Force 150 pros and con's

Shifflett115

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Jun 11, 2007
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What's up everyone , I'm looking at a late 80s early 90s force 150 , just wanted to know the pros and con's of the 150s . I have an 1985 force 125 that is billet proof , we wakeboard , tube bahind all summer and its great but if the 150 checks out it would just be more power , what does everyone think of the 150s?
 

Frank Acampora

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I used to think it was a schlock engine---until I got one. It came in a couple of versions:1. An earlier model, small bore (3.3125) with either small WB carbs or large TC carbs. and 2. A big bore (3.375 version with large TC carbs. I have it from a good source that the stroke was 2.875 but have never measured it myself.

I have both the small bore/big carb version and the big bore big carb version. I have not yet run or water tested the small bore but I can tell you that the big bore version with dual exhaust will make your 125 look sick. For example: On my 21 foot cuddy cabin a 125 topped out at 33 MPH. With the 150 the same boat tops out at 40, even with the significantly increased weight.

Although the 150 uses the same mounting bolts, mounts to the same
midleg, and uses the same spline pattern on the drive shaft. It is far and away a better design. That massive plate on the exhaust side hides tuned exhaust runners.

The only problems I have heard about them are that the top semi-keystone ring tends to break. Indeed, Both engines I bought (cheap) had two pistons needing replacement. I have also heard but never experienced that they MAY POSSIBLY break the crankshaft.

Since it is a 5 cylinder in line, water needs to be pumped high and it needs a LOT of cooling water. The water pump is the same as for the 3 and 4 cylinder engines so you should pay particular attention to the impeller and change it on a regular basis as scheduled maintenance. An old impeller will cause the engine to overheat
 

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HotTommy

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Mar 15, 2013
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Frank knows his stuff. He helped me replace one piston with a failed ring on my '93 Force 150. I'm now faced with doing the same job on two more. My intent is to replace all the original pistons this time. Unless you are willing to take on the task of changing out the pistons, I'd be wary of the 150.
 

jerryjerry05

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May 7, 2008
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How early??
The first run of 150's had exhaust problems.
They were reported to have fixed the cooling/exhaust.
The 150(my opinion) needed a bit more oil mixed with the gas to stop the ring failures.

The 150 was touted as the best HP to weight for any engine when it was introduced..
 

Shifflett115

Petty Officer 2nd Class
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Jun 11, 2007
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191
Thank you guys for the input, frank you helped me replace a piston in my 125 years ago , the 150 I'm looking at has the dark gray case with silver and red stripes on it but the oldstyle lower unit .I don't know if its the early or later model I'll find out tomorrow , what year did the change the bore size ?I was planning also on putting the 2:1 lower unit on it , would the lower unit take the power ?
 

Frank Acampora

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I really don't know if the 2-1 lower will take the extra power. The gear teeth are relatively small and we are talking not only a lot more power than the old Chrysler engines but a lot more torque. A better alternative, if you can get one cheaply or if you already have one, would be the later Force lower units with a 1.93 to 1 ratio. The gears are much stronger. IF the engine has a 2 piece drive shaft, it already has this lower unit.

I think the small bore engine was only made for about two years, something like 89-90. Unfortunately I do not have my Wiseco book which tells exactly which years took what pistons.
 

Shifflett115

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Jun 11, 2007
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Thank you for all the info , I will know more about it tomorrow , year ,ect . If I get it I'll run a compression test . apparently it hasn't been ran in several years , I'm hoping all is good
 

Shifflett115

Petty Officer 2nd Class
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Jun 11, 2007
Messages
191
From reading the books and looking up parts ,it looks like in 91 they went to the bigger bore on the 150s . I hope everything checks out because my 125 is a small bore motor
 
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