Compression

[Merlin]

I just did a quick compression test on my 03 shee and it was at 125-128psi in both cylinders. I did the test cold. I have 2 questions.

1. Should I warm it up and do it again? Its pissing down rain form that storm.

2. I have a rm timing plate, if I go to +4 will I still be alright with pump gas?

 

BTW the motor is stock, with stock head and carbs.

Have FMF fatties with powercore 2, k&N filter etc, but that shouldn't mater with compression

 

Thanks

[yamaha04]

compression sounds good to me its only out by 3 psi and that could come back if warmed up. also your supose to do the test warmed up but i think i have heard it only goes acouple psi. if you advance your timing yes you will be able to run pump gas.

[David Keith]

Your compression is great. Let us know if you notice a significant change by advancing your timing.

[Merlin]

I just went back out and did another compression test after letting the bike warm up. After all was said and done, I checked it 4 times on each cylinder and I kept getting betwen 125-128 psi on both cylinders.

 

Is this bad? BTW I'm at sea level maybe 200 ft above

 

 

Your compression is great. Let us know if you notice a significant change by advancing your timing.

 

Are you referring to the compression after I install the timing plate or just how it runs?

[yamaha04]

I just went back out and did another compression test after letting the bike warm up. After all was said and done, I checked it 4 times on each cylinder and I kept getting betwen 125-128 psi on both cylinders.

 

Is this bad? BTW I'm at sea level maybe 200 ft above

Are you referring to the compression after I install the timing plate or just how it runs?

 

you compression is good. he was wanting you to let us know how your bike preformes after the timeing change.

[Animalman294]

You're in the balpark with the compression, and yes you can run pump gas clear up to about 150-155 psi and then go to 50/50. You really need to do plug chops and listen to your motor it will tell you everything.....................

[Merlin]

You're in the balpark with the compression, and yes you can run pump gas clear up to about 150-155 psi and then go to 50/50. You really need to do plug chops and listen to your motor it will tell you everything.....................

 

 

I don't believe there is anything wrong with my bike. Plugs are always a nice chocolate brown, motor sounds good. I have been doing lots of reading about the 93 octane and everything kept saying do a compression test to be sure. I wanted to make sure I could advance the timing and still have pump gas. Next I would like to lok into getting a NOSS head.

 

One other question, will I have to rejet if I advance the timing +4?

[yamaha04]

One other question, will I have to rejet if I advance the timing +4?

 

dont think so