Force 125 won't rev over 4000rpm

Matt Harper

Cadet
Joined
Feb 23, 2006
Messages
17
I just installed a new water pump on my recently acquired 87 Force 125. The motor starts and runs fine - except - that according to the tach on my old barge of a Bayliner Trophy, the motor revs out at around 4000rpm. My Seloc states max revs are 5000rpm - so I'm a grand down. I'm definitely running on all four, with sufficient cooling and the correct prop.<br />Will a de-carbon be the miracle cure (who knows when it was last done - but it does have new looking plugs) - or should I be worried about more serious potential problems??
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,753
Re: Force 125 won't rev over 4000rpm

Decarb is always a good idea.<br /><br />How do you know it is the correct pitch prop?
 

Matt Harper

Cadet
Joined
Feb 23, 2006
Messages
17
Re: Force 125 won't rev over 4000rpm

Good Question! The guy who sold it to me said it was the original. I'm assuming again, aren't I!
 

roastinears

Seaman Apprentice
Joined
Aug 26, 2004
Messages
36
Re: Force 125 won't rev over 4000rpm

you might also check and make sure you tach is matched to the motor. some tachs can be changed to match different motors. might have two poles, another four. when i got my boat second hand i could never get over 3200 rpms and found out motor was just fine, but someone had put a tach on that could not be matched to the motor.
 

howeird

Cadet
Joined
Oct 22, 2005
Messages
15
Re: Force 125 won't rev over 4000rpm

I was having a simslar problem and decarbing made a big difference. I get 5200 at WOT.
 

javsam

Chief Petty Officer
Joined
Aug 24, 2005
Messages
421
Re: Force 125 won't rev over 4000rpm

good point on the tac match up tom, you need a tach for a 24 pole alternator.<br />javsam
 

jastacey

Petty Officer 2nd Class
Joined
Jan 25, 2004
Messages
173
Re: Force 125 won't rev over 4000rpm

I believe Teleflex still makes a tach for the Chryslers/Force motors, when I had a Force motor, a few years back I bought one ....because the boat didn't have one
 

Matt Harper

Cadet
Joined
Feb 23, 2006
Messages
17
Re: Force 125 won't rev over 4000rpm

Thanks for the suggestions guys - much appreciated. The boat has a speedo, tach and a couple of other gages (fuel and batt charge) and I believe it came with the motor as original equipment. I think a decarbon may help, as 'Howeird' suggests. This will also be a new experience for me. I use the boat on Lake Conway in Orlando FL - I don't want to dump a load of crud into this beautiful water - nor do I want to splatter my driveway with sh*t either. Can this be done in an eco-friendly way, without going to a dealer?
 

howeird

Cadet
Joined
Oct 22, 2005
Messages
15
Re: Force 125 won't rev over 4000rpm

I have seen two methods to decarb your engine posted on this forum. One uses Sea Foam and a small gas tank and the other method uses Sea Foam Deep Creep. I used the Deep Creep method. There was a lot of smoke but no major ecological disaster. The resultswerewell worththe looks I got when I launched for the ten minutes of WOT
 

Matt Harper

Cadet
Joined
Feb 23, 2006
Messages
17
Re: Force 125 won't rev over 4000rpm

OK I'm sold on the de-carb idea. Checked on iboats marine store - no Sea Foam Deep Creep - no problem - quick drive down to West Marine - they never heard of it! Just offered me 'fogging oil'. "Will that de-carbon my Force two-stroke?" I ask - and get blank looks in return. So please - more help!! Where do I get this magic potion? I want revs and I want them bad!
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,753
Re: Force 125 won't rev over 4000rpm

You don't want to buy any flammable liquids online anyways, the shipping will be outrageously high.<br /><br />Got a farm supply store, Auto Zone, NAPA, CarQest, Checker Auto, etc near by?<br /><br />Some only carry the Seafoam liquid, not the aerosol Deep Creep.<br /><br />You can go to a dealer and get Mercury's Power Tune, or Yamaha's Ringfree.
 

eurolarva

Rear Admiral
Joined
Jun 24, 2003
Messages
4,182
Re: Force 125 won't rev over 4000rpm

If there is an advanced auto parts store in your area call them. They carry sea foam and seafoam deep creep in the West Palm Beach area.
 

Matt Harper

Cadet
Joined
Feb 23, 2006
Messages
17
Re: Force 125 won't rev over 4000rpm

Gents - thanks as always. I didn't think "autoparts" - just boat orientated. Thanks again.
 

Matt Harper

Cadet
Joined
Feb 23, 2006
Messages
17
Re: Force 125 won't rev over 4000rpm

Just wanted to say heartfelt thanks for all the advice re. my flat revving 125. Got the Deep Creep from my local Advance Auto Parts and went through the procedure, as advised on this forum. I warmed-up the motor on muffs and sprayed the Sea Foam into both carbs. It spat and farted a bit and then started running all lumpy, but did not actually stall. I shut it down, whipped out the plugs and sprayed into each cyl for good measure. <br />I left it overnight and flashed-it up again 24 hours later. My neighbors thought my house was on fire, but it blew out a lot of sooty dirt. Yesterday, I also did the 'steam clean' trick I read about, spraying a small amount of water into the carb throats while it was running.<br />I now have my 1000rpm back.<br />I'm very, very grateful for the helpful advice and encouragement.<br />In truth, I rarely run it flat-out - it's an old engine with God-knows how many hours on it, so I nurse it a little - but it's nice to know I've got 5 grand if I need it!
 
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