I was Bored so Pulled the Head on my Yanmar

[Group9]

Originally Posted by ohdrinkboy

i'm in awe of sailorchic

Please don't tell me she can back a trailer, too.

[belizesailor]

Originally Posted by Group9

Please don't tell me she can back a trailer, too.

Judging from her other posts she knows lots of other boat stuff too.

Wow, what a woman...please post pictures of toolbox. ; )

[Krogensailor]

Originally Posted by Navatech

What you SHOULD have done is do a compression test BEFORE pulling the head...

I agree. And I'm sure you know that when doing the compression test, if a cyclinder show low you can repeat the test by adding a squirt of oil in the cylinder. If the pressure rises, I get this backwards sometime's, if it rises it indicate rings and if it stays the same it indicates valve problems. Also you can't check for flatness of a surface with an aluminum ext. You'll need a machinist straight edge. Lastly, I have a VW pathfinder and it is a zero clearence engine. The head can not be decked. Good luck

[sailorchic34]

Well, last night I added oil (1/3 cup) to all three cylinders. This morning #1 and #2 are basically unchanged. #3 is almost empty. Now #1 was the cylinder with the relatively heavy carbon buildup. #2 looks new, and top of #3 was black with tan buildup in a few places, So #3 looks like bad/broken rings. I'll probably check #1 too while its out. Guess what I'll be doing this next week.

Yes, If I had money, I would have hired a mechanic to do a compression test, or purchased a diesel compression tester. But I barely have money for ANY parts, let alone a $200+ compression tester. So I make do.

HAHAHA tool box.. I have a canvas tool bag with sockets and such, a west marine tote bag for bigger things. I also keep a small set of metric sockets and a set of metric wrenches, each in their own zip lock bag, next to the engine.

While I have backed a trailer in the past, lets just say that straight line backing is highly over rated.

[Krogensailor]

Having read some of your post's in the past, I'm sure you'll get it done.

[Cheechako]

Just a reminder about my post ages ago: My 3GM30 was hard starting, although ran well at crusing speed......... and had a broken ring land on one piston. Cant see it without pulling the piston unfortunately.... unless it starts eating into the cylider wall...

[sailorchic34]

Originally Posted by Cheechako

Just a reminder about my post ages ago: My 3GM30 was hard starting, although ran well at crusing speed......... and had a broken ring land on one piston. Cant see it without pulling the piston unfortunately.... unless it starts eating into the cylider wall...

I remember that. Figure I'll be pulling the engine and pistons. Cylinder walls look ok, That is no wear marks and zero ridge at top of cylinders. Though I need to find someone with a micrometer.

[sailorchic34]

Oh Groovy..... So noticed finally that I have grooves in #3 cylinder at 3 and 9 o-clock (12 noon facing the front of the engine. The groove at 3 oclock is thin but I can just catch a knife blade edge on it. At 9 oclock there are two grooves shallow but wide (1/8" ish) and at the top there is a horizontal lip about an inch long about 3/4" down from the top. I can just feel it with my fingers. Pretty much all the grooves stop about 3/4 inch down. There are a few other very light grooves at 10 oclock that can't be felt.

So It's looking like a broken ring or land or something. so happy... not. Doing small things today, disconnecting stuff from engine and transmission and getting it ready for removal. Tomorrow I'll play tug of war with it. That should be fun.

[Navatech]

Originally Posted by sailorchic34

let alone a $200+ compression tester

Craftsman is currently selling their compression tester for $58.49 (regularly $64.99)... Harbor Freight has their basic diesel compression tester currently for $29.99...

[dlockhart]

For certain you have a broken ring land or 2 due to someone giving it a sniff of either in the past. Little Yanmars don't mix well with either, I've had the same experience. New piston with rings was in the $140. range as I recall. I ended up going oversized with new seals, bearings and cam bearings. Good luck.

[SaltyMonkey]

This is inspirational.

[IdoraKeeper]

Must plus one on all the praise. This is what boats are all about.

[s/v 'Faith']

Hey Chick,

First, add my voice to those telling you how cool you are. I hear folks say how they " could never do that" and you are doing it.

I know you said $$$ is tight, but in the midst of everything else you are doing, please send your injectors in to a good shop to have them tested. #3 may have been damaged by either as the earlier poster said.... But lack of fuel from a slow-to-pop injector could cause problems too...

Hate to see you fix one problem without fixing the one that caused it in the first place.

Good luck!

[Cheechako]

Originally Posted by dlockhart

For certain you have a broken ring land or 2 due to someone giving it a sniff of either in the past. Little Yanmars don't mix well with either, I've had the same experience. New piston with rings was in the $140. range as I recall. I ended up going oversized with new seals, bearings and cam bearings. Good luck.

Yanmar seems to have had a piston problem on that engine..what vintage is it? Could be the fact that mechanics were trained to tell customers to run them near max rpm 3600.... I used to run mine at 3200 sometimes... sounded like an airplane! ... and both engines failed prematurely. Of course it's really only about an 18 hp (?) engine rated much higher at much higher rpm!
Are these engines sleeved? cant remember... hope so... so it can be fixed.
Bummer......

[Cheechako]

Originally Posted by Navatech

Craftsman is currently selling their compression tester for $58.49 (regularly $64.99)... Harbor Freight has their basic diesel compression tester currently for $29.99...

Diesel engines usually require a screw in compression gauge to get a good reading. (you cant physically hold it tight enough) so you also need to have an adaptor machined.....