88' Mariner 115 Not at full speed.

[fabrc8r]

Went out to do a bass tourny tonight and the 115 wasn't running right, idle up fine, started ok, put it in gear and barely went 5 mph at full throttle. It sounded different though, definitely could hear something wrong. I don't think I am running on all cylinders. Recently I had an ignition box changed about 4 months ago, boat has been running great since then, took the family skiing on sunday. Its a tracker 1800 f/s. Could this be fowled spark plugs? I am fairly mechanical, anything I can rule out would be helpful? Have to check the plugs tomorrow as it is night now. Also if anyone knows where I can adjust my idle that'd be helpful, it doesn't idle without throttle.

 

[gregpro50]

Re: 88' Mariner 115 Not at full speed.

Check to see if it is getting spark on all cyls. Sounds like an ignition problem to me.

Once you get it running good, set the idle no more than 1000 RPM or shifting will be really hard on the lower unit.

 

[CraigC]

Re: 88' Mariner 115 Not at full speed.

It sounds like it's probably spark related to me as well, you'll want to make sure you have spark on all cyls for sure. Take a look at the plugs, could be as simple as that, or it could be a more serious ignition issue.
Perform a quick visual inspection of all the wiring and make sure nothing is frayed or burned through - sometimes the coating on the wires gets brittle (due to time and from heat) then it breaks away and things short out.
I would get a manual, if you don't have one already, and once you're sure you have spark I'd go through the link n' sync procedure - that'll help with the idle problem if it still doesn't idle right after you ensure you've got spark.

 

[fabrc8r]

Re: 88' Mariner 115 Not at full speed.

thanks, checking sparkplugs and wiring tonight, how do I set the idle on the tower of power inline 6? Also i haven't performed any preventive maintenance or oil level checks, does this have a checklist that i should be doing after a certain # of trips on the lake?