1988 85hp Force , no power

[Rollie]

I am stumped . My daughter ran it out of gas . I filled it up , ran it to launch , loaded it and went 6 weeks till I started it again . Seemed to be running on all 3 cyl.s but would only go 25 mph with 36-38 normal . Have fixed puddle valve , cleaned filters , cleaned and adj. carbs , changed plugs , did the seafoam treatment , checked fuel lines , compression = 135 , 130 , 135 . The carb bowls all had fuel in them . All 3 plugs fired in the open while I did the compression test . The bottom is not fouled . It idles poorly and even though it seems to be running on all 3 cyls when I pull the plugs after 5 minuets or less of running , the top one is clean , the bottom one has a lot of oil on it , and the one in the middle has some oil on it . Whew , don't know where to go next . Anyone had this expirence or have any ideas ? Sure would appreciate any comments . Thanks Rollie

 

[12Footer]

Re: 1988 85hp Force , no power

first, when running the spark test, ground-out the other 2 plugs to prevent damage to the Thunderbolt ignition. But that's not important now. When you say top one is clean", how clean? Like new.? Like it has been steam-cleaned? If so, the top cylinder is getting water in it. This means a blown head gasket,cracked block (Very rare on this engine), or exaust port gasket or channel leak.<br />Pull the exaust port plate,and look for paths (discolored area at the gasket).<br />Let us know if you need more in depth info.

 

[Rollie]

Re: 1988 85hp Force , no power

Hummm , I'll check that as soon as I can get back to the boat . The top plug was clean , and dry . I looked into the cyls and the 2 bottom ones were wet looking but the top looked dry . Would it have as high a compression if the head gasket was blown ? It didn't skip at higher rpms , but was wide open ( I checked the linkage ) and sounded like it normally would at 1/2 throttle . Can't wait to check this out , will let you know . Super thanks ! Rollie rsmullen@vnet.net

 

[12Footer]

Re: 1988 85hp Force , no power

Remove a wet plug, and change it out with the top one. If the engine does a steam clening job on that plug also, it will remove all doubt,it's water. The compression is sometimes lower,yes...BUT, not allways. It would depend on where the leak was,and how big.<br />But your original post states that the top plug is clean. As water enters the hot combustion chamber, it truns into steam,and literally cleans the plug like new. As oposed to a healthy black coating.

 

[Backlash]

Re: 1988 85hp Force , no power

Hey Rollie,<br />Maybe you need to take that top carb off & clean it again. You're getting spark to, and have good compression in, the top cylinder. That would indicate a fuel delivery problem. When you cleaned the carbs, did you soak them in a solvent? Just spraying them with a carb cleaner doesn't cut it. It's worth a try IMHO. <br />Backlash

 

[Rollie]

Re: 1988 85hp Force , no power

wow ! Thanks for the responses , I really appreciate them ! I changed the plugs around several times , with the top plug always very clean when it came out , like it was new , But I cleaned them before I put them in . The top one came out dry and clean . I took the carbs all apart and cleaned everything . I could shine a small fiber optic light thru most openings and see that they were clean . There was a bit of debris in each of the carb bowls when I opened them up , so I could have missed somethin in the carbs. Will check there also . Will try to post some more tonight , heading to the boat now . THANKS again . Rollie

 

[sony2001]

Re: 1988 85hp Force , no power

ROLLIE you could be only getting spark to two cylinders. The third has its own CD unit or shares one with another cylinder. With 2 cyl. you will get 25 mph and a rough idle.<br />Use the SEARCH for Force 85 hp.

 

[ODDD1]

Re: 1988 85hp Force , no power

Rollie, you arent running on the top cyl...a clean plug means a dead cylinder....you did the compression, the fuel, and the spark check wasnt the best, should jump 3/8" cranking.....i have 2 ideas for you, a possible exhaust plate gasket that failed, will allow water into the exhaust chest and eventally back into a cylinder causing this prob, or a broken reed valve on #1 cyl....

 

[Rollie]

Re: 1988 85hp Force , no power

Thanks again for all the responses . Yesterday I looked at the top plug again and it had a oil film on it , so I didn't pull the head or the exhaust plate yet . I ran all new fuel line , replaced fuel filter , replaced fuel pump diaphragm & gaskets , disassembled the 3 carbs , cleaned and replaced . I put a dirty plug in the top cyl . I didn't get to put it in the water , but am heading that way now . If the top plug comes out clean , That should indicate the problem as I think I will have eliminated fuel as a problem . The flywheel is on the mark at tdc so I don't think the key is sheared . I think #1 & #2 run off the same cd and #3 is by itself . Some one told me it would be #3 the problem if a cd was bad . Not sure , will check the wiring . Really appreciate your comments , It is really helping me a lot .

 

[Rollie]

Re: 1988 85hp Force , no power

Back from the lake , it didn't run any better . The top plug was clean , so I pulled the exhaust cover . Could find no evidence of water getting in but I could see that #1 cyl has been washed with fuel . I thought the plug was clean , but I think it was fuel washed , cleaned , and just oily , and I missed the oil . Looks like fuel is getting in and out unburned . So whats left ? Coil ? maybe just a weak spark when I tested it ? Is that possible ? How can I tell ? I looked at the reeds when I had the carbs off and couldn't see anything out of order , But I didn't take them out . Wow , glad this is a simple engine , don't know what one would do with the new complex ones . I checked the wiring and #1 & #2 are on the same cd . So would that leave a bad coil , or could part of the cd be bad ? I understood the cd worked , or didn't , no inbetween , but don't know . Sure could use some more of your ideas and advice . Thanks again . Rollie

 

[Navigator]

Re: 1988 85hp Force , no power

Rollie,<br />Just for kicks, pull the plastic sheild off of the wiring harness on the side of the engine. Check to make sure that the wires are firmly attached to the studs and that no frayed wires exist. I had a similar problem on my old 1987 Force 85hp and it turned out to be a broken wire inside the casing. (I still cant figure out how ) Anyways, I respliced the loose wire and she ran flawlessly again.<br /><br />It's a long shot, but it wouldn't hurt to take a look before you start replacing electrical parts <br /><br />You've also probably done this, but you could switch the carbs around just to make sure it is not a fuel delivery issue.<br /><br />Nav.

 

[sony2001]

Re: 1988 85hp Force , no power

CD Output test;On #3 cyl. diconnect red wire <br />from CD to coil. With voltmeter AC 1000 Connect red meter lead to red CD lead. Connect black meter lead to ground terminal on the far left on the terminal block. Crank engine few seconds only and needle should swing.<br /><br />Other orange lead is not used on #3. For cheap repair you may try to get it to replace the work of the red one if found to be defective.

 

[Rollie]

Re: 1988 85hp Force , no power

Thanks for the ideas , will try them this evening . Thanks , Rollie

 

[Rollie]

Re: 1988 85hp Force , no power

checked all wiring for breaks , etc. , changed #2 & #1 coil around , cleaned all grounds , ran it, no improvement. #1 looks like it is getting fuel . Will do cd test tommorow . Could bad reeds do this and still give a good compression reading ? Thanks for your ideas , Rollie

 

[12Footer]

Re: 1988 85hp Force , no power

Everything is pointing to the CD Pack.<br />You have ruled-out the coils. But, back to that plug...Does it actually CLEAN a black plug? I'm still concerned about a jacket leak.<br />Do the test Sony laid out. We need to rule out the pack.<br />If the reeds were stuck open or closed, you would have zero fuel in #1.<br />You might also get an "exhale" out of the throttle body when it compresses #1, if the reed was broken or stuck open.<br />I know it would have to be a coincadence,that she ran her outta gas, and the pack went south...But it's beginning to look that way.

 

[Rollie]

Re: 1988 85hp Force , no power

12footer ,sony , and others , you've got it ! I switched the cd's today and guess what ? #1 (&#2)run fine ...#3 is dead now ...same cd circuit that was hooked to #1 when it wouldn't run . and it will throw a nice spark in the open .. just not under compression . I went to a Force graveyard and got a used one , but it was bad also . Think I will try the unused #4 circuit for the #3 as it ran the #2 cyl . I am checking the wiring as I know it has to be wired correctly to work . Wow , everyone on this board is SUPER ! I cannot thank all of you enough ! An experienced person has made many mistakes , an expert has made them all ..I am now experienced , on my way to being an expert ! Thanks again ! Rollie