Force 1998 /120 HP, if it isnt 1 thing, it's another...grrrr

wild n crazy

Seaman
Joined
Oct 20, 2008
Messages
68
agrrrrrr, I have finally changed the impeller, rebuilted the fuel pump, notice the gear cable cracked and broken...replace it.took the lower unit back out and readjusted the gear and the shifter, and and the cable, before all this, the water didnt pump out of the peehole, the engine wont idle or start in the water, after the adjustment, it started and the 1st run..water circulating through the peehole, runs good, then came to the shallow water part. the prop rubbed agaisnt rock, dent and bend, going back it's all good. the next trip out, the boat wont speed up. took the prop to the part dept...he say that the prop is not for the 120 Force, how can that happened? it was running good until I hit bottom, then I've noticed that the prop it's wide like the part personel said, and it have a trace like it's been roughing against the topedo ring. so the part p. traded and ring between the prop and the shaft. which bring the prop out away from the topedo about a 1/4 inch. but still not running well, this timeI've notice different engine noice, can any one help me , I love to do this repairing, because the learning and the challenge . sorry for the long post. Thanks all in advance
 

brianvolt7

Chief Petty Officer
Joined
Jun 7, 2008
Messages
423
Re: Force 1998 /120 HP, if it isnt 1 thing, it's another...grrrr

:eek:Holy cow!!!!! It sounds like its ready to explode!!!:eek:
If you don?t get the answer soon on these posts you may want to look this part up on the iBoat website to make sure you actually have the right prop and bushings. I have a 1990 force 120 and my prop is not quite a ? inch away from the housing. I think all of us have ?hit rock bottom? with our boats at some time.:)
 

wild n crazy

Seaman
Joined
Oct 20, 2008
Messages
68
Re: Force 1998 /120 HP, if it isnt 1 thing, it's another...grrrr

Thanks Brian, rebuying the prop is a must, but still I need to know why all of a sudden the speed is lost, I have been told that the prop belong to a mercruiser..but the thing is that the boat has been running good until then, and also I forgot to post is that the rpm is also high, can some one please tell me what do I need to adjust? thanks
 

LSUtiger

Recruit
Joined
Aug 20, 2009
Messages
5
Re: Force 1998 /120 HP, if it isnt 1 thing, it's another...grrrr

If I understood you correctly, the prop wore into the lower unit housing and now there is a gap between the housing and the prop? (I've had that happen before when I hit an object in the water and the prop jumped forward. Apparently the thrust washer was not correct.) The gap you have now allows exhaust to escape through the gap and exit in front of the prop blades. This disrupts the water flow over the blades, causing higher RPMs but less bite. My2cents
 

wild n crazy

Seaman
Joined
Oct 20, 2008
Messages
68
Re: Force 1998 /120 HP, if it isnt 1 thing, it's another...grrrr

Thanks LSU, that's exactly explaned to me when the part sellsman told me that my prop is for a mercruiser, and it's diameter is larger than the housing, which it's almost true, because it almost same diameter from the prop to the housing..I think what you've mentioned about the thrust washer is not correct, that's why the prop rubbed the housing, then the part sellsman traded me one of his, but it's much thicker that's why it came out to a 1/4 inch gap...you've explained well, maybe it will fix my problem, thanks LSU...I'll try to fix that when I have time
 

brianvolt7

Chief Petty Officer
Joined
Jun 7, 2008
Messages
423
Re: Force 1998 /120 HP, if it isnt 1 thing, it's another...grrrr

I would go to iBoats and buy the correct prop. Get the entire kit for your boat that will have the exact prop, thrust washer, bushings etc specifically for your boat motor. This is the only way to eliminate this as the problem. You may destroy your lower end using the wrong prop.:eek:

GOOD FISHING TO ALL
 
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