Force 85 hard to start and won't run smooth

[kt4vq]

I just bought this boat. It has a force 85, 1989 model. I was told it just had a tune up and running fine. Long story. However, I tried to start it after pumping up the fuel bulb till it was hard. It took 20 minutes of trying to get it to start. I could get it to try to run but only for 5 seconds or so. I adjusted the idle screw to force a higher idle and got it to run for 3 minutes at 3,000 rpm before is sputtered out. I have fresh fuel. It will not idle at all. <br /><br />During the cranking of the engine it sounded like it was misfiring (popping out the exhaust not the carburetors). I pulled out the plugs and they were hard coated in carbon. A brass brush and 10 minutes of scrubbing I found bare metal. Now I feel a tune-up is in order. Any idea as to anything else like timing off, bad CDI, etc… ? Thanks for your help and feedback.

 

[eurolarva]

Re: Force 85 hard to start and won't run smooth

Did you push the key in to choke when you tried to start? If not that is why it was so hard to start. Buy new plugs and put them in. Are you sure you adjusted an idle adjust screw or was it a mixture screw. Is the screw on each carb on top above the choke?

 

[kt4vq]

Re: Force 85 hard to start and won't run smooth

Eurolarva, thanks for your reply. Yes, I was using the choke. This morning I replaced the fuel bulb cause I did not feel it was staying pumped up. After replacing it and tightening/replacing the sping clamps on the hoses it stays full. <br /><br />I did get it to run at about 2,000 rpm for about 30 seconds and then it would sputter. When it sputtered I would hit the choke and it would begin to run smooth again. I did this for about 10 minutes with the same thing happening over and over. So I thought the fuel pump might be bad.<br /><br />Before getting into the fuel pump I thought I might give it a compression check. Not good.<br /><br />Top = 25<br />middle = 120<br />bottom = 120<br /><br />So unless there is some magic little valve I need to look at it sounds like I have a bad clynder.<br /><br />Does anyone know anyone they recommend in the Atlanta area that might be able to rebuild/swope for a rebuilt?

 

[LubeDude]

Re: Force 85 hard to start and won't run smooth

I would do a decarb as per this post.<br /><br /> Decarb <br /><br />I would be surprised if you can gain that much compession, but its worth a try. These engines are known for being Carbon monsters and if the plugs looked like you say anything is posable.

 

[eurolarva]

Re: Force 85 hard to start and won't run smooth

Bummer on the compression numbers. The choke thing you did makes it sound fuel related however with that bad of a compression number on top you may have multiple things happening. Look at the spark plug on the number 1 cylinder. Is it clean or black. Chances are it is clean from steam cleaning it with hot water. If it is dirty maybe you did not have the compression tester screwed in all the way. If you cant keep motor running I would not do a decarb because you need to burn that stuff out of the engine and the only way to burn it out is to run the engine for at least 10 minutes.

 

[kt4vq]

Re: Force 85 hard to start and won't run smooth

Well guys here is the update. I got the Sea Foam and mixed the entire can with one gallon of fuel and a 50:1 mix of oil. I ran 1/3 of the gallon and let it set 5 - 10 minutes. Cranked it again and ran 1/3 again and did the process one more time until I used all of the fuel/Sea Foam.<br /><br />I then connected back the regular fuel and ran it for another 10 minutes. I then check all of the compression again and the numbers changed by maybe 1 - 2 lbs each.<br /><br />Now get this...when I have it running at 3,000 rpms it might run one minute and start to sputter and pop out the exhaust ...when it does this I can hit the choke for about 1 second and it will start to run somewhat smooth (far from perfect) and then it will start to sputter and pop again in a one or so minutes. By hitting choke again it once again will try to run somewhat smooth for about one minute again. This will keep happening as long as I want to hit the choke and keep it running.<br /><br />I pulled the plugs out and they all had carbon building up. The carbon was about the same on all of them.<br /><br />The compression again is <br /><br />top = 25<br />middle = 120<br />bottom = 120<br /><br />Man am I confused?

 

[kt4vq]

Re: Force 85 hard to start and won't run smooth

Oh and I forgot, there are no screws that I can get to on the carbs. They are all sealed. I am adjusting the linkage rod that controls the three carbs.<br /><br />Hope that helps.

 

[scotiany]

Re: Force 85 hard to start and won't run smooth

I think you should replace your fuel pump diaphram.

 

[kt4vq]

Re: Force 85 hard to start and won't run smooth

Does anyone know how many lbs of pressure the fuel pump should produce?<br /><br />Thanks.

 

[revertmastec]

Re: Force 85 hard to start and won't run smooth

Am I missing something. I would think that with the compression readings you have that is where you need to focus not on the fuel pump. I would tear off the head and see what it looks like inside.

 

[kt4vq]

Re: Force 85 hard to start and won't run smooth

revertmastec, I don't know if my thought process is correct or not but my reason to look at the other things like the fuel pump would help me to get the engine to at least run steady. The choke action made me think that there is other issues beside the compression reading. <br /><br />Are you suggesting that the low compression will cause the sputter and then the choke can smooth that out correcting the compression issue for a short period of time. I am confused as to why the choke will smooth thing down for a short period.<br /><br />I'm sorry I do not mean to be such a simpleton.

 

[dave in toledo]

Re: Force 85 hard to start and won't run smooth

if the compression is low, the fuel inst delivered properly sice it depends on the compression for the fuel pumps to work<br /><br />you have internal problems with that motor, rings, or head or exaust plate gasket, you have to look inside

 

[LubeDude]

Re: Force 85 hard to start and won't run smooth

Daves right, you have other issues to deal with. Could just be a head gasket and you need to figure it out before you dump more money in that engine. Also, I would have left the sea Foam in the engine overnight, I doubt that just 10 minutes would do much., but I think you have other issues anyway.

 

[eurolarva]

Re: Force 85 hard to start and won't run smooth

My point with the seafoam is that if he cant keep the engine running he should not use seafoam. It takes about 10 minutes of running the engine at WOT to burn that stuff out of the motor.

 

[kt4vq]

Re: Force 85 hard to start and won't run smooth

Ok I guess I will give the head removal a shot. I assume the bolts that in the head are the only concerns in order to remove the head.<br /><br />Is there any other surpises awaiting me once I back those bolts out?<br /><br />Guys, that you for the feed back on this issue.

 

[eurolarva]

Re: Force 85 hard to start and won't run smooth

Before you start pulling stuff apart you might want to get a manual. Most decent size libraries have these that you can check out. Either that or order one here at iboats. Click on mega mall and type force manual in search. Taking things apart without a reference is bad. The manual will walk you though the entire process.

 

[scotiany]

Re: Force 85 hard to start and won't run smooth

For the less than $10 and hours worth of work, I would change the fuel pump diaphragm. The way I was taught troubleshooting, you go from the easiest to the worst case scenerio. Tearing apart your head is not the first step of troubleshooting.

 

[dave in toledo]

Re: Force 85 hard to start and won't run smooth

even with a new fuel pump diaphram, if the compression is low the fuel pump wont function properly

 

[kt4vq]

Re: Force 85 hard to start and won't run smooth

Those of you that say the compression drives the fuel pump...does that mean the top clyinder drive the pump or all drive the pump?

 

[revertmastec]

Re: Force 85 hard to start and won't run smooth

I am not sure whitch cylinder drives the fuel pump. In my opion in does not matter. The fact remains that you have a bad cylinder that needs to be fixed. You can replace every part on that motor and it still will not run correct until that cylinder is fixed. Fix the compression issue then start to troubleshoot the fuel system and carbs.