1999 Force 120hp on 2 cylinders

[gwag59]

1999 Force 120 s/n #OE361309, power only on cylinders 2 & 4, I've already checked compression all a little low but in the ball park, pulled the head - walls look good, replaced the head gasket, tried new fuel, checked spark on each with a screwdriver to ground & had a spark at a 1 inch gap, changed the plugs, switches coil inpt leads from cyl 1 to 2 & sparkplug wires from 1 to 2 still no power from cyl 1 cyl # 2 had power, same with 3&4, pulled to fuel pump apart & found no holes, (did not replace parts), changed fuel filter & it seems to stay full. The only common ground I find on the 2 cylinders with no power is that both cylinders are the top for each carb. Please tell me what to do next. (this also happened all at once)

 

[GT25]

Re: 1999 Force 120hp on 2 cylinders

I have a 1998 Force 120, and recently experienced the same problem. I have not yet resolved it, but I did notice the unburnt fuel on the plugs of cylinders 1 and 3 had a white color to it, so maybe water is getting into the cylinders. Have you noticed this on yours?

 

[gwag59]

Re: 1999 Force 120hp on 2 cylinders

No, my plugs have a dark oily look. I don't believe water is leaking into the cylinders because I pulled the head & everything looked good.

 

[lonewolf5347]

Re: 1999 Force 120hp on 2 cylinders

THE NEXT STEP I WOULD CHECK IS THE REED VALUES REEDS VALVES OPERATE IN RESPONSE TO CHANGE CRANKCASE PRESSURE,THEY ADMIT FUEL AIR MIXTURE INTO THE CRANCKASE THAT WILL GIVE YOU A LOSS OF POWER IN THE TWO CYLINDERS

 

[gwag59]

Re: 1999 Force 120hp on 2 cylinders

Thanks Lonewolf, I thought about that but didnt go there yet since both reed plate would have to have a problem. I think the top valve are for the top cylinders & the same for the bottom. <br /><br />Sorry but I can't help with your problem. Did you swap ignition parts between the four cylinders for any change?

 

[gwag59]

Re: 1999 Force 120hp on 2 cylinders

I just made a call to a marine repair shop & explained the above. His suggestion was fuel & suggested the reed valves. 1999 has four reeds & are $100 each. I asked if he thought it could be the pump & didn't believe it was. Unless I find another possibility I guess I'm taking my intake apart to check the reeds.

 

[lonewolf5347]

Re: 1999 Force 120hp on 2 cylinders

try www.seilermarine.com for reed's

 

[sony2001]

Re: 1999 Force 120hp on 2 cylinders

The carb jets are not blocked?

 

[gwag59]

Re: 1999 Force 120hp on 2 cylinders

Lonewolf was right on target.<br />I hope this helps anyone else with the same problem.<br />I pulled to carbs & reed assembly off & found one broken reed for cylinders 1 & 3. Each cylinder has four reeds each. The reed plate that holds the reed was also worn at the broken reed. Replacing the reed alone won't solve the problem. Hopefully it won't cost to much & I'll be back in the water soon. <br />The job itself was pretty easy unfortunately it waited for the nice weather to happen.<br />Thanks to all who replied. Someone else had the same problem & if you want more info let me know I'll check this board again.