Hard Starting 1987 115 I6

[PACERll]

I own a 1987 Merc 115hp I6. The problem is it is a bugger to start when it is cold or been setting for a say hoir or so. The carbs have been rebuilt to specs have done comp check they are in specs and have also done leakdown tests and as well they are in specs. RunningL78vplugs and they are all the same color. once engine fires it runs excellant. I beleive the mixture jets are set at 2 turns out from being slightly seated. The best way to get this motor to fire up and run is to trim it all the way under and choke and crank like crazy. HELPPPPP I know I have missed something or havent done something right. If anyone can help me that wuld be greatly appreciated.<br /> 1FASTLASER

 

[gewf631]

Re: Hard Starting 1987 115 I6

1FASTLASER<br /><br />My '86 is exactly the same - pump the bulb like crazy, choke, choke, choke some more, and fast idle until she's going.<br /><br />If you search through this forum, you'll see many others in the same boat (pun intended).

 

[jimmbo]

Re: Hard Starting 1987 115 I6

Those motors don't have a choke. They use a primer system that, using a solinoid valve drains gas from the top carb fuel bowl into either the reed blocks or into the transfer ports of a couple of the other cylinders. It is possible the primer system isn't working anymore.

 

[emckelvy]

Re: Hard Starting 1987 115 I6

Check the primer system as stated previously. With the primer dumping raw fuel right into the motor, it should lite off instantly. Try manually priming the motor by opening up the brass valve on the priming unit. If the motor lites off OK, there's a problem with the solenoid itself or power to the unit.<br /><br />You could also try fogging a fuel-oil mix into the carbs and see if she'll fire. If so, suspect the primer. Otherwise you may have other issues such as loss of crankcase vacuum (bad seals, etc). However, since you say it runs well otherwise, likely it's something to do with the primer. Goes without saying that the primer only operates while the choke button is depressed.<br /><br />As an aside, you say you're using L78V spark plugs. These are too hot of a plug for your motor.<br /><br />L76V's are a colder heat range and spec'd for your motor.<br /><br />Another critical area on the inline's is to ensure that your timing setting is no more than 21 deg BTDC at cranking speed.<br /><br />HTH and Good Luck.........ed