

Was that a wet or dry compression?

 

[ngtcrlr1964]

Did both. However upon further info I found out it has compression release. So I guess it dosent matter ...wet/dry. need to do a reverse spin comp test, so ive been told?