Won't Spin Past Compression Stroke

[andy spence]

This is something that happens a lot with these Briggs engines. I have repaired several with a way that a lot of the hard core mechanics will disagree with but add a set screw in the spot where the compression release lever rests until it starts. It is just like the camshafts were back in the day when Briggs advertised their Easy spin starting. It is just a small lump on the intake valve to release the compression when starting. Works the same as the existing lever as the set screw is rounded and only protrudes .013 of an inch so that it does not affect the running of the engine but solves the problem with the starting using a 25 cent screw and a little time since the engine has to be removed anyway. Agree or not, just food for the thought but it works for me with no complications.

 

[LMPPLUS]

Model 33R777
Type 0003 G1
Code 190214ZD
Single cylinder.

Will not spin past compression stroke.
Battery measures 12.8 v. Starter is new (and all this was tried with 2 used starters as well, so 3 different starters).
Battery connections cleaned, starter relay connections cleaned.
Battery voltage measures 12.7 all the way to the starter; battery, starter relay input, starter relay output, starter lug.
Remover spark plug, spins like crazy.
Attached car battery. Will not spin past compression stroke. Remove spark plug. Spins like crazy.
Attach compression gauge, struggles with partial spins, but got 100 psi , so it may register more if the engine could spin enough to give a good test.
So, why, if all parameters measure good, will the starter not get past compression?
Thank you,'
J

Sorry if this has already been said, but you have compression issue trying readjusting the valves if that doesn't work you probably have a bad camshaft that's not working the decompression release. Good luck.

 

[RevB]

Why does a compression release exist? For the weak human pulling the cord. No engine equipped with a starter should ever require a compression release.

And no amount of adjustment of the valves will fix a worn compression release cam lobe. Drain your oil and look for sparklies. May be worse than you think.