115hp mariner red stripe runs away

[twostroke87]

I have this 115 mariner red stripe, the only number i could find was on a plate and is 6127508, i'm thinking maybe its a 1975? Its an inline 6, and it starts right up with a turn of the key the only problem is it takes off like dog chasing a rabbit, immediatley just runs to as high rpms as possible a scream so loud that its almost deafening. The first time it happened there was a problem in the key switch and it wouldn't turn off, so i had to pull spark plug wires, would you believe that after I pulled every wire off it was still running on the bottom cylinder i couldn't get the wire off of! I know what i have to do to fix the turning off issue, but when i ran it again i checked to make sure that the throttle plates where almost all the way shut, yet it still took off screaming. That leads me to beleive that its sucking air somewhere, yet all the carbs are tight and the gaskets look like they are in one peice.

Any ideas as to where this thing might be sucking air, or if possibly a timing issue could cause this? Someone told me the floats could be stuck down but usually that just makes the engine not idle due to flooding. Once you shut the plates it should die, so even if they are stuck, where is the air coming from?

Thanks for any ideas. Jim

 

[Inline6]

Re: 115hp mariner red stripe runs away

Its takes an air and fuel mixture (plus compression and spark timing) to run, and the fact it kept running even on one cylinder tells me that all things considered you are not to far away from having this "wild beast" run properly.

Find the "Link & Synch" discussion and make those adjustments (I think it is a FAQ topic). (That adjustment sequence is an excellent description and may correct your problem on its own).

Since it was your bottom plug wire you couldn't disconnect, I would get a mirror and look at the throttle plate opening for the bottom carb. If memory serves me (any it does not always!) the carb throttle blades are closed -or very close to it - at idle.

One thing that you want to be careful about - if you have ever disconnected your fuel hose in order to run the carbs dry - you will notice that right before the engine dies it picks up speed considerably. That is caused by a lean mixture condition and that is really tough on the inline six engines. I would check and make sure your idle mixture screws are set at least 1-1/2 turns open from lightly seated (preferably 1-3/4 but engines do respond differently to settings).

Good Luck,
Inline6

 

[twostroke87]

Re: 115hp mariner red stripe runs away

ok i found the link, very informative. Sounds like what i probably need to do, I'm trying to get my hands on a 2 stroke timing light. If I have any more problems i'll post again

Thanks again jim

 

[Chris1956]

Re: 115hp mariner red stripe runs away

Jim, There is no such thing as a 2 stroke timing light. Any timing light will work.

 

[twostroke87]

Re: 115hp mariner red stripe runs away

sometimes they work, but the one i have doesn't work on it. Its cheap, works on the 4 stroke I/o engines fine but when i put it on a 2 stroke the flash is erratic and then just stops for 10 secs then flashes erratically again, doesn't matter anyway after 2 run aways it ate the piston in cylinder 3, theres a hole the size of my thumb in it. off to the scrap yard it goes.