Top end rebuild Yanmar 1gm

[Casagf66]

looking for some pointers, pulling the motor out of my 27 foot mirage this week. It seems very straightforward just as long as all of the bolts break free. She only weighs 120 pounds so hiking her up and out shouldn't be too hard either. Do you guys have any recommendations for labeling and marking off things before and while removing the motor.

I purchased a brand-new top end, new piston and rings for $500.

Luckily my neighbor is a diesel mechanic and he will be doing the work with me.

I am going through with this work because after much trouble shooting we have found out that the motor has very low compression and will not start. I will also have to have a diesel mechanic look at the injection pump and governor as both the Ideal limiter and injecter limiter were tampered with as there is no longer a wire seal on them.

If anyone has done this before please share your recommendations, ups and downs

I'm particularly interested in tricks for keeping the alignment of the motor in tact for reinstall.

And I am also concerned about getting the governor and limiters back in order.

Hopefully this will do the trick and I'll have an almost brand-new motor again.

Cheers,

 

[Charles Erwin]

Consult Yanmar manual on this build. You mention top end only but you say you have piston too suggesting you intend to install same. Disassemble mic the bore and all other -- and don't assume a simple disassemble/reassemble will solve all ills You need measurements before you decide your final strategy.

Charles

 

[Benny17441]

It looks like you are on the right track. Remember the transmission has as many hours of use as the engine so taking the time and effort to inspect it and replace any worn components might be in order. I'm sorry but it will likely be impossible to keep the alignment of the engine intact; more than likely you will need new motor mounts ( don't go by that they may look fine) and will require to align the engine anew. I understand that you are just looking at a mere top end rebuild to get the engine running but to go through the trouble of removing and reinstalling the engine and not taking care of some of the other components that would be better accessible at this time may bite you back in the near future. Good luck.

 

[Bill Roosa]

an old trick we use in auto mechanics is to not clean the parts so you can see where the washers/nuts/bolt heads left a mark on the sheet metal/plastic and get the alignment back to the original. FWIW

 

[Captn Scotty]

Take you're injector pump and injectors to a specialist and have them re vamped, thats what the mechanic will likely do, and get the valves done too, if possible?

 

[lehighsail]

Take lots of pix as you go and copious written notes on copies of pages of the manual. If appropriate, put a ruler in the picture to give perspective. They can come in very handy on any engine project. Like is often said here, "don't ask me how I know".