Compression release

[Beltrack]

Do all model 70s have compression release?

 

[kharvey]

I don think any of the 7 HP engines had compression release, unless it has a blown head gasket.

 

[Beltrack]

Well then, mine needs one. I’ve rebuilt the S/G, retarded the timing, used ethanol free high octane fuel. Nothing helps. I’ve read about the CR in some Kohlers and that a spring can break causing the CR not to function. I’m grasping at straws.

 

[lpalma]

good reading.

 

[Beltrack]

good reading.

Thank you. Page 33 +/- shows the spring for the CR. I’m thinking mine is missing/broken.

 

[jdrong]

Make sure you need a new spring before completely disassembling the engine. Do a compression check first. there should be little or no compression. On my 149 I discovered the weights have stuck or jammed somehow in the past and I have removed the cam gear cover and lightly tapped the weights to get them working again. I've read the tab that keeps the valve slightly open can bend or wear just enough to not open the valve. it can also break off.

 

[mgonitzke]

The parts manual for the 70/100 only shows the spark advance cam, not the ACR version. You should be able to verify which kind it is by pulling the engine and removing the oil pan.

 

[Beltrack]

The parts manual for the 70/100 only shows the spark advance cam, not the ACR version. You should be able to verify which kind it is by pulling the engine and removing the oil pan.

Good advice from both. Thanks. I’ll do a compression check, but I’m pretty sure it’s got plenty judging by the way it resists the starter. I even reduced the point gap to 14 thinking that the timing was too far advanced. It made no difference. I now have it back at 20 and it is spot on when checked with a timing light.