Yanmar 1gm10 valve seats

[candide67]

Hi all ,

I'm in the process of refurbishing my 1gm10 engine , due to rings blown , so thought I give it a total rebuild , common problem I know my exhaust valve seat is pitted quite badly , Ive tried lapping the pits out but to no joy , my question is can these valve seats be replaced , any ideas . has don't wont to buy a new head due to £££££££££££.. thanks in advance Neil

 

[rotrax]

Hi all ,

I'm in the process of refurbishing my 1gm10 engine , due to rings blown , so thought I give it a total rebuild , common problem I know my exhaust valve seat is pitted quite badly , Ive tried lapping the pits out but to no joy , my question is can these valve seats be replaced , any ideas . has don't wont to buy a new head due to £££££££££££.. thanks in advance Neil

Take it to an engine reconditiong specialist. You might find it cheaper to use a non marine outfit-after all, a valve seat is a valve seat, nothing special about a marine one.

They can cut or grind the valve seat so the valve will seat. If it is too badly pitted the seat can be replaced, still cheaper than a new head.

IIRC the 1GM10 has an iron head-re-cutting or grinding a new seat will probably be enough. Probably need a new valve too.

 

[RichardS]

Take it to an engine reconditiong specialist. You might find it cheaper to use a non marine outfit-after all, a valve seat is a valve seat, nothing special about a marine one.

They can cut or grind the valve seat so the valve will seat. If it is too badly pitted the seat can be replaced, still cheaper than a new head.

IIRC the 1GM10 has an iron head-re-cutting or grinding a new seat will probably be enough. Probably need a new valve too.

Certainly worth taking it in .... but I think that some parts of the GM head are cast rather thin so I'm not sure how much metal there is to play with.

Richard

 

[JumbleDuck]

I'm in the process of refurbishing my 1gm10 engine , due to rings blown , so thought I give it a total rebuild , common problem I know my exhaust valve seat is pitted quite badly , Ive tried lapping the pits out but to no joy , my question is can these valve seats be replaced , any ideas . has don't wont to buy a new head due to £££££££££££.. thanks in advance Neil

My local engine place (McKeands in Dumfries) were happy to have a go, but said that the casting is so thin that seats sometimes cannot be fitted. Never found out, because the head fell to bits while they were cleaning it.

 

[DownWest]

We found that salt water had corroded both the exhaust valve and the seat. Local good machinist (does lots of classic car stuff) fitted an insert and we found a valve on line for £20. Done a few hours this season.

Ours was quite bad and needed both renewed, but yours might just be sorted with a reface and valve grind on a rig. Depends on the corrosion, so talk to a decent machinist.

 

[nemodreams]

As for re-seating - yanmar workshop manuals are, as usual, full of anomalies?
Section 2-2.6 says - measure the seat width calipers and if wider repair or replace the seat ....?
Yet on the same page 2-2.7 - they say " when the valve has been lapped many times - and the valve head is below limit - replace valve and head ?

If you are going to re-seat them - bear in mind the specs on valve head recess.
I have the workshop manual if you need info - its very thorough ( when it gets it right ! )