YM1700 injector timing question

[careyo63]

I forgot that video that looked as if you F'd up some pistons also ? UTDA Bjob?

 

[goose117]

Update - I noticed a small puff of smoke coming from the bottom of the head when trying to start so pulled the head. The head gasket - which I had just installed a week ago - had a large piece missing. Going to clean the surfaces again and put a new gasket on.

 

[winston1]

Did you check your head for warpage?

 

[thepumpguysc]

Or injectors for spray pattern.??

 

[ponytug]

Or injectors for spray pattern.??

@goose117 posted a nice video early in the thread. It looks ok to me.

All the best,

Peter

 

[bmaverick]

Update - I noticed a small puff of smoke coming from the bottom of the head when trying to start so pulled the head. The head gasket - which I had just installed a week ago - had a large piece missing. Going to clean the surfaces again and put a new gasket on.

When you put the head back on,
- never slide the head around atop the gasket.
- place all bolts in first as 'finger' tight.
- there is a bolt sequence and several torque down levels to run-down
- between each torque levels, pause for 15 to 30mins to let it take a set
- At final torque sequence, do not turn torque wrench fast, go SLOW.
NEVER use clicker torque wrench on the FINAL torquing. Clickers can exceed the max limits or fail to properly hit the values.
A Dial torque wrench is typical for engine head work.

As for the gasket, there are many CHEAP ones out there in material and quality. Not certain if the gasket was the problem.

Is it possible the piston or other item caught the gasket and ripped it?

This Yanmar site has some helps,

How to Replace a Blown Head Gasket | Yanmar Tractor Store

www.yanmartractorstore.com

 

[goose117]

Thanks for the suggestions. I will follow the installation instructions more carefully and also try the dial rather than click torque wrench. I also have a digital readout available.

There seems to be two kinds of gaskets that are available. All metal ones like the one I just pulled off and others that seem to be a sort of grey composite with copper rings for the seal areas. Sometimes I receive the composite and sometimes the metal gasket regardless of what the photo shows.

The head is new but I will check for flatness. I have checked the block before but not recently so I will look again.

Interestingly the forward pre combustion chamber nozzle holes for the front cylinder got enlarged but the rear one did not.

I don't see any indication that the piston somehow ripped this gasket but I was surprised by how damaged it is.