1989 Force 125hp Bad Bog on acceleration?

[MikDee]

Newbie to this forum, but I have been a backyard mechanic forever (or so it seems,,,lol) My son a newbie to boating, recently picked up a 1989 19' Bayliner Bowrider package with a 125hp force motor, with the help of my guidance, boating, & mechanical knowledge. I never had a Force motor, or Bayliner boat but I was impressed by it. Anyway, the motor starts, runs, and idles fine, but when I "Hit it" from idle, it bogs terribly, but eventually gets up to top speed, and runs smoothly, although it appears not very fast? I have no tach, but the speedo only says 25mph fully wound out? I figured it should do maybe 35mph. I noticed it didn't seem to matter if we had 5 people, or 2 people in the boat, still the same results. I also noticed it has a 15" pitch prop on it, and figured a 17" pitch prop would have been the correct one, but I dare not mess with that right now. I did a compression check before he bought it, and it was low, (120lbs all 4) but I still think it should have more power, I put some new Autolite (equivalent) surface gap plugs in it recently, it had NGK's in it, (they didn't look bad), but I figured let me take that out of the equation, no real difference,,, all the fuel filters are clean, and the carbs, & advance mechanism, are all opening fully! I'm thinking maybe clogged carb jets, possibly an intermediate jet? But, I don't know these Force engines, if there might be any other common issues?

 

[roscoe]

Re: 1989 Force 125hp Bad Bog on acceleration?

If it is a clogged carb issue, then you are running some of the cylinders lean on both gas and lubrication, not good.

A tach would help to optimize performance and set up.
Compression is ok for that motor, start worrying if it gets down around 105 or below.

Have you checked for spark on all 4 plugs?
Could run surprisingly well on just 3 plugs, just lacking in the performance you described.

 

[MikDee]

Re: 1989 Force 125hp Bad Bog on acceleration?

If it is a clogged carb issue, then you are running some of the cylinders lean on both gas and lubrication, not good.

A tach would help to optimize performance and set up.
Compression is ok for that motor, start worrying if it gets down around 105 or below.

Have you checked for spark on all 4 plugs?
Could run surprisingly well on just 3 plugs, just lacking in the performance you described.

That's what I was most concerned about.

I don't think he'll invest in a tach

I kinda thought the comp. was not bad, very even, and also a dead cold reading, before I did anthing else, when checking out the boat to buy it.

Idle, and WOT are smooth as silk, just don't seem as fast as it should be, sounds like the motor is not revving out completely, I doubt it could be losing spark in between.

The boat history, it was used in fresh water till 4yrs ago, when the previous owner had the bottom painted, and put it in salt water in NJ for the last 4 yrs, he was not very mechanical, but kept the boat serviced at the beginning , & end of the season, I have every bill, and have gone over them, nothing unusual there. The guy said he used it very little the last few years, maybe 3 times a year. He was an older guy, and seemed pretty straight up. The boat is now in a fresh water lake again.

Can someone tell me what speed I should expect from this combo?

 

[millercm1]

Re: 1989 Force 125hp Bad Bog on acceleration?

Hi,
I also have a 1989 Bayliner Capri 19" bowrider (thaught it was 91 but actually 89), mine is a 150 though and I am just trying to get through a similar problem, my motor is "bogging".

I thought it was a fuel problem for sure and completely overlooked the thought of one of the cylinders not firing. The motor ran extreemly smooth when idleing or with open throttle, only lacked power, couldn't get the rpm's up. My max speed was 35 mph when I should be seeing 45 - 48 mph, as I was before this problem.

After checking the fuel system I changed the plugs hoping for the best, but no change when I put it back in the water. Finally I decided to check for spark on the plugs. 5th cylinder hadn't fired at all, plug was still brand new!

I have been working through this electrical problem. (See thread on this site titled 1991 Force 150 no spark on 5th cylinder.)

Hope this helps.... I would suspect if I can get 35 mph on 4 cylinders so should you.

CM

 

[MikDee]

Re: 1989 Force 125hp Bad Bog on acceleration?

Hey Miller thanks for the reply, it's good to have an idea of what should be approx. top speed. Sorry to hear you're having similar issues. It looks like all my plugs are firing, but I'll have to recheck that first chance I get. By the way, my boat capacity tag says maximum 125hp, if yours is the same as mine, does it say the same thing? If so hows it holding up with the 150hp on it?

 

[baxtr]

Re: 1989 Force 125hp Bad Bog on acceleration?

Mine 1989 19' bayliner with 125 force did the same thing last year, but had a bad cylinder so i rebuilt it. Is your fuel line bulb staying firm? tank venting problem?? these are just guesses,

also here is a link for a cheap tach, you should need the 20 pole.

https://www.shop.sporqster.com/displayProductDocument.hg?productId=607

 

[MikDee]

Re: 1989 Force 125hp Bad Bog on acceleration?

Thanks for the info, & link baxtr, Nice tach! The boat has a built in 32gal tank I think those items you mentioned are good, but I'll recheck them. The problem is, the boat is my son's (newbie) in NC, and I'm (an old salt,,,lol) in Pa.

 

[MikDee]

Re: 1989 Force 125hp Bad Bog on acceleration?

Ok, here's the latest report from my son in North Carolina, he put 12gals of fresh gas, and oil in the boat, and took it out yesterday. He said it started right up, & ran fine all day, first shot out of the channel he hit the throttle, & it took right off, no bog! He was out on the lake for 3hrs, at times stopping to drift, & swim off the boat, and each time he shut it off, it started right up. He also said with an almost full tank, and 2, then 4, people on the boat, it was up to approx 32mph. I am inclined to think the boat just needs to be run in to get past the old gas, & winterizing (stabil) in the gas tank, and the fact that the previous owner used it very little the last few years, maybe 3 times a year, and he was older, & not the type of guy to go speeding around.

 

[baxtr]

Re: 1989 Force 125hp Bad Bog on acceleration?

mine is a built in 32 also, same boat and motor. should still have a vent and bulb

 

[Matty B]

Re: 1989 Force 125hp Bad Bog on acceleration?

I also have an 89 Bayliner with the Force 125, however mine is an L-drive... are they pretty much the same power head? It looks like an outboard...

 

[baxtr]

Re: 1989 Force 125hp Bad Bog on acceleration?

I also have an 89 Bayliner with the Force 125, however mine is an L-drive... are they pretty much the same power head? It looks like an outboard...

basically an outboard powerhead on an outdrive, but not exactly the same, I think the pistons are bigger dia. also

Also, I run stabil (fuel conditioner) in my boat all season, I am not able to get mine out every week to keep the gas fresh, and I have been told anywhere from 10 to 30 days, gas starts to varnish.