YM 1700 head gasket

[puresol]

It uses the front lobe on the cam? What exactly would I be looking for? Something didnt look right with the rockers in that area the night I removed the head, I believe it was there. Something in that area wasnt the same as the other three, it wasnt sitting at the "height" of everything else. Maybe I have a picture of the head I can look at.

 

[careyo63]

Someone's been in that motor!!!! Looking at the damaged to the Piston and from what I can tell from the Pic. of the Cyl. wear doesn't match the piston. I'd almost Bet money that Head wasn't Torgued Properly looking at the Carbon on both sides? The pics. are good and can be Deceiving so that's just IMHO.

 

[puresol]

No way I will ever know, but thats what I have been thinking. Im definately not the first in the last couple of years. Need to get it right this time. Still no word on the head from the shop.....Its driving me crazy.

 

[Car Doc]

Broken spring would be my guess as to the height comment.

 

[puresol]

Ok more pictures. At first I thought the cylinder head stud was put in upside down. Now Im not sure if its the right part. There are six on the block. One is obviously shorter, is the one on the left front suppose to be longer? In the parts drawing it looks longer, but those drawings can be deceiving. When I removed the head the whole thing unscrewed. You can see the height difference in one of the attached pictures.





I didnt notice last night but the top ring on that piston was broken. I feel lucky- guess I could have some serious problems.

 

[winston1]

The parts manual shows 4 studs with the same part number and 2 studs with differing part numbers. 3 different part numbers total. The one on the front left does show a quantity of one.

 

[puresol]

Thats good to know, thought I might have a problem. I have a shop manual, need to get a parts manual. Does anyone have a trick to cleaning threads in a situation like the head studs. I have been threading/ pushing a rag in and out.

 

[Car Doc]

When rings break they will wear the cyl walls something terrible and they also wear out the ring grooves in nothing flat so good thing you are putting new pistons in. The studs are different lengths on mine there is a step in one corner of my head so your stud arrangement is probably ok just guessing.

I use a tap and die if I can find one I have also taken a cutoff wheel and cut my own thread chasers out of bolts for bolt holes so as I dont take any metal out with a tap. If you have an extra bolt I could tell you how or post a pic but I doubt you will find one that size. A wire wheel is going to be the best thing just having clean threads is all you need an run a nut on and off several times.

Did you do any cleaning on that piston it looks awful shiny and nice? I am wondering if this engine was rebuilt and then severely overheated by the looks of the melted piston top above the top ring? just thinking out loud.

 

[puresol]

I got the stud bolt clean, problem is down in the hole. Will see what I can come up with. Dont think I am ready for a tap- never used on before- may not be the place to learn.
The piston is like it was when I pulled it out two nights ago. Didnt even wipe it down.
When I got the tractor none of the warning lights worked. I fixed them, then decided I didnt trust them, and put in gauges. I have a feeling that the "Gentleman" that sold me the tractor wasnt quite as forthcoming as I would have been. When I dropped the oil pan I could see marks where the oil pan gasket was scraped off. Im not sure how long those marks would last, but just reinforces my thought on someone being inside the motor recently.

 

[winston1]

Puresol, I sent you a pm.

 

[clemsonfor]

Maybe he was just doing as the manual says and droping the oil pan every 150 hours or whatever and cleaning/making sure the pump screen was clear!!

But i think the gasket scraping marks could be there for a long time if not indefinitly? I have pulled stuff that i was the last person in and could see signs of where i had done it before, weather it be old scrape marks bits of old gasket that were left or some other sign.

 

[puresol]

Still no word on the head- shop said it would be ready by the end of the week- they just didnt say which week.
How much play should I feel in the cam followers? Should I be able to push them up and down with my finger? What about wear on the followers? While I have the head and oil pan off is there anything else that needs or I should at least visually inspect?

 

[lmfrancois]

I have a Yanmar 1700 and as soon as i start it it, Coolant comes spewing out at a high rate of pressure. Is that a sign of a blown gasket?

 

[winston1]

I have a Yanmar 1700 and as soon as i start it it, Coolant comes spewing out at a high rate of pressure. Is that a sign of a blown gasket?

Yes. Welcome to the forum. :welcome:

 

[California]

I have a Yanmar 1700 and as soon as i start it it, Coolant comes spewing out at a high rate of pressure. Is that a sign of a blown gasket?

Also, be sure to use the compression release every time you crank it, to blow the water out of the cylinders before it starts. Water cannot be compressed and will break the rings.