Valve Question

[rumplecat]

I have a single cylinder diesel genset that will not start. Turns over great but will not hit, it puts out a cloud of diesel vapor not smoke? I think one of the valves are stuck open? they seem to function perfectly when you turn the motor over but I can't actually see the valves move only the rocker arms and springs. How do I check the valves themselves without taking the head off???
Thanks,
James G.

 

[Jones]

Excessive valve to rocker clearance might show a valve stuck open. Especially if you can't see a valve spring and valve stem being compressed when turning the engine over. You could put a rag, or better yet slip a soda-pop can, over the open injector line to protect yourself from the diesel fuel spray and put your thumb over the hole in the head where the injector goes to see if you're getting compression, but a far better bet would be a DIESEL engine compression tester that'll handle pressures generated by the 22.5(?) to 1 compression ratios. If you're getting compression but it isn't enough to build cylinder temps to ignition levels, it isn't going to fire.

 

[rumplecat]

Tried the thumb over the injector hole, no compression at all!!!! The rockers and springs are moving up and down equal distances, I guess the only thing left are bad rings on the piston? I checked the only local diesel shop that looks at anything but trucks, they only want , a shop mininum of, $160 just to look at it.
James G.

 

[m35a2cowner]

compression

If you can find an engine manual or a knowledgeable individual check to see if there is a compression release on the motor that might be stuck or work in a fashion you are not familiar with. Some engines have a compression release which remains open until the cranking speed reaches a certain rpm. Check to see if for some reason there is a flapper or blockage in the intake or exhaust sides of the engine.
Good luck

 

[OPCOM]

RE: compression

What is the orange cap on the head? It looks military, what kind is it?

I have a small 2-cylinder air cooled diesel that has a lever on each head that holds the exhaust valve open for compression relief so the engine can be started by hand. Maybe that one has something like that.

 

[Jones]

RE: compression

I have some genset manuals. Let me know which model yours is and I'll see what I can turn up.

 

[rumplecat]

RE: compression

Someone on the forum earlier called it a MEP 13, I don't know if this is right or not? It has a Wisconsin-Robin 6 hp single cylinder diesel motor running a 3.1KW generator. The red cap covers a tube used to add fuel to prime the engine. Any help is appreciated.
James G.

 

[acetomatoco]

RE: compression

Is the "compression release" in the open position??

 

[Jones]

RE: compression

Couldn't find any MEP 13 stuff in my etm files. I did look over troubleshooting for my MEP016 and it looks like a lot of safeties are interconnected. Mine will shut down with low oil press. and gen faults. It also talks about checking to see if the governor linkage is free/not binding and if the fuel start solenoid is working properly. PM me with an address and I'll mail you copies of the troubleshooting pages.

 

[rumplecat]

RE: compression

I can't find a compression release anywhere on the genset. It has a on/off switch, run lever and a stop lever and that is about all, it is a very small and simple piece of equipment, but I still can't get it started!!!!!! Jones I will send you my address tonight or do you have it formated to email??
THanks,
James G.

 

[Jones]

RE: compression

Can scan the troubleshooting pages and email them but the manuals are too big to do that with. The engines on similar gensets in my ETMs are Yanmars or Onans. Have you thought about contacting Wisconsin Engines?

 

[winnona]

do a compression test first.