compression test on atc 350x

[ustin666]

i did a compression test on my 86 atc 350x and it was 100psi is that to low???

[RodKnockRacing]

yes it should be about 175 psi

[WilliamJ]

Was that done motor cold or hot? Did you have the throttle wide open?

When the motor's warm and you have checked the compression, squirt a little oil into the plug hole and test again. If the pressure jumps up it points to the rings / bore being worn. If not it's more likely the valves. (Could also be the head gasket).

[TatTooL23]

Also make sure u unhook the decompressor. Seems like u didn't do that. I just did mine and it tested at 174. Let it idle for awhile or drive it around a bit to warm it up.

[ustin666]

i had my throttle wide open and my engine was cold.

[WilliamJ]

Okay, you should really test the compression with a warm engine as Tattool's post. That said, you don't get an increase from 100 to 175 psi - cold to warm. Check that you have got some clearance at the valves as well.

If with a warm engine, correct valve clearances, you can't get the compression over 150 then you'll need to strip it. If the squirt of oil puts the pressure right up it usually needs rings and a bore hone as a minimum.

[ustin666]

i was looking at the 452 sleeve. http://kustom-kraft.com/hondakits.html

[ustin666]

i did a new compression test and it was 120psi dis time. i disconnected the decompress er and wormed up my engine.I am going to adjust my timing because I know it is of a Little bit off.