Ghost in starter!

[Old Salt]

I own a F26ft hard top with a mercruiser engine and last spring i had to pull the engine to replace the oilpan and flywheel cover. While the engine was out i desided to replace the starter, the orignal starter (CW) was mounted ahead of the flywheel next to the oilpan. I replaced it with a starter (CCW) mounted on the bell housing, aft of the flywheel. To do so i had to replace the flywheel. After completing the work all went fine and i used the boat all sumer with no problems. This past winter the boat was laid up in dry storage for about 4mo. When i went to do the normal spring PM on the boat all went well until i tried to start the engine, due to the fact that the carb was dry of gas it didn't start right away. The starter ingaged as normal and i let the engine turn over for about 30sec and released the switch, the starter continued to run and i had to cut the main power switch to get it to stop. I started to troubleshoot the problem. I checked all the way to the starter, nothing wrong. I then engaged the starter and while it continued to run i removed the starter wire at the starter and the starter continued to run, cut power. Each time the power was turned off the bendix released, when power was restored to systen all was normal until i tried starting the engine again, same problem. I removed the starter and had it tested at a starter repair shop and no problems were found, worked fine. Reinstalled starter and same problem. When engine starts all is OK. If engine does not start right away starter will continue to run until either i cut power or engine starts.
Does anyone have any ideas as to the problem. Thanks All

[Paul]

Hey Old Salt,

When starter shops test these things, it's usually not under load like it is when it's actually cranking your engine. When actually cranking the engine, a lot of amps are drawn thru the relay contacts which, if rough, can cause them to stick. I'm assuming that your Mercruiser is a GM product and that you have a relay/solenoid combination mounted right on the starter. I would suggest changing this part and see if the problem goes away.

Hope this helps
Paul
Cruise Control
'78 F-26 HT

[Old Salt]

Paul
Thanks for the reply.
The engine is a GM350. The starter repair shop did test it under a noload condition, but they also dissemblied the solenoid. They told me that the contacts were in good condition. They went ahead and cleaned and polished the electrical contacts. They allowed me to watch this process.
Like you said if it continues i will try replacing the solenoid.

[Safari]

had the same problem with a crusader 454 - had the starter rebuilt twice -same thing. Finally one guy at the shop told me that there was a kit put out by GM to alleviate the problem - it consisted of some spacers. I applied the kit, and it resolved the problem by 75% - it would still occasionally hang. Not related to this problem, I replaced the gel batteries with AGM batteries - end of starter problem! I think the cure was a combination of the GM kit and the higher voltage/current from the new batteries. When I had rewired the boat, I may have skimped on the size of the batt cables (and starter wiring).

[bobber]

When you talked about cutting the main switches to cut power were you talking about the red keys in the cabin area behing the helm? If so what is the proper name for them and where can I find them, One was cracked and broke.