8HP Surging and Missing

[Rick K]

Hi all,

My 8hp, model 8CM (presumably an '88 model) is surging and missing at low speeds. Although I put new plugs in her in March, I figured I'd change 'em to see if it would help.

It helped a bit, then went back to surging. Bought a new fuel tank (but not the hose), as it was a bit ratty, but no-go. I picked up fuel pump diaphragms, but didn't install yet, carb rebuild kit is on order.

The motor starts on a half-pull, will run all day and night non stop, except for that surging and missing.

If this was my old battle wagon Johnson, I'd know where to start.

Should I go with the diaphragms to see if that helps, or just tear into it when the rebuild kit arrives?

Advise and/or opinions are appreciated.

Thanks
Rick

 

[Rick K]

Re: 8HP Surging and Missing

Oooops, almost forgot: The motor doesn't miss or surge at 1/2 throttle and up. At WOT, she screems. Also, could the quality of my gas (Sunoco 89 Octane) be causing this, with their 10% ethanol?

Thanks again
Rick

 

[deejaycee_2000]

Re: 8HP Surging and Missing

Your fuel should be fine .... replace the diaphram, and do the carb rebuild, then you know it's done ...soak the carbs in carb cleaner for 24hrs and blow out with comressed air ... see what happens ..

 

[Rick K]

Re: 8HP Surging and Missing

Thanks deejaycee - I haven't had time to rip into it, and, the carb kit is still on back order. Will have to wait till all the parts are in.
Rick