Topic: Broken compression release

[Old Goat]

On my new mower, its a mod-x or CP, I have a 28 OHV single. It has the ARC flywheel, Denso starter, Precision cam & the ARC brass weights on a flattie crank. I probably ran it for about 15 minutes, total time, the other day until it broke a rocker. I replaced it, but when I revved it up it vibrated pretty bad. George told me to pull it back apart and check my brass weights, to see if they came loose. They were fine, but my compression release on the cam was broken. The halfmoon shaped weight was broken off close to the pivot pin. It looked like when the motor started and the weight flew out it was hitting the brass weight on the crank and thats what broke it off. The spring on the compression release was holding the pin with the round side out, so the lifter was opening the intake valve every compression stroke, even after it was running. I think thats why it was vibrating when I revved it up. I removed the complete compression release assembly and put it back together. It starts when it's cold, but I don't know if it will after it gets hot, I didn't get a chance to run it yet. Did anyone else ever try that, or has anyone ever had the compression release hit the brass counter weight?

[George Herrin]

If using a modifed cam I remove the compression release completely. My sportsman is built to the hilt (still a 28) and billet wheel too, but it uses a stock Starter. Starts fine. I do have to roll it backwards with the stock starter so it will get a running start on the compression storke. But the point is it starts fine cold or hot.

[Old Goat]

OK. Thanks, George. I'm gonna try it that way too.

[amcchevy1]

i have a 31" ohv with, we'll say, head work. when i put the cam in, i removed the release altogether. same as George, i "rewind" it before every start. i starts fine that way. it will not start if it is on compression stroke.

[Old Goat]

OK. Thanks amcchevy. That's what I'm gonna do, too. When you did your head work did you fill in the corners where the valve journals end with JB Weld?

[amcchevy1]

its actually a 21" head with mild porting, it has the wedge lock keepers instead of the clip style. i didnt fill in anything on those heads.