1990 125hp Force motor lower unit oil change

[MississippiSteve]

I have recently purchased a pontoon boat and it has been slightly neglected over the past few years, I own a bass boat with a 50hp johnson and am not completely in the dark, but until I can get a manual I will have to rely on the kindness of strangers to answer some of my questions.<br />The lower unit has a vent and fill screw but I am not positive the screw at the foot is a drain port, any suggestions?<br />The prop was replaced with a smaller prop (50hp force was what I was told, how drastically does this affect rpms? The motor acts erratic at 6500 rpm (may need the high speed jets cleaned) but holds speed steady up to about 5500rpm.any suggestions appreciated.<br />At times the engine shudders when accelerating, after letting off the throttle and trying again it usually smooths out, does not act like its slipping.<br />What does the dash gauge that says "water" and is graduated from 0-15 measure? it does not seem to move much. <br />Finally my last stupid question for today, how much water volume should one expect to see from the water pump? <br />I like to err on the side of caution before tearing blindly into things or ignoring symptoms so any and all help will be greatly appreciated.

 

[Hooty]

Re: 1990 125hp Force motor lower unit oil change

Twistin' that engine to 6500 is a might tight Steve. Something in the neighborhood of 5500 should be max. You definitely need more prop.<br />The gauge that sez "Water" is a water pressure gauge. It measures pressure from the water pump. Get yourself a shop manual for that engine and replace the water pump. The manual will also answer the question about the lower unit fill and vent plugs.<br /><br />c/6<br /><br />Hooty

 

[Charger183]

Re: 1990 125hp Force motor lower unit oil change

The recessed screw holds the shifter fork in place. Bad move to remove it....

 

[Charger183]

Re: 1990 125hp Force motor lower unit oil change

Use a 17" or 19" pitch prop. Best of luck.

 

[MississippiSteve]

Re: 1990 125hp Force motor lower unit oil change

I had a feeling the bottom screw was not a drain plug - it was just too small and didnt seem appropriately placed. I'll wait for the manual on the proper procedure so I just topped it off.<br />I called the " Prop Doc" today and he says he can fix me up for about $130.00, so that will work.<br />In talking with him I found out that the cavitation plate somebody installed is useless on a pontoon boat and I'll be taking that off directly. I believe it and the smaller prop have been churning too much air and causing the shudder, I've had to keep the motor trimmed all the way down.<br />Starter quit this weekend (PTL for a recently stowed pull rope), my local starter repair mechanic says he can repair it but to try a little WD40 first, if not i'll be taking it to him first thing next week.<br />The water pump is working but I'm not sure the gauge is , just in case I will put a new impellor in to be sure, a Johnson's "peeing" sure makes things easier to tell.<br />I'm going to try to find one online first, should be able to order one locally if all else fails.<br />If you have any other suggestions feel free , I really appreciate the help , it helps validate my own hunches. Thanks again , Steve.

 

[MississippiSteve]

Re: 1990 125hp Force motor lower unit oil change

WD40 does a great job, starter is working fine , just had to free it up, may come in handy for another boater who's starter spins but won't kick in.

 

[Hooty]

Re: 1990 125hp Force motor lower unit oil change

Hey Steve, <br />You may know this but a lot of folks don't, that NAPA handles marine parts. If you ask, they may even give you a marine parts catalog. Saves them the time looking up part nrs.<br /><br />c/6<br /><br />Hooty

 

[MississippiSteve]

Re: 1990 125hp Force motor lower unit oil change

Thanxs Hooty,<br /> I'll check with them in the morn, I didnt know they had access to marine parts (although I do buy my tractor parts there).<br />I have a hunch the water gauge is either not wired or is wired to the wrong type sending unit, on the motor I cant seem to find a sensor that corresponds with a water pressure, there is a temp sensor and I dont have a gauge for that, ( the boat is an '88 model and the motor is a "90 model) and I have discovered other minor mistakes that someone has made in the dash wiring (probably when the boat was renovated)

 

[Hooty]

Re: 1990 125hp Force motor lower unit oil change

The water pressure gauge won't have a sending unit. It will be a piece of tubing teed into the water line going to the tattle tale (pisser).<br /><br />c.6<br /><br />Hooty<br /><br />...unless that's a water temp. gauge.

 

[MississippiSteve]

Re: 1990 125hp Force motor lower unit oil change

It seems the previous owner has "steered me off course" , I bought the new prop today and it didnt fit. I did some backtracking and if I am understanding the model number right I have an 87 model motor (model# 1258F7B serial # 1502).<br />So tomorrow armed with the new info the prop shop should be able to fix me up.<br />After browsing other other posts I noticed that my motor has a mix of blue and black coils which appears to be a "no no", I'm not sure how how critical that is but will have to investigate further.<br />Napa couldnt put their hands on a Force manual but suggested Books-a-million.

 

[nydoug]

Re: 1990 125hp Force motor lower unit oil change

My 1988 125 HP Force appears to have to fill/drain ports for the lower unit side by side instead of top and bottom does anyone know why?
Thanx
NYDOUG

 

[headows79]

Re: 1990 125hp Force motor lower unit oil change

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