18 replies to this topic

[dklawson]

I know very little about H carbs.  However, they do have a side mounted float bowl like the HS series.  As a quick clean, try the following.

 

Remove the float bowl lid and use spray carb cleaner to wash out the gunk in the bottom of the bowl.  Use paper towels to blot up the mess.  Do not put the bowl lid back on yet.

 

Carefully remove the suction chamber from the carb.  Be careful not to damage the needle.  Use spray carb cleaner on a coarse cloth to remove any gum and varnish on the needle.

 

With the suction chamber removed, use the spray straw of the carb cleaner to direct several sprays of carb cleaner down the jet.  The spray cleaner should come out in the float bowl.  Use that soft plastic spray straw to scrub the inside walls jet.  Use nothing metal, only the spray straw.  Keep doing this until the fluid coming out in the bowl is clean(ish).

 

Put the carb back together, put oil in its dashpot and try running again.

[carbon]

Dennis,

 

Like yourseof I have reused old petrol which had been sat for a couple of years in fuel tank. I drained this out into jerrycan and not wanting to waste it I used some in the lawnmower.

 

The lawnmower ran fine first time I used the old petrol, so I was wondering what all the fuss was about using old petrol.

 

Then I went to start the lawnmower up the following week, and found the engine had no compression at all and making strange noise. Turned out the exhaust valve was jammed solid in the guide, had to take the head off and apart to free it up. Got it running again but that was full afternoon wasted. I have been using fresh petrol in the lawnmower ever since and not had any further bother with sticking exhaust valve.

 

Strongly suspect the cause was the old petrol, likely has formed dissolved gums which then caused the exhaust valve to stick in the lawnmower. Just pleased I didn't use this old petrol in a mini engine, that could have ended up being messy/expensive.

 

So would suggest being careful when reusing old petrol in engines, particularly if it has turned orange...

Edited by carbon, 11 October 2015 - 12:54 PM.

[dklawson]

Of course... it could be used (carefully) as a parts cleaning solvent.

[dennismini93]

The mini seams fine after the old fuel luckily but the engine is coming out soon anyway so it wasn't really a worry.

The riley is running well now. I corrected the timing and got the fueling set up on a Co machine and it's much improved.

Thank you for all your help