YSM12 condition

Status
Not open for further replies.
Jul 22, 2006
73
S2 9.2A Battleship Cove
In case you haven't already pieced my story together from previous posts, we bought a '78 9.2A mid-season this year. We enjoyed it to the max for the last 1/2 of the season.
One of the quirks I had to deal with was the little YSM12 diesel. Raw water cooled and as simple as a lawn mower engine. I had trouble initially with air building up in the fuel lines. After changing the filters it ran fine until our last trip out, when I had to bleed the lines again. I'm not too concerned about it though.
However, what does concern me is how much it takes to get the little bugger running. Even in warm weather, it took the power of both batteries to get it to turn over fast enough to catch and even then she seemed to just barely putt to life after a good cranking. When I ran the motor to flush it out a couple weeks ago 45 degrees out) I needed to use a little squirt of starter fluid to get it to fire.
So my question is, is the cranking speed and startup normal for these primitive little motors, or do you think I rings? Ideally I would refit a newer, bigger motor but budget dictates I work with what I got.
 

BobM

.
Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
If you have a compression release rig a line from it to the cockpit locker. Open it to release compression and spin the engine up. After the engine is really spinning let the release go for easier starting. It may also be worth adjusting your valves. If they are even slightly off you are trying to start with reduced compression. A pro is likely worth the money for this. A friend of mine rebuilt his engine and fought to get it running properly. The problem was ultimately the timing.
 
Status
Not open for further replies.