um, if my engine sounds like a 4-stroke dirt bike and won't idle, is it blown?



I just made a balls to the walls run last night and it did fine, but then lost ALL oil prissure when I turned into the driveway, it has oil, I checked, but this morning when I cranked it, it didn't want to start, so I gave it a little gas and it fired up but is running rough as hell, and when you rev it it sounds like the 4 stroke, like pulsing instead of smooth, I wish I could just post a vid, but I don't have a site to host it.

oh yea, 1990 small streetport vert, still n/a

mybe its your exaust!

Those sound like the symptoms, but do a compression check to be sure. You can do a compression check by ear too, just crank the engine by 1/2 revolutions with a 19mm socket on the main pulley. Make 3 complete revolutions to here each " swoosh " stopping each time at a half revolution to hear 1 swoosh, you should here 6 of them. If an apex seal let loose you would hear only 4. They should all be uniform in loudness.

I believe a 4 stroke dirtbike sounds normal, perhaps you'r talknig about a 2stroke dirtbike which sounds awkward and changes pitch constantly.



kevin.

um if you have the tranny off how easy should it be to turn the motor over with the flywheel? I can just put my finger on it and spin it https://www.nopistons.com/forums/pub...DIR#>/ohmy.png

That would be a bad thing...

yea im gonna have to go with camel on this one, thats a very bad thing.



kevin.

I just tried to start it again, I can't even hear that thump thump sound it used to make when it was turning over, the starter is just spinning the crap out ov the engine, it doesn't sound like there's any compression. and Its not the exhaust, the exhaust has been on there for months and its always been loud but its not the noise, its the way it pulses, like a one cyl. errrr. dammit



and I didn't mean like fling it and it keeps spinning but like you can put your finger on it and turn it over easily.

Yea thats really bad, its rebuild time.