100 HP Mariner 1989 Idle RPM What should it be?

[w2much]

Having a heck of a time getting my engine down to a low idle. How low should I expect it to idle. At 1000 is runs and shifts OK but that seems a bit high. Lower than that and it backfires and stalls but will start right back up again . Any suggestions? Thanks

 

[Don S]

Re: 100 HP Mariner 1989 Idle RPM What should it be?

650 to 700 is book.
Have you done a tuneup lately? Couldn't hurt.
How about a compression check?
How about a sync & link.?

 

[Texasmark]

Re: 100 HP Mariner 1989 Idle RPM What should it be?

The rpm setting Don mentioned is in gear, in the water. On muffs it may be up at 1000. Only problem with it being too fast is that it makes shifting awkward, especially reverse, and can prematurely wear out your lower unit gears (so says my Merc maint manual).

Mark

 

[w2much]

Re: 100 HP Mariner 1989 Idle RPM What should it be?

AHHHH, I was running it on muffs. Ran great in the water last weekend and idled better. I have since put in a new rectifier and my tach is now working properly. Will post later and how she runs on the water. I appreciate all responses. Thanks.

 

[w2much]

Re: 100 HP Mariner 1989 Idle RPM What should it be?

Ran and idles great on todays voyage. I guess its the backpressure needed for it to run correctly. Idle bad when I got home and flushed it out on the muffs.

 

[Texasmark]

Re: 100 HP Mariner 1989 Idle RPM What should it be?

Now that's what I call a happy ending.

Mark

 

[w2much]

Re: 100 HP Mariner 1989 Idle RPM What should it be?

I still need a linc and sync but will do it when I have a chance. New question , new post forthcoming.Thanks Don and Mark.