soft seize?

[iceman77]

I think i might have had a soft seize today. i was riding around for about 30 min or so and then my bike cut off. i tried to start her but she wouldn't turn over. when i kicked started her she turned over then i was able to start her.
before this happened my compression was 142 now it is 115.
what do you guys think?


thanks:
TJ

[Dio89Elite]

It could very well be a soft seize. Did you try to re-start it? Soft seizes will usually restart after a cool down period. Be sure to look for the reason for the soft seize and take care of it. Not much fun to ride and stop. Let cool down. Restart (and repeat from ride and stop).

For my particular case, my coil started going bad. You may want to check this too.

[Wheelman-111]

Greetings:

If your compression dropped 30PSI, it's more than a soft seize. Time to dismantle and inspect, then find the reason.

[iceman77]

Greetings:

If your compression dropped 30PSI, it's more than a soft seize. Time to dismantle and inspect, then find the reason.

i took everything apart after the compression test. rings, piston, and jug all look good. any suggestions on why the compression might have dropped so much?

[motormike]

Your loss of 30 psi mysterious....rings and gaskets are the first two logical suspects.
I believe I would check cylinder with micrometer to establish condition of bore, as well, check piston with guage. ?

[Wheelman-111]

Greetings:

I suggest you reicheck the compression holding the throttle wide open.
If it's the same, and you're sure of the 142 before, suspect a crank seal, bad reed, or gaskets as Mike said.
I bet the crank seal because it was sudden. The vac leak and lean-out could've caused the overheat and seize, too.

[iceman77]

Greetings:

I suggest you reicheck the compression holding the throttle wide open.
If it's the same, and you're sure of the 142 before, suspect a crank seal, bad reed, or gaskets as Mike said.
I bet the crank seal because it was sudden. The vac leak and lean-out could've caused the overheat and seize, too.

positive on the 142 b/c i checked it three times b/c i thought it was a little high. i've never done a compression check w/ the throttle wide open. what does this do?


Thanks:
TJ

[Bear45-70]

Greetings:

I suggest you reicheck the compression holding the throttle wide open.
If it's the same, and you're sure of the 142 before, suspect a crank seal, bad reed, or gaskets as Mike said.
I bet the crank seal because it was sudden. The vac leak and lean-out could've caused the overheat and seize, too.

positive on the 142 b/c i checked it three times b/c i thought it was a little high. i've never done a compression check w/ the throttle wide open. what does this do?


Thanks:
TJ

Always do a compression check with throttle at WOT. Gives you a more accurate and consistent reading.

[Wheelman-111]

Greetings:

If less air gets in, there's less to compress.
Removing the carb altogether is even better.

Bad reed or seals let air out =
less air.

[iceman77]

Always do a compression check with throttle at WOT. Gives you a more accurate and consistent reading.

got ya. thanks for the info. will it be a lower reading when doing it at wot?



TJ

[Bear45-70]

Always do a compression check with throttle at WOT. Gives you a more accurate and consistent reading.

got ya. thanks for the info. will it be a lower reading when doing it at wot?



TJ

Almost always higher.

[iceman77]

Almost always higher.

dang. so my 142 from before would've been to high if i would have done the check at wot.

TJ

[Bear45-70]

Almost always higher.

dang. so my 142 from before would've been to high if i would have done the check at wot.

TJ

Yes.

[iceman77]

well crap... mybe i should just put the stock bore back on.


TJ

[motormike]

....I understand how a crank seal will lean the mix....How does a crank seal reduce compression ?......