Honda GX390

[Dan Maynard]

My honda head bolts came a bit loose. Hadnt really started leaking as bad as  that, but I just tightened them up and carried on. I would tighten bolts and see how it goes.

[Ty Korrigan]

Ah nuts, I found the source of the carb problem.

Dust infiltration. The new air filter isn't seated tight enough.

[spudulike]

That doesn't look good. I guess that is soil dust which will be pretty abrasive.

You may get away with re-ringing it but I guess it needs pulling apart to see where the wear is.

[Ty Korrigan]

I took it apart but have lost the images somehow.

 No obvious scoring on the cylinder though.

Re-fitted a fresh head gasket and carb which needs a tune.

I think I got the tappets done correctly.

Still burns oil.

Considering fitting a compatible Chinese engine short term to avoid having down time

 

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   then having a go at repairing the Honda myself IF I ever find the garage space and time.

Or moving the machine on with the Chinese engine fitted and buying a new grinder.

 

[Muddy42]

24 minutes ago, Ty Korrigan said:

I took it apart but have lost the images somehow.

 No obvious scoring on the cylinder though.

Re-fitted a fresh head gasket and carb which needs a tune.

I think I got the tappets done correctly.

Still burns oil.

Considering fitting a compatible Chinese engine short term to avoid having down time

 

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   then having a go at repairing the Honda myself IF I ever find the garage space and time.

Or moving the machine on with the Chinese engine fitted and buying a new grinder.

 

 

when you say burning oil, is that oil that is leaking round the head gasket then smoking off (like the photos in your first post) or has that oil leak been fixed and oil is still getting into the combustion, as a separate problem?

 

[Ty Korrigan]

12 minutes ago, Muddy42 said:

 

when you say burning oil, is that oil that is leaking round the head gasket then smoking off (like the photos in your first post) or has that oil leak been fixed and oil is still getting into the combustion, as a separate problem?

 

 

I've only briefly run it up as it needs a carb tune but the exhaust smells of burnt oil although there is little in the way of visible smoke.

[Ty Korrigan]

I've managed to get it running until hot, helps if you remember to refill the tank Dufus...

It was spluttering oil out of the exhaust briefly until it seemed to burn off and now exhaust smell has much improved.

Is the spluttering and back firing caused by the valves needing adjusting properly?

[Muddy42]

So I take it there is no longer a leak in the head, which is good.

 

It doesn't sound too bad to be honest.  Yes incorrect valve adjustment could cause those backfires and loss of power - loose valves don't seal properly allowing unburnt fuel in when it shouldn't. Also you mentioned a dirty carb, this could mess with the fuel mix and cause backfires.