86 120hp merc wont run wot.

First time boat owner, 1986 stingray svb 176 ss, mercrusier 2.5l 120 hp i/o, sei 106 out drive, 14.5x19 prop. Now that that is out of the way, I just became the proud owner of this fine vessel my first real boat. When i got the boat home I replaced the points, condenser, plugs, cap and rotor. I filled it with fresh fuel and started it up on muffs. The boat seamed to run well in or out of gear and at idle. To the lake we go, when I throttle up the boat it will not go past 2600 rpm. So I had the carb rebuilt, the mechanic said it was a little dirty but not bad. Tried it again same problem, what gives? Someone had mentioned that the bellows in the exhaust could be stuck? Anyone have any ideas any help would be great. Thanks.

Re: 86 120hp merc wont run wot.

I am assuming you have checked the basics like timing. Have you checked the compression? An SEI drive would be a replacement. Is it the correct ratio? I don't know how the bellows would be stuck, maybe the shutters but I think that would cause more of an issue. I have a similar boat with same engine and can hit 4400 rpm with a 19p easy.

Re: 86 120hp merc wont run wot.

plumber3 said:

replaced the points, condenser, plugs, cap and rotor. I filled it with fresh fuel and started it up

Click to expand...

no mention of the fuel filter.

after fuel filter, I would have a look for rust or gummy oil gunk on the advance weights and springs in the distributor (underneath the plate where the points go)

Re: 86 120hp merc wont run wot.

Howard Sterndrive said:

no mention of the fuel filter.

after fuel filter, I would have a look for rust or gummy oil gunk on the advance weights and springs in the distributor (underneath the plate where the points go)

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The fuel filter was changed, i will pull the dist apart today. I still need to check the compression, what range should they be in? Thanks for the help

Re: 86 120hp merc wont run wot.

Welcome.... Have a look in the Sticky at the top of this forum. It's full of good info:

List of possible causes of low WOT (Wide Open Throttle) rpm.
http://forums.iboats.com/showthread.php?t=295070

Plumber from the northeast
where in the northeast?

Re: 86 120hp merc wont run wot.

Eric 3.7LX Alpha 1 said:

Welcome.... Have a look in the Sticky at the top of this forum. It's full of good info:

List of possible causes of low WOT (Wide Open Throttle) rpm.
http://forums.iboats.com/showthread.php?t=295070

Plumber from the northeast
where in the northeast?

Click to expand...

Thanks, working my way throught the list now. My northeast would be in the central maine area.

Re: 86 120hp merc wont run wot.

Checked under the plate in the dist, all clean and working good. compression test complete found all four cyl around 115-120 psi. Is there an easy way to check the dwell, does it require ant special tools?

Re: 86 120hp merc wont run wot.

plumber3 said:

Checked under the plate in the dist, all clean and working good. compression test complete found all four cyl around 115-120 psi. Is there an easy way to check the dwell, does it require ant special tools?

Click to expand...

Ayuh,.... 115/ 120 ain't the best numbers,.... She's Tired....

Dwell is set with a dwell meter,...

Have ya tried a smaller prop,..??

"My northeast would be in the central maine area."
Starsnstrippers, lives just outside Searsport,....

Re: 86 120hp merc wont run wot.

I tried it with a 15.5x 15 prop first. No difference.