Merc 1978 110 9.8 hp wont stay running

Hey all, I have a 78 9.8 that stopped running last summer. I had it in the garage over the winter and this week I took the carb apart and cleaned it out and put in a gasket kit. It was quite dirty with a couple of blocked lines.

The plugs are good and I get a descent spark (holding the plug against block and turning it over). Priming it while it is running has little effect.

It starts easy enough but only runs for a few seconds. Every once and a while it will seem it backfire while trying to start it.

The slow speed needle is set 1 1/2 turns our from seated.

BTW: The impeller was changed out last summer and water flow is good.

Any ideas as to what I should look at next? Getting frustrated with it now....

Thanks

Re: Merc 110 9.8 wont stay running

Once you get it to start try pumping the fuel bulb on the gas line.

If that keeps it going, rebuild the fuel pump.

These little motors will cough or sneeze (backfire) if they get extra air in the air/fuel mix, which can be caused by a toasted fuel pump diaphram.

Re: Merc 110 9.8 wont stay running

I found a local merc dealer with the fuel pump kit in stock, I'll be picking it up today. The motor is 32 years old and all original (except the impeller) so it cant hurt to replace it anyways.

pumping the fuel bulb has a little effect. It runs for a little longer when doing this but does not stay running for long.

Re: Merc 110 9.8 wont stay running

I suspect the carb needs cleaning, not just a "gasket change". There are tiny passages inside it that need cleaning out.

Jeff

Re: Merc 110 9.8 wont stay running

So I picked up the fuel pump kit on the way home and put it in based on the schematic I found online. I also replaced the fuel line.

After a few sputters it did start and then reved out. I couldn't turn it off. the kill switch didn't work right away and the throttle, although seems to be working wouldn't respond.

Re: Merc 110 9.8 wont stay running

I'll bet the wiring of your kill switch is rotted all to heck. Don't know who sold Merc wiring back then, but it was awful!

Jeff

Re: Merc 110 9.8 wont stay running

Got it. Yes I am an idiot...lol

I cant believe that I put the new gasket that goes between the carb and the block on upside down covering one holes. I flipped it around and gave it a pull and it started right up on the first pull with no choke and runs better than I have heard it in years!

Idles well, can slow it right down and it doesn't stall, WOT is strong, shifts well. Wow, good for another 32 years now!

Thanks for the direction guys. Now on to the 1978 7.5 and the 1973 4hp.