Low Compression? Vitos Big Bore

[teesee150]

I just picked up a 1995 Blaster with a supposed Vitos Big Bore 240 kit in it. I've been riding it, but was having problems with the low end and then it not running at all (no spark). So I replaced the coil (spark plug boot was reading 20 megaohms and primary coil was reading high also)), and the coils on the stator (the source coil was bad), and installed a Ricks Motorsports Electronic CDI unit. Now the low end is great and it starts much better. While I had it apart, I checked the compression and it only came up with about 32 psi.

Will the engine even run with only 32 psi of compression or is there a chance that my compression tester is bad? When I was replacing the coils on the stator, I was able to grab the flywheel and turn the engine over by hand with not a lot of effort. This is my first experience with a quad and a small engine, so not quite sure what to expect.

But after reading on the forums, it seems like the blaster should wheelie no problem, and I can only get it to the pop the front wheels if I dump the clutch. Seems like I should be able to just hit the gas and lift the tires, especially with the Vitos Big Bore. It also has a FMF pipe and Pro Circuit Silencer and a +3" swing arm.

I checked the spark plug, and the color looks good, so I assume my jetting/carb is correct.

 

[Blaster200boy]

I just picked up a 1995 Blaster with a supposed Vitos Big Bore 240 kit in it. I've been riding it, but was having problems with the low end and then it not running at all (no spark). So I replaced the coil (spark plug boot was reading 20 megaohms and primary coil was reading high also)), and the coils on the stator (the source coil was bad), and installed a Ricks Motorsports Electronic CDI unit. Now the low end is great and it starts much better. While I had it apart, I checked the compression and it only came up with about 32 psi.

Will the engine even run with only 32 psi of compression or is there a chance that my compression tester is bad? When I was replacing the coils on the stator, I was able to grab the flywheel and turn the engine over by hand with not a lot of effort. This is my first experience with a quad and a small engine, so not quite sure what to expect.

But after reading on the forums, it seems like the blaster should wheelie no problem, and I can only get it to the pop the front wheels if I dump the clutch. Seems like I should be able to just hit the gas and lift the tires, especially with the Vitos Big Bore. It also has a FMF pipe and Pro Circuit Silencer and a +3" swing arm.

I checked the spark plug, and the color looks good, so I assume my jetting/carb is correct.

Try a different compression tester. another reason why its hard to pop a wheelie cause you have that +3" swingarm.

 

[blasterdude14]

well the extended swinger has a factor in the wheelie ability. and to see if your compression tester is right or wrong try pusing down on the kickstart with your hand if it goes down with little to no resitance your compression is bad.

 

[teesee150]

well the extended swinger has a factor in the wheelie ability. and to see if your compression tester is right or wrong try pusing down on the kickstart with your hand if it goes down with little to no resitance your compression is bad.

I can turn the motor over pretty easily by grabbing the flywheel/magneto. It's also fairly easy with to do with the kickstart. But would the motor even run reliably with only 32psi of compression? I had turned the motor over several times in quick succession to get that number.

 

[blasterdude14]

if it can even run with 32psi it would be lacking power completly. if it can run with that low of a compression then im clueless

 

[Roccdeezy]

does your cylinder look aftermarket or does it match the head?

 

[justtwistit]

u have to have at least 120psi

 

[245stroker]

how did you do the comp test? did you hold the throttle wide open and kick it til the needle stopped climbing on the comp tester? the motor shouldn't even run with only 32 psi

 

[REEDracing94]

ive had them run at 90 psi and after that they quit so strokers right they shouldnt run that low

 

[ruthless_one3k]

^^^me too .

 

[Roostinshee]

Compression test before or after allowing it to run to operating temp? One of the o-rings broken on the spark plug adapter section? As the others said shouldn't even run w/ that low of a compression reading.

 

[CHutzell]

are you kicking it over until the guage stops?It sounds like you may have just kicked it over once

 

[blasterfreek30]

yup kick it till the needle stops moving on the gauge