Possible loss of compression?

[Spivy30]

I have a 1986 Bayliner 2150 Capri with a 5.7 and a Volvo Penta drive. When I first got the boat it was running great then after a few times out it started to miss and bog at higher rpms. I figured it needed a tune up so I put a new rotor, condensor, and new plugs. Its started a lot better but still bogged so I thought it might be the accelerator pump so i checked that and it was fine. Next I thought it might be old gas so I ran it down to about a half tank and filled it up with fresh gas. I took it out tonight and it wouldnt even get on plane it feels like it has no power. It feels like it has power until the secondary opens up on the carb but at the sametime I feel like it might just have no compression. I checked to make sure all the plug wires and everything were tight. At this point im stumped and im supposed to be going on vacation saturday morning and taking the boat.

please help

 

[Bt Doctur]

Re: Possible loss of compression?

spark plug wires not in the correct order, 1,8,4,3,6,5,7,2
F
1 2
3 4
5 6
7 8
dead cylinder, do a compression test, and leakdown test.

 

[jtybt]

Re: Possible loss of compression?

Always do a comp test with an unknown engine problem. A vacuum reading is even quicker.

Don't leave out a fuel flow problem.

 

[Spivy30]

Re: Possible loss of compression?

I guess i'll have to do a compression test and check the plug wires. I pulled the fuel line off and checked the filter and they seemed fine I think I might just rebuild the carb while i'm at it.

 

[AZSenza]

Re: Possible loss of compression?

Its been my experience a bad cylinder shows up more at idle that WOT and fuel/ignition issues are more noticeable up top RPM wise, thats my 18 cents..(Inflation)

 

[Maclin]

Re: Possible loss of compression?

The carb may have clogged jets and passages, and is leaning out the fuel mixture bad when the secondaries start opening. Carbs do need a little attention every 10 years or so, yours may be overdue.

 

[Spivy30]

Re: Possible loss of compression?

I cleaned the carb and retimed the the motor and it runs alot better but it still bogs at the top end

 

[Haut Medoc]

Re: Possible loss of compression?

Checked the filter?....
Did you replace the water separating fuel filter?....
There is really no way to 'check' them....

 

[jerryjerry05]

Re: Possible loss of compression?

Sounds like a fuel supply problem.Replace ALL fuel lines with NEW!!! Ethanol might be destroying the old.CHANGE not clean all fuel filters.If you don't have a fuel/water seperating filter put one in.That year Volvo came standard with a fuel/water filter but they were a pain and usually were removed or overlooked. The carb has a filter,change that too.
Check for water in the tank.Check the vent line for blockage(wasps).J