'90 Force 150Hp won't pull

[wdwalt]

Hello everyone, I just stumbled on this site trying to resolve my boat problems. I have had this Force 150 for several years and it has done faily well. It has ran faily well the last few weekends although it stalls when going into gear and hasn't been idling very well. I bought the repair manual and thought I had improved the idle last week by adjusting the idle mixtures and then the idle speed. Now it won't pull over about 25 mph. It doesn't rev like it should when I give it WOT in fact, it only gets up to about 3500rpm. Lookiing at the book, I am really puzzled and thought I would give up and take it to the local boat place but they have a 2 week back log. Can anyone offer some direction? I just replaced plugs and checked the full filter and pump, it seems to be clean.

 

[Frank Acampora]

Re: '90 Force 150Hp won't pull

Whenever I hear "I adjusted the idle mixture" I begin to get worried. Adjusting them too lean will improve the idle, but it really messes up the engine. When you hit the throttle from a stop, (hole shot) if the engine "sags" and almost dies, then picks up again, it is too lean. Also, running too lean on all three carbs can affect power and top speed but it can also melt pistons. NEVER--NEVER--NEVER adjust the mixture needle to leaner that 3/4 turns out from lightly seated. No matter how poor the idle and no matter what the manual example is. 7/8 turn is preferable and some of these engines like 1 turn out.

Logic indicates that if the engine was running well before and recently developed a problem, the carb adjustment is not the problem. Low speed idle mixture screws do not magically go out of adjustment by themselves. The first impulse of most owners is to fiddle with the carbs and in reality, this should be the last thing to adjust.

Too low and idle speed will give a poor idle and stalling when put in gear. The four cylinder engines usually need about 700-750 RPM in gear in the water-about 1,000rpm in neutral. The 5 cylinder 150 is probably about the same.

Replace the diaphragm in the fuel pump as they get hard and go bad after a while. Check the entire fuel system to be sure there are no clogs or restrictions. and then check each plug to be sure all are getting spark.

 

[wdwalt]

Re: '90 Force 150Hp won't pull

Thanks for the response. I appreciate the concern over getting the carbs too lean. I actually started by setting them the recommended 1 turn out from lightly seated and then went 1/8 right until idle changed then 1/8 left until idle changed and ssplit the difference, as the book suggests. In fact, I ended up at 1 full turn out on all three carbs, right where I started from. The idle speed adjustment did seem to help the idle after that, although it still will not go into gear from idle and keep running without going in fast and giving some gas.Obviously not the best for tryoing to dock. The more I read, the more I suspect the throttle linkage. When I push the throttle forward I really only get any response at the last 1/4 of the travel upto max throttle. I have not yet tried to rev it by hand at the motor but I though that would be next. Maybe I can at least isolate it to that. Any thoughts on adjustment? As for not dying when put into gear, do you think it could be the timing advance?

Thanks in advance. (no pun intended, but funny)

 

[roscoe]

Re: '90 Force 150Hp won't pull

Don't mess with the timing.

Check the compression.

Check the spark.

 

[wdwalt]

Re: '90 Force 150Hp won't pull

Thanks, I just just ordered the fuel pump kit I thought it couldn't hurt to have it rebuilt. I will get the compression and spark checked too. I did find that the terminating point of the throttle remote cable at the motor was loose and allowing some play in the cable. I tightened that back down. I think part of my idle problem may be that I was trying to get the 700-800 rpm in neutral. I was worried that having it to high could cause damage to the transmission when going in gear. Taking it up to 1000 rpm should help. Thanks for the caution on timing, I won't mess with it.

 

[Frank Acampora]

Re: '90 Force 150Hp won't pull

It's not a transmission per se. It is a Dog Clutch and is not designed to slip at all. Contrary to what you might think, it is best to give the handle a quick snap forward for about 1/4 to 1/3 of the total travel to get into gear. If you "ease" it in, you will hear the dogs rattling against each other and you will be wearing them. Should go into gear with a slight "clunk" The control box is designed so that for that first travel, the throttle will not advance.

 

[wdwalt]

Re: '90 Force 150Hp won't pull

Thanks, that does make sense. I don't know if I have narrowed down the problem or not. Today I went through the plugs and I have spark at all 5. I pulled the fuel pumps and although the diaframs seem pretty brittle, I do not see any obvious holes or tears. I did find that there was a pretty significant amount of varnish and particles in the bowl and main fuel jet of the lower carb. I got that all cleaned up and back together. Now I'm just waiting for the fuel pump kits to be delivered Friday. Hopefully I have accomplished something.

 

[QuadManiac]

Re: '90 Force 150Hp won't pull

Even if it doens't eliminate your current problem, it will forestall future ones!

 

[wdwalt]

Re: '90 Force 150Hp won't pull

Hello everyone. the fuel pump kits showed up yesterday and I got them done and back on. Although I have not yet had the boat in the water to see what really happens it sure seems to run smoother in the test tank. It fired right up and was idling much faster than it was before I took the pumps apart and cleaned the main jets on the carbs. I adjusted the idle down to 1000 rpm in neutral. I put in gear briefly and it did not die, the idle dropped down by about 2 or 300 rpm but kept going. Of course, I couldn't rev it too high in the tank but I'm pretty excited about getting the boat in the water on Saturday. Thanks to all three of you for your feedback and advice. I'll let you know how things go on Saturday. I just picked up an inline fuel filter to add to the fuel line too. I don't want to have this problem again.

 

[wdwalt]

Re: '90 Force 150Hp won't pull

Well, I guess this will be the end of this thread. It is definitely the end of the motor. We had the boat out yesterday for the first time since cleaning the carbs and rebuilding the fuel pumps. It ran VERY smooth and did very well for about 6 hours. I ran about 25 gallons of gas through it skiing and sight seeing around the lake. On the way back to the boat ramp to leave, there was a big pop followed by a grinding noise. When I pulled the motor cover off, the fly wheel was just laying on top of the motor. The main shaft had broken just below the flywheel. Obviously, it tore up everything around it as it spun free on top of the motor. I believe this one's a goner!

Thanks to you all for the help with my other issues. I have no idea what could have caused it.

 

[newbie4life]

Re: '90 Force 150Hp won't pull

It's a sick feeling, isn't it?

I know EXACTLY that feeling in the well of your gut. At least you have an outboard, and have a few options.

I have an L-Drive (found out what it is, AFTER I bought it, rather than BEFORE.) Oh, well, live and learn. I had it rebuilt, and will sell it in the spring of the year... I think... Yeah... Well, we'll see.

At least I'm decisive. Kinda.

Anyway, I feel for you... I really do.

 

[baxtr]

Re: '90 Force 150Hp won't pull

Very sorry to hear that Wdwalt, 2 people on ebay parting out their 150's, crankshaft and all, maybe you could fix it up, or at the very least, be the 3rd ebayer parting out a 150 and get some money out of it plus help someone else get back on the water. I would assess the damage first, to see what all got damaged.

Sad ending, I was looking forward to a happy one.

 

[wdwalt]

Re: '90 Force 150Hp won't pull

Thanks for the sentiments. I have checked e-bay and see some parts for an 89 Force 150hp power head. I am temped to try this myself over the winter provided I can get the cam shaft reasonably. What do you think, is this something that I can do without taking the motor off of the boat or do I need to plan to get it down and set up a stand? Although I have a decent supply of tools I don't have a great amount of space to work.

In the end, every boat shop that I have called says that a US Marine Force is not worth re-building. I on the other hand would spend a few hundred dollars and lots of my free time intstead of Many thousands to re-power. Any thought? The boat's pretty old so I don't want to put too much into it but couldn't really afford to replace it right now.

 

[baxtr]

Re: '90 Force 150Hp won't pull

You will have to pull the powerhead off , but leave the rest attached to the boat. I rebuilt mine on a 4 foot table. Take lots of pictures as you dismantle it, bag and lable all parts, and it'll go back together easily. I rebuilt my 125 last winter, never touched an outboard motor before, and it purrs like a kitten now, it was Very easy to do. My deciding factor was that it cost me 500 bucks to rebuild it and not thousands for a new motor (I overbored 2 cyl and honed all 4 , new pistons in the 2 overbored, new rings in all, new gasket set). My local boat shop told me the same thing.


Will you be doing anything else other than the crank?





Before:

After:

BTW I lifted my 125 powerhead off by hand......very heavy trying to get it off of a ladder, I would recommend you use some sort of hoist, especially seeing as your 150 will be heavier.


Here is my makeshift hoist I used to re install:

Lot's of help here on the site if you need it.

 

[wdwalt]

Re: '90 Force 150Hp won't pull

Thanks Baxtr, You are making this look really tempting. I just may have to try to pull this off.

Frankly, this whole IBoats forum is terrific. Real help from people that have been in the same position.

Thanks again to everyone. We'll see how the e-bay bids go.

 

[baxtr]

Re: '90 Force 150Hp won't pull

Good luck, let us know if you need any help.

 

[wdwalt]

Re: '90 Force 150Hp won't pull

OK, I'm back for some more advice. I have been watching the parts I need; camshaft, flywheel, and ignition on e-bay. 3 days to go on the auction. In the meantime, I have found a used '89 150 that has a broken skeg and also a place that will sell me a rebuilt power head. Obviously, the power head is the most expensive. Do you think I should try to get the used '89 and try to swap my lower unit or go for the power head if I can't get the parts. As for amount of work, is it easier to swap a lower unit rather than trying to replace the camshaft or replace the whole power head?

Such decisions!!!!

 

[MikDee]

Re: '90 Force 150Hp won't pull

By the way, It's a crankshaft, not camshaft, there is no camshaft in a 2 cycle engine! Well, You'll have to remove the lower unit, to take your engine apart to get the crankshaft out, So that should answer your question. It may be cost effective to just get the used motor, and just swap the lower units, it depends on the price, & condition.

 

[wdwalt]

Re: '90 Force 150Hp won't pull

Thanks for the correction. I guess camshaft demonstrates my experience with overhauling outboards...none!

My worry was messing up the lower unit by trying to swap it out. I guess it it has to come off either way, buying a working motor may be the simplest way through this. Worst case, it I do have to rebuild one, between the two I would have all of the parts, including the crankshaft.

Thanks again.

 

[QuadManiac]

Re: '90 Force 150Hp won't pull

Be aware that my manual does not show an '89 150... the 150 doesn't appear until the '90 year. The 1990 90hp has two models, early on a 124 and later a 128.6 cubic inch power head, shared through 1994. Where did you find this '89 150?

Good Luck!