My 'new' Force 40

[KeysJack]

Wow, what an awesome site, I have learned quite a bit reading the posts here.

So I was given a Privateer with a 98 40 HP Force that has been sitting quite a while, I shot some oil in the cylinders and cranked it up. I could only get it to run with my hand as a choke so I pulled off the carb and remarkably the inside looked perfect. I shot some wd40 through the passages, reassembled and replaced the dry rotted fuel lines. Cranked right up and idles perfectly.

I took it out for a test run and found it dies under load. I ran it for about an hour at 1/8 throttle and it never cleared out, but did run well albeit slow..

So I am going to order a fuel pump kit, carb kit and impeller. I was wondering what part number iboat carb kit I need for a sn: 0e332474 ?
I didn't check the inline filter in my rush to try the boat out, but I am going to replace it with a see through. It just occurred to me it could very well be the cause of my problem...

Another question I have is, how much lube does the lower unit hold, and where are the fill and drain holes?? The vent is clearly visible to me but that is it.

Last question, I realise this motor is probably small for an 18' boat,

I have seen talk that the 40/50 are the same motor besides the carb, so I was wondering if anyone has changed the main jet in a 40 HP for this one from a 50 HP (1399-6249 --JET-Main Fuel (click here) (.096) (0 - 1500 FEET))? http://www.mercruiserparts.com/showParts.asp?inbr=2532&bnbr=6&bdesc=CARBURETOR - 50 H.P.

I am thinking a few extra horses won't hurt for the $4 the jet costs...

Thanks for reading my long post!

 

[KeysJack]

Re: My 'new' Force 40

Well my impatience got the best of me, I ordered the 50 HP main jet, fuel pump kit, carb gasket set and lower unit plug seals from Mercury. It was actually much cheaper than I thought it would be. ($30 total) Couldn't bring myself to spend 20 for their impeller so I guess I will order it from here with some other stuff I am wanting. I am going to run it with the stock jet first and see if I get any gains..other than fuel consumption.

One advantage to being in Lauderdale is the ten dealers within 5 miles of the house and I can have them tomorrow. Hopefully this hurricane will steer clear and I can try out the boat soon again!!

 

[EricR]

Re: My 'new' Force 40

First off, nice looking boat, and the motor looks pretty clean.

Yes, looks very under powered for an 18' boat. But then again, you are in Ft.Lauderdale, and having lived there there ain't much waterway you are allowed to exceed a no wake speed in anyway. Frankly, I would be suprised if that 40 would plane the boat with more than one passenger in it. What is it rated for? I would expect to see at least a 90 on a boat that size.

 

[KeysJack]

Re: My 'new' Force 40

First off, nice looking boat, and the motor looks pretty clean.

Yes, looks very under powered for an 18' boat. But then again, you are in Ft.Lauderdale, and having lived there there ain't much waterway you are allowed to exceed a no wake speed in anyway. Frankly, I would be suprised if that 40 would plane the boat with more than one passenger in it. What is it rated for? I would expect to see at least a 90 on a boat that size.

Thanks. It is really hard to believe it is an 85 hull. Very strong and no soft spots anywhere. I keep it in the keys, so I will be running there most of the time. If it can make 20 mph I will be happy since most sites I go are three or four miles max. I am really looking forward to seeing how it does with all the new parts and spark plugs. I can't find the coast guard info for max HP yet

I have been looking for a lower cost project 90-125 HP at a decent price and I will probably repower it if it does well out at sea, and put the 40 Force on a 16 aluminum boat I also have.

 

[Frank Acampora]

Re: My 'new' Force 40

DO NOT CHANGE THE MAIN JET I repeat: DO NOT CHANGE THE MAIN JET!

While this is a Force that Merc has changed and I have little experience with them, Some things appear to be the same as the older Force engines.
It appears to be the same block and head as the older blocks, and it still has a Tillotsen carb.

These carbs are jetted for expected airflow at full throttle. The only time you change the jet is to compensate for altitude. DO NOT CHANGE THE JET! I have another lengthy thread somewhere on this forum explaining about carbs--Look it up.

Although the 40 and 50 appear to be the same, the extra horsepower usually comes from different compression and different port timing. Often the same block also has a different bore and stroke. A jet change or even a carb change will not give you 50 HP--probably only headaches.

 

[zoe'sdad]

Re: My 'new' Force 40

50 horspower force has different timing than the 40hp.

 

[KeysJack]

Re: My 'new' Force 40

Thanks guys, I was having a hard time believing just a jet change could be responsible for 10 HP. I really wasn't expecting much from it, that is why I didn't just buy a new 50hp carb for $100...


I suppose I'll have to look to NOS for a performance boost.

 

[eedwards]

Re: My 'new' Force 40

I would definitely get that 40 running then sell it and get the biggest motor you can for your boat.
I could be just me wanting more power,but my 15ft has a 90hp and i feel it is under powered and it the biggest i can put on the boat.

And Frank can you put a link for that thread i look up carbs and there is a lot of results to figure which one.

 

[KeysJack]

Re: My 'new' Force 40

I would definitely get that 40 running then sell it and get the biggest motor you can for your boat.
I could be just me wanting more power,but my 15ft has a 90hp and i feel it is under powered and it the biggest i can put on the boat.

I hear you, Their are some seriously good deals on outboards down in the keys, as soon as I find one I will be all over it. I have very little experience with outboards, but I can do most atc/motorcycle engines with my eyes closed, so with the right manuals and you guys i think I can restore/fix most anything on an outboard. I am surprised how simple they actually are.
I even think the 'choke' solenoid injection is innovative to say the least for a 2 cycle.

I actually like the idea of a transom extension and dual 90's since I have delusions I might just take this thing 20 miles + off shore if I like how it does in 3 to 4 footers.

I know i will never be taking four divers + 8 tanks with out a serious repowering...haha, luckily I am mostly solo and went all out with a DCS radio and two GPS's.

 

[Frank Acampora]

Re: My 'new' Force 40

Eedwards: I am the kind of a guy that doesn't remember what he had for breakfast so asking where I posted a thread is difficult to reply to. However, I did post one reply about carbs Oct 28 by Matthew A --adjusting air/fuel mixture. It has some basics on carbs there.

 

[Kajun37]

Re: My 'new' Force 40

have you done a compression check AND a spark check yet? before you go buy all kinds of parts these 2 tests should most definetly be performed...if you dont have a compression checker and spark checker..you can get both at autozone for $30-40 total....spark should be jumping a 7/16th gap.

 

[KeysJack]

Re: My 'new' Force 40

Well, cheapest and easiest is usually the answer...haha, I pulled the carb apart since they sent me 5 cork bowl gaskets for some reason..anyway, after cleaning it a bit better with a small copper wire and a can of carb cleaner it is running very strong in the garbage can. Going to take it out for a a test run in a bit and hope for the best. At least I have a spare carb kit and fuel pump now..

 

[KeysJack]

Re: My 'new' Force 40

Just back from my maiden voyage. Hit a respectable 26 (gps) MPH and easily got up on a plain, and did rather well in the 15+ knot winds and swells. Not much fun putting it back on the trailer with the high wind blowing it all over the place at the ramp, but hey I guess it is the cost of fun.