mercury 110 9.8hp thunderbolt fuel problems ??

[thunderbolt 110]

Hi all
i,ve just got a mercury 110 9.8hp thunderbolt its got a blueband around the lid. i have searched for make/year on web but with no joy. s/number 9034964 any idears???? Now for the running i've changed a faulty ig/coil and getting a great spark on both plugs but engine will only start in gear and on full throttle with the carb pumped full of petrol/gas and cuts out after a few seconds. i have striped and cleaned the carb and eveything seems ok but it must be a fuel problem????? can anybody help.

 

[Laddies]

Re: mercury 110 9.8hp thunderbolt fuel problems ??

It sounds like you need a fuel pump kit, Use a OEM kit as it contains the check valves and aftermarket don't.

 

[thunderbolt 110]

Re: mercury 110 9.8hp thunderbolt fuel problems ??

Thanks for reply Laddies
the only known fuel pump system to me is the diaphragm on the carb. i have took this apart and all seams ok ( no rips and filters clean ) is there any other pump system on the engine ??
I am waiting for delivery of mercury manual but all info helps
Cheers....

any idear on manufacturing year ????

 

[Laddies]

Re: mercury 110 9.8hp thunderbolt fuel problems ??

Well it's newer than I thought so disregard my first answer. I seem to have missed that you gave a serial number. It's a 1973 Belguim built engine. Things that you will need to check on the carb are float lever and making sure that the idle pickup tube is clean, I would suspect the idle tube is plugged.

 

[thunderbolt 110]

Re: mercury 110 9.8hp thunderbolt fuel problems ??

Hi all
Just about ran out of patience with this motor, Sparks well, plenty fuel in carb and still wont start ive even flooded the carb, pulled it over and over took spark plugs out and they are bone dry ?? doent seam to be pulling fuel through carb, could it have damaged reed valves due to it being stood dry for some time ?????????

 

[Cornell]

Re: mercury 110 9.8hp thunderbolt fuel problems ??

I have similar problems with my '73 Merc 7.5 HP which should be the same basic motor except carb. But when I prime it by squirting fuel into spark plugs or past carb venturi it will start and run good. Have you tried that? That might help someone figure out your problem. But my motor has good compression which is necessary to suck gas into cylinder to ignite when pull starting. Make sure your choke is closing correctly. I feel that I will have to put new carb gaskets to see if it will help me. I think the fuel pump is connected to the carb and hope those gaskets are included in the kit I bought.
Cornell

 

[thunderbolt 110]

Re: mercury 110 9.8hp thunderbolt fuel problems ??

Cheers for reply Cornell
i,ll give it a go with the fuel in the chambers and pass the venturi,
but i have replaced all fuel pump gaskets, new spark plugs, good spark on both plugs, new fuel with a 50:1 mix, checked primer bulb and line all OK, There seems to be good compresion on both cylinders.
Engine will start after a lot of messing around and only in gear on full revs, it will run for 10 secs then completly cut off and die....

 

[2Cojones]

Re: mercury 110 9.8hp thunderbolt fuel problems ??

I'm a newbie w/ this motor, but I do know motors. Laddie is right: if what u say is correct, then your fuel supply is plugged somewhere.

-2C

 

[Dennis123]

Re: mercury 110 9.8hp thunderbolt fuel problems ??

Hey did you fix that problem?

 

[bluebull]

Re: mercury 110 9.8hp thunderbolt fuel problems ??

i have simular problem with my 9.8 if i bypass fuel pump and hook fuel line directly to the carb engine rums fine as long as i keep the bulb pumped