Export thread

This engine mounted on a SxS will only idle if on full choke. Runs fine at full throttle, but immediately dies if even slightly taken off choke. Have adusted valve clearances, replaced spark plug, checked compression which is 95 and is within range for this engine. Have replaced carb, all intake gaskets, and the isolator with new gaskets. Tried an alternate fuel source with no change.

Sounds to me like the idle circuit is completely clogged. Main nozzle is acting like the idle port when choke is closed.

I know that is what is sounds like, but what is the chances the a new out of the box carb would have the same issue.

Don’t know if you have this manual, but pages 3-50 through 3-69 have your carb and might be of some help. https://rentamaxcr.com/manuales/manual reparacion carburadores HONDA GX.pdf

Rivets, I think I have located the problem. And the engine is toast. The issue is a compression problem, even though compression is in the normal range. The issue is running a compression check with the throttle open as recommended is giving the equivalent of a wet compression reading. After running the engine for a few minutes and then doing a hot test is giving closer to 70-75 psi.

Basically not enough compression at idle speed to create sufficient vacuum through the intake without the extra choke.

I’ve got to remember that one, thanks for the update.

If I had the time I’d run a leakdown test to verify what the cause is.

Rivets said:

If I had the time I’d run a leakdown test to verify what the cause is.

Click to expand...

I am certain the cause is long term dirt ingestion due to an ill fitting air filter. Basically the rings are shot. Which would explain the difference in cold vs hot compression.