120 lehman stop arm adjustment

Tator · 08-17-2019, 07:55 PM

For the 14 years I've owned our boat our port engine has taken awhile to start. The longer it sits without being run, the longer it takes to start-up to 30sec of cranking. Also, have to give it a lot of throttle if it's been sitting. Runs fine once it starts. I've checked numerous things over the years-timing, changed injectors, etc. Thought I would check the position of the stop arm but can't find the spec or a shop manual. Can anybody help?

Tator

Russell Clifton · 08-17-2019, 08:11 PM

Here's what the owner manual says about all the naturally aspirated engines:
Check that engine stop lever is fully towards the rear (flywheel end) of engine. Set throttle to 1/4 open and start engine. Adjust speed.

Could it be that the stop soleniod is not puling the lever all the way back?

psneeld · 08-17-2019, 08:12 PM

Just disconnect to troubleshoot.

Seriously doubt it's that...but check to eliminate... however may be the injection pump and that adjustment or rack movement could be an issue.

Tator · 08-17-2019, 08:48 PM

Quote:

Originally Posted by Russell Clifton

Here's what the owner manual says about all the naturally aspirated engines:
Check that engine stop lever is fully towards the rear (flywheel end) of engine. Set throttle to 1/4 open and start engine. Adjust speed.

Could it be that the stop soleniod is not puling the lever all the way back?

My stop solenoid pulls the rod forward to stop the flow of fuel. When not activated, it goes to the rear. If I remove the arm, the lever on the pump will go back at least another inch. The rod is threaded for adjustment. I just need the specs or parameters.

tator

psneeld · 08-17-2019, 08:54 PM

I think it would be full throw in either direction.

Disconnect and see if the start improves.

Redhook98 · 12-03-2020, 08:32 AM

I had this same issue. My stbd motor was rebuilt by the PO. Injection pump was also rebuilt when he had a hard time starting it after the rebuild. He subsequently replaced almost everything on the motor trying to get it to start like normal. When warm, it would start right up with no issues. When cold, it was horrible. 45-60 seconds of cranking to do anything (not all at one time). And when it did start, the RPMS would cycle up and down about 400-500 rpmps until warmer. Brian at AD recommended throwing a set of block heaters in my motors and not worry about it if it started so well when warm.

After reading this thread late last year, I looked at my adjustment. Turned the adjustment further out about 5-6 turns and it started right up. No issues at all. I ended up taking about 8-10 more turns out of the adjustment and now it starts as soon as I hit the starter button, even in winter. Just don't adjust so far that the solenoid does not kill the motor when needed.

The PO literally slapped his forehead when I told him that. I think this is an adjustment that not many think of, or even know exists.