9.8 Mercury 110 Hard to start

Hi guys I have a 1975 merc 9.8 that has been sitting for a long time, I replaced the water pump and its working great. But this motor is ridiculously hard to get started, the only way I can get it to start is spray some pre mix in the plug holes and it fires right up and runs good, very responsive to the throttle. What could be causing this problem?

Re: 9.8 Mercury 110 Hard to start

My mariner 15hp had the same problem after a long time with out usage. Mine has electric start so it was easier to muck around with. I started with having to put fuel in the carb then after about 5 starts I would only have to choke the carb with my hand than it would start. The reason why you maybe having problems is theres a restricten somewhere. Check your fuel lines for dryed up flaky deposits. Make shore the connection to the motor is clean. That bulb needs to be in shape too. In my case I had dryed up fuel blocking the connection to the motor..

Re: 9.8 Mercury 110 Hard to start

Thanks for the reply I was thinking it could have something to do with my fuel line because the bulb won't get firm but it's a newer fuel line that's just been sittin on my shelf and I have it directly connected to the fuel pump at the moment because I lost the fuel line quick connect. Could it be a carb issue even though once its running I can rev it up with no problems ?

Re: 9.8 Mercury 110 Hard to start

If the idle jet is still not clean good, it could be the trouble Have you checked the link an sync of the carb linkage since you have had the carb off for cleanning? You ca get a can of Power Tune and spray it into the fuel inlet to the carb and let it stand per the directions and see if that helps. Power Tune can be bought at a Merc dealer and it has worked wonders for me in the past. Spray enought into the carb feul inlet till it comes out in the throut of the carb. It will smoke like crazy till the stuff is run thru the motor and will stop and be fine. Check the spark and see if it will jump a good 3/8 inch and is clear and snappy. JMO
Oldman570

Re: 9.8 Mercury 110 Hard to start

It's becomes really obvious when you hit the water and it idles fine and then you put it gear it starts moving then it dies when it starts needing More fuel. If you can't get that bulb really firm then you will have trouble trying to start it. My motor won't start unless I can get that bulb pumped up hard. It's a pain LOL

Re: 9.8 Mercury 110 Hard to start

I'll give that idle jet a good spray with cleaner and try anothe fuel line I have , I did not do anything to that jet while I had the carb off. This may seem like a dumb question , how do I link and sink that carb? Since there's not really linkage on it , it just opens/closes via a plastic nipple on the top being moved with the throttle moving another piece of curved plastic (sorry for the bad description)

Re: 9.8 Mercury 110 Hard to start

Another thing that could be causing you troubles is the fuel pump on the motor not pumping enought fuel when it is needed. The diaframs will get hard or crack from setting for long periods of time. You will need to test the fuel flow from the pump by disconecting the hose from the carb and placing it in a can or jar and pull the motor over to see if there is a good stream of fuel from the pump. Ethenol in the gas will deterat the older rubber used on several parts of the fuel system. if that fuel has been used, and the motor was not prepared for long time storage. If you do not have a manual for the motor, now would be a good time to invest in one, as it will go into some detail as to the link an sync of the timming and carb linkage setting and is a good investment if you plan on keeping the motor. Bring a motor back to life can sometimes be quite trying and the knowlage learned from doing one will not be forgotten very quickly. The roller on the carb has to be set with the plate just so the timming and carb are in sync for the motor to start and run up in RPM's correctly. When working on the motor ALWAYS have the LU submerged in a barrel of water atleast 5" over the cavation plate if the motor is going to be started and run, as damage to the water pump impeller spining while dry will ruin it very quickly. If the motor runs at a idle and has the older point ing. DO NOT do anything to them, as it takes alot of work to get them set correctly again.JMO
Oldman570

Re: 9.8 Mercury 110 Hard to start

Thank you for the information , I will inspect the fuel pump over the weekend. As for pulling the line going from the fuel pump to the carb how do I go about doing that test since the fuel pump is part of the carb and it's fixed mounted to it?
Also I'm trying avoid spending extra money on this motor to buy a Manual I got the motor for nothing from a buddy and it's just going on a small Jon that Is used in the canal by my house.
I'm a johnnyrude fan and not familer with these old mercs , I do have a 40 merc on my whaler buts it's a lot newer. Are these motors worth putting effort into or is it always going to be a pain to keep it in running condition ?

Re: 9.8 Mercury 110 Hard to start

Clean and rebuild the carb and fuel pump 50 bucks for the kit. You got the the motor for nothing.???

Re: 9.8 Mercury 110 Hard to start

I got the motor along with a parts motor for 50 bucks from a friend so basically nothing. I'm going to pull the fuel pump off the parts motor and see if it makes a difference , the carb had no gunk in it since it was drained before the motor was put up but I'll double check the idle jet. And this motor has been rebuilt ( so the story goes). It's super clean under the cowl new paint etc

Re: 9.8 Mercury 110 Hard to start

Just buy the rebuild kit. why are you wasting your time. Done.