Hard Start on a Early 80's outboard-Merc 115 h.p.

[GTBOATER]

I've got an early 80's , 115 h.p., inline outboard motor. It has a regular "butterfly" choke on the carb. Compression checks @ 125psi+ on all cylinders. Carbs have been rebuilt. Problem is...It won't start unless you give it a shot of fuel in the carb. It idles perfect after it starts. If you shut it off, it'll start right up. If you let it set for 5 minutes it won't start unless you give it a shot thru the carb. The starter spins it around and it sounds like it has no compression, but checks out @ 125psi...I'm hoping someone will give me a hint on some ways to troubleshoot this problem...even a referral to other websites is appreciated.......thanks ....you can also e-mail me @ ....jerman@gtemail.net

 

[ODDD1]

Re: Hard Start on a Early 80's outboard-Merc 115 h.p.

GT, it sounds like your idle mix is set too lean. turn the idle mix screws in to the stops [counting the turns as you go].<br />when these motors were new they usually had 1.5 turns out from seat.....with a little age 1.75 to2 turns needed to ensure decent idle and hot start. might as well try this first, its easy. these motors were always hard to start, thats why later motors went to primer system instead of choke plates

 

[GTBOATER]

Re: Hard Start on a Early 80's outboard-Merc 115 h.p.

Thanks ODDD1--tried that. Is it possible that there is no vacuum across the carbs, even though there is compression of 125 in the cylinders?

 

[ODDD1]

Re: Hard Start on a Early 80's outboard-Merc 115 h.p.

Yes, GT when these motors wear out, the labrynth seal in the reed blocks wears away where the crank passes thru it. end result is an air leak between the 2 cylinders that are fed by that reed block/carb. so when yer tryin to start or idle the engine[minimal air flow] the motor acts lean. the other thing that helps is toraise the float height to maximum.....when i set up these carbs they will 'flood' on the primer ball but not when running. helps on the cold start too

 

[GTBOATER]

Re: Hard Start on a Early 80's outboard-Merc 115 h.p.

Thank you very much for your information, you are the only one that has been able to give me any logical advise so far. I thought it may have something to do with the reed. How difficult is it to change this particular labrynth seal in the reed block?<br /><br />Thank you again for all your help.

 

[ODDD1]

Re: Hard Start on a Early 80's outboard-Merc 115 h.p.

I hate to say it but you gotta change the reed block to fix the prob.....they are over $200 apeice an you got 3 of em. thats just one of reasons a GOOD rebuild costs $$$ as long as the motor runs ok otherwise, i'd crutch the prob with more fuel at idle......<br />you know... there is one more place that you can check...pull off the transfer port covers...in the bottom of the port[on the top 5 cylinders] you will find a 1/8" drilled hole that has a 'restrictor' in it . these restrictors are plastic and sometimes get sucked out the hole...makin a big air leak and a lousy idling engine... p/n on the restrictor is 66517. worth checking

 

[GTBOATER]

Re: Hard Start on a Early 80's outboard-Merc 115 h.p.

Once again ODDD1, you are very much appreciated with all the advice you've volunteered. Here's the NEXT question, where are the transfer port covers located?? I'm having a fit trying to find them, is there a diagram that you can e-mail me??? This sure would be appreciated, please e-mail my nephew at this address: jerman@gtemail.net Many thanks!

 

[ODDD1]

Re: Hard Start on a Early 80's outboard-Merc 115 h.p.

gt it is time to find a tech!

 

[flatsman]

Re: Hard Start on a Early 80's outboard-Merc 115 h.p.

Well, I understand --I have one of those also, I have installed an electric fuel pump and a primer valve from an evinrude and it works ---puting fuel in block --but be careful not to over do it.