Stump grinder engine.

[woody paul]

Having problems with Honda gx390 on Camon grinder, it's looking like a may need new engine. So do I go for honda or stick a Lincoln on it at half the price. 

[openspaceman]

1 hour ago, woody paul said:

Having problems with Honda gx390 on Camon grinder, it's looking like a may need new engine. So do I go for honda or stick a Lincoln on it at half the price. 

Loncin

[spudulike]

Fix the Honda if it is fixable at a reasonable cost otherwise Locin make decent replacement engines - many equipment companies use them. 

 

[Ant-h83]

i put a lifan engine on our predator 360 2 years ago, starts first time every time, and it hasn't missed a beat. im actually really impressed with it

[woody paul]

11 hours ago, spudulike said:

Fix the Honda if it is fixable at a reasonable cost otherwise Locin make decent replacement engines - many equipment companies use them. 

 

It lacks compression, and is running rich as plug gets  carbed up, and just will not run flat out. When it's running you can get it to run better by shutting fuel supply down. 

Have cleaned carb and checked needle valve. 

Will try and leak down test it and see were air comes from. 

[woody paul]

22 hours ago, Ant-h83 said:

i put a lifan engine on our predator 360 2 years ago, starts first time every time, and it hasn't missed a beat. im actually really impressed with it

Which company did you get it off, 

[spudulike]

11 hours ago, woody paul said:

It lacks compression, and is running rich as plug gets  carbed up, and just will not run flat out. When it's running you can get it to run better by shutting fuel supply down. 

Have cleaned carb and checked needle valve. 

Will try and leak down test it and see were air comes from. 

It may be that the decompressor is holding the valve open or has burnt it out. 

I haven't had one of these units apart before but typical loss of compression on a 4T engine would be piston/ bore/ring wear, valve clearance or worn seat issues or blown head gasket. 

These engines are probably like the Stihl 4 stroke engines and lift one of the valves for easy starting. When the tappet clearance is too great, starting I'd much harder on the handle. Your tappets may have too little clearance.

On the carb, make sure you get the emulsion tube that resides behind the main jet, out and clean both the jet and tube. It has small holes in it that, if blocked, cause hunting issues.

Double check the choke mechanism is opening and closing as it should....some are automatic, some are manual and then make sure the engine governor looks OK, many take them apart and don't get them back together correctly.

Just a bit of my limited experience.

Some interesting vids on YouTube comparing these type of engines, some even analysing the metal in the used engine oil. 

[woody paul]

Got a bit of time to day to iook at it again,so I found. 

It would run at full revs assembled back together, popped rocker cover off and tappets were out of setting reset them. 

Tried it again no luck, so while it was running popped breather pipe from rocker cover to airbox off and smoke like a coal fire, and engine ran better and ran flat out with no spluttering. 

So I am thinking rings gone.