Help with 15hp Gamefisher (Force)

[freeisforme]

Re: Help with 15hp Gamefisher (Force)

I've got one of those motors, mine is a 1989, 15hp Gamefisher but has no spark. My compression is 110 on both cylinders, and was told that that was low in another post here. I've got an older Chrysler built Sea King 9.6hp that looks to be a very similar motor that has 140+ on both cylinders.
The Gamefisher 15 I have looks mint clean and rarely if ever used.
I'd like to hear from some others as what sort of compression numbers these things should have.

I've got a Johnson 5 1/2hp from 1964 that only gives me 65 psi on each cylinder that runs just fine so I know a motor will run at lower compression just so both are the same.
I went so far as to take a look inside mine with a borescope, which I have access to at work and all looks great inside, no scoring or rust.

I would think that if the compression was too low, you would first notice it when in the water vs running with the exhaust exposed in a barrel or on ears. If mine does indeed have low compression, then yours is just plain worn out?
I got mine for free, so anything I put into it is all I'd have invested, so I'll most likely spring for a new ignition system unless I can find a parts motor.
There was a few used motors on eBay but not local, and one earlier power head which I'm not sure will work on the '89 or newer motors?
I'm guessing that mine will gain some compression after it's up and running, since it's been sitting for 20 or so years. It's already showed improvement just after me cranking it over and over testing for spark. I may pour some Seafoam or penetration oil down the cylinders and let it soak for a few days in case the rings are stuck on mine from sitting. My guess is that it sat untouched for all those years and anything that was shot into it when it was put away is long gone by now.

 

[Monark16]

Re: Help with 15hp Gamefisher (Force)

The 110 number is about what I saw in research. I found a 1998 mercury 15hp for sale that had 110 on the top and 100 on the bottom and they said that was good compression. Now granted they were trying to sell the motor but still I wouldn't be surprised if yours turned out to be ok. Thanks for the feedback. At this point i'm not sure if I should cut the cords and sell it or try to fix it. I bought it for $460 and put about $100 more into it. Any thoughts, please comment.

 

[freeisforme]

Re: Help with 15hp Gamefisher (Force)

I own several Chrysler/Force/Gamefisher outboards, I've got the 9.6hp Seaking/Chrysler which I bought along with a 1957 18hp Johnson motor, both were supposedly parts motors but I ended up only having to do minor repairs to get both running. I paid $50 for the pair of them, spend another $125 or so to get them running.
I have a 1975 15hp with electric start and tiller control that runs great, has 121/119 compression and was running just fine when I got it, I swapped a 10' Sears jon boat for it that was too small for me. I just went to look at another 1989 Force 15hp motor, same as my Gamefisher, in perfect running shape and it's compression checked out at only 105 per cylinder, it ran fine on the water and pushed a 14' flat bottom glass skiff along with me and the seller, about 500 lbs total, at about 18 mph or so. I checked the compression on that motor when hot. It pumped good water and looked great, plus it had a newer ignition system installed already. He was asking $300, he took $175, and I let him keep his fuel tank, I just took the hose end off. (He had just bought a new 20hp Yamaha 4 stroke and wanted to keep the tank).

There's a few others listed too, they seem to go pretty cheap even in running condition.
To me, the Chrysler/Force/Sears motors were always sort of a bargain, parts are generally cheap and easy to get, their not in high demand so they can be bought reasonable, plus, they're easy to work on.

The one thing that sticks in my mind is that my 9.6hp has 140+ on both cylinders, I don't see why a newer motor would run less compression?
Unless it was an attempt at running lower octane gas in later years?

If you did indeed overheat yours and that's the cause of the low compression, I'd want to take a look at the cylinders themselves and the headgasket. It could be as simple as a blown head gasket. You could also have heat damaged the rings, or completely scored up both cylinders. The fact that it still runs and both cylinders are close in compression readings tells me that it may not be a total or catastrophic failure. Most of the motors I've torn down that have been overheated have had one cylinder fail completely. Usually the top cylinder will starve for water first unless there was a total sudden loss of water supply from the pump.
Make 100% certain that both cylinders are firing, from what I'm finding out, these things have big issues with bad coils. Which I guess is why the common fix seems to be a complete change over to the newer ignition system or a CDI built ignition and external coil.

It looks like I'll be spending the $175 for the new ignition system kit for mine, plus a new impeller and t-stat just to be safe. The intention was to buy a parts motor but the motor I found runs fine as is, so I'm still looking at fixing the first one.

When I got my first Chrysler motor, I was told that most Chrysler motors didn't have as high of a compression reading as the OMC and Mercury motors did, but when I tested it, I got 145 on both cylinders. I was told that was way high and that my gauge had to be bad, I bought a new Snap On gauge set, it read the same. Then I bought my next two, both had about the same compression readings. What made me think twice with this 15hp was that it's the only Chrysler/Force type motor I've had with lower compression readings. If it were a older Johnson or Evinrude, I'd not have been the least bit concerned.

 

[Monark16]

Re: Help with 15hp Gamefisher (Force)

Thanks for the comment. I think i'm gonna have our mechanic take it apart and look at it. We'll see what the damage is and if we can get her back on the water. Thanks.

 

[reelfishin]

Re: Help with 15hp Gamefisher (Force)

After reading all the above posts, I pulled a few of those motors out that I had at the shop and checked compression readings just for information purposes, including one that I believe is brand new, never run. All are 1989 to 1995 models except one, which is an older very early Force motor still painted white. I believe that one was an 1984. The 1984 is a well used motor, but it still runs decent, it's compression read 111/117. The others were all right around 100 to 110 with one giving me only 88 on both cylinders. All of those run fine in the tank, I've not tried any of them on the water. The one new one is a Sears badged 15hp, 1989, still in the original box with no signs of every being started. That one gave me 109/108 on both cylinders. I cranked each one about ten times with some oil in the cylinders as well to lube things up as some haven't been used in a few years. If nothing else it was a reason to make sure they were all still OK back there. I'd sort of figure than 100 to 110 PSI is most likely the norm for the later motors, maybe the compression is lower due to fuel changes over the years? I do see that they ask for only 87 octane with no more than 10% of ethanol in the owners manual for the 1989 and newer motors. The older owners manual lists 89 octane. Although just a guess, this leads me to believe they lowered the compression over time to allow the safer use of lesser fuel.
I've also got a 1965/66 Chrysler 20hp, and a 1971 9.6HP as well, both of those give me just over 140 PSI on all cylinders. I have a 6hp Johnson from 1979, which I bought new, with less than 10 hours of light use on it and that motor has only 85 psi on both cylinders. It never had any more than that and always ran fine. On the other hand, my 1971 18hp Evinrude has over 160 on both cylinders and is so hard to pull start you need a glove or rag to grip the starter rope handle. I much prefer rope starting the Force or Chrysler motors as they seem to pull far easier than most others. I run a 1989 Force 15hp on my 15' aluminum boat, it almost feels like there's no compression but it fires on the second pull every time, it's never overheated, never not started and never let me down since I bought it back in 1992. That motor has 103/102 on both cylinders, has had a new impeller and thermostat every two seasons whether it needed it or not. I have a 9.9 cover on it to get by in local lakes with the 9.9 limit, and it gets used only a few times a year these days. It's probably only got a few hundred hours on it since new. I bought it from a former neighbor that was up in years and never used it much. When he did, I was the one that ran that boat, even when it was new.

It sounds to me like your going to have to pull the cylinder head on that motor and get a look, chances are you just got it hot and either stuck or heat damaged the rings. So long as the cylinders aren't scored, it should be an easy fix. If the cylinders are scored or the pistons burnt, then your most likely better off buying a fresh power head for it.
From what I'm told, Sears still sells a power head for that motor, but I believe its a later model unit.
There's a copy of the owners manual posted online here:
http://tinyurl.com/gamefisher15

I believe this owners manual was the same from at least 1990 on up for these motors. I don't see any real major changes over the years to these other than decals and which prop they came with out of the box. Most 1989 motors seem to have the two blade prop, most newer models came with a composite three blade prop.