120 hp 1985 v4 wont idle and hard to restart

slim433

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Joined
Aug 15, 2010
Messages
18
I have bought a bout with a 1985 120 hp after getting everything put togather the engine won't idle it will start with the start lever up but if u move it down at all to keep the engine from screeming it will shut off and will not restart . Not sure what's up I did compression and 3 are right around 120 and the other is like100 . Any help would be a help thanks slim
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: 120 hp 1985 v4 wont idle and hard to restart

Check
Compression
Spark
Fuel delivery
Spark plug condition
Most likely the carbs need a good service though.
Welcome to iboats.
 

slim433

Cadet
Joined
Aug 15, 2010
Messages
18
Re: 120 hp 1985 v4 wont idle and hard to restart

thanks for the reply. it has 120 on 2 cyl 118 on 1 and 99 on the othere but it been sitting for awhile by the way it looks so i am hoping that one will come up some after it runs for alittle . the plugs are new and are the same as the ones that came out. vro is bypassed and fuel is mixed 50.1 but might be closer to 40.1 i mix heavy handed . i am going to put a fuel filter and primer bulb in it tomorrow. i have been a truck and refer mechanic for over 20 years but this is the forst boat motor i worked on and they are not like deisel engines in anyway..lol. the bores look smooth and clean and pistons have little to no carbin on top of them looking in from the plug holes. i think i need to do aspark test to make sure the coils are working and maybe test the cdi box .let me know your thought if i could get thisin the water tomorrow before my son leaves for afghanistan for ayear i would love it . him leave is done on sunday so please help ...
thanks
slim
 

slim433

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Joined
Aug 15, 2010
Messages
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Re: 120 hp 1985 v4 wont idle and hard to restart

my boat is a 1987 bayliner carpi cuddy in desent shape for it's age seat are still good soft spots in the cuddy and in the storage under the rear seats other then that floor is hard . this is my first boat and i want to fish and pull the girls and my wife around with it. we are lucky we only live 1 mile from the susquehanna river . soit would be great to get this running .. thanks again slim
 

keefallan

Petty Officer 1st Class
Joined
Jun 23, 2010
Messages
219
Re: 120 hp 1985 v4 wont idle and hard to restart

Take the carbs apart and give them a good cleaning. Make sure to run a piece of soft metal wire thru the idle passages. You might be suprised what you get out of them. Heck, I'd do it just for the piece of mind to know that you've gone through them and they are now not part of the problem(if one still remains). Also, I'd decarbon the cylinders. That might help with your low cylinder.
 

tal

Petty Officer 1st Class
Joined
Nov 21, 2003
Messages
214
Re: 120 hp 1985 v4 wont idle and hard to restart

I have the same motor so I'll share some pointers with you.

First make sure the red lever of the choke solenoid is pointed down. If it is moved anywhere from that position your engine will flood and be hard to start.

When you do the carbs make sure you clean the idle passages underneath the little metal side panel. It's hard to see what you're doing in there and probably the hardest place of the carb to see if you got it cleaned. I used a bright led light and could see the passage was clear. Careful not to overtighten the plastic carbs for obvious reasons, plus you can squeeze the gasket out. Link and sync per manual. It will idle a little high on muffs from not being in the water with back pressure.

Make sure all the lines are tight on the aftermarket fuel pump, especially the one picking up pulse from the crankcase. Just make sure there are no leaks in the fuel system.

The pee stream on this motor isn't the strongest but main thing is you have water circulation. Might want to check the vernatherms, I had one stuck open.

Once you get it running, check your WOT timing and make sure the timer base is not stuck and moves all the way to the stop point. This gave me some grief on my motor.
 

slim433

Cadet
Joined
Aug 15, 2010
Messages
18
Re: 120 hp 1985 v4 wont idle and hard to restart

Thanks guys for all the info I will work on it today and see if it will get going. I got the manual by download on line that covers like 73 to 90 something and if I find out what was wrong I will let u know. You guys are a life saver thanks again.

Slim
 

slim433

Cadet
Joined
Aug 15, 2010
Messages
18
Re: 120 hp 1985 v4 wont idle and hard to restart

Hey guys well I got it to idle and it ran fine at home hooked to a hose but when I droped it in the river it started and stalled when backing out. Restarted and did the same thing then it wouldn't restart till I trimed it out of the water and would shut down when the trim was droped back down. Is there some thing that would keep it from breathing with the exhuast underwater. It seemed like with the prop out it would start and once the prop went under it would cut out. Did have a fuel leak coming out of the carbs when trimed out of the water. But that could be a sticking float needle. Would be thankfol for any input at all on this. I am starting to think it may need rebuilt.

Thanks
Slim
 

tal

Petty Officer 1st Class
Joined
Nov 21, 2003
Messages
214
Re: 120 hp 1985 v4 wont idle and hard to restart

Some fuel seepage out the front of the carbs while trimmed up is normal.

Sounds like you need to up your idle a little but best to do once you get it warmed up and in gear. Also, as you mentioned, if trimming up and down affects the way the engine runs you probably have a float issue in one or more carbs.
 

slim433

Cadet
Joined
Aug 15, 2010
Messages
18
Re: 120 hp 1985 v4 wont idle and hard to restart

Guys thank you so very much for all your help. It was the red lever on the choke that was messing my life up it was up not down. When I flipped it and started it the idle was way high cuz of the adjustment I made to get it to idle set idle down then it idle very smooth and no smoke at all shifted both way and reved to wot on muffs with no hassitation at all. I think my wife may let me live now lol. Again thanks so much you guys are great.

Thank you
Slim
 

slim433

Cadet
Joined
Aug 15, 2010
Messages
18
Re: 120 hp 1985 v4 wont idle and hard to restart

Ok I got the boat in the water today. Had trouble with keeping it running at the dock but made some adjustment and we made it out on the water the motor did great in open water just cruzing and it wot man it was pretty fast. After we dock I went to move it back on the trailer and the throttle went wot and I hit the dock with the back of the boat nothing damaged thankfully. Something happendbin the controll box so I have to look in side to find out what. And shifting it grinds a lot . Could the dogs be wore out?

Thanks slim
 
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