Yanmar Starting problems

[John Conarroe]

I have a Yanmar YSM12 which has not been run in a number. I had the head redone with new valves, guides and seats. New head gasket and re torqued, valves set properly. It cranks but won't kick over. New filters and fresh fuel were also used. Any suggestions would be greatly appreciated.

 

[Steve Dion]

W.O.T.

John:1. Make sure that the fuel system has been bled of all air.2. Try opening the throttle to wide open. If the engine starts, back off as it picks up rpms. 3. Call the mechanic.

 

[Patrick Ewing]

Exhaust

Check the exhaust riser loop where the water is injected. Ours took us three days to figure out It was completely blocked with rust and soot and stopped the engine from starting.It is held onto our engine with 4 bolts and clamped to the exhaust hose. Take it off carefully and you won't need a new gasket.Good luck,Patrick

 

[Don Riha]

Injector?

Several years ago my 30 was very difficult to start, sometimes in would not. Turned out to be a "o" ring in the injector that would let the air out on the compression stroke. The second mechanic found it, the first didn't and just changed filters, etc.

 

[terry d]

same deal

Just rebuilt me yse 12 this augustI can think of several reasons that you have the problem _ if you have the maintenance manual pay attention to the governor adjustment and proper purge and timing procedures. I elected to replace the injector pump and injector, which in a 12 are very low cost items (about 150.00 for both parts) The Several Reasons1_ pay close attention to the placement of the compression release shaft when you install the valve cover_ I noticed you can actually position it in a fashion to hold the exhaust valve open w/o engaging the compression release lever2_ get a wrench and crank it over by hand (fuel line between the injector pump to injector mustbe disconnected ) and see if you can feel the compression build on the compression stroke3_ if you can feel the compression (and if your valves are set right you will) turn the engine by hand until you have fuel coming out of the fuel line. I actually expect that injection pump is the problem so if you don't get fuel pulses _ look there.4_ when they did the head, they had to remove the injector. There is a whole series of seals and washers that need to be in tact to allow for proper seal and operation of the swirl chamber. U may find that there is an air leak in this area.If you don't have the manual feel free to get back with me and I will send you the cut view of this assemblydornan_esd@ameritech.net