Force 125 will not go above 3800k rpm can you help?

[tteal]

If I go to approx 3/4 throttle, the boat runs great at approx 3800k rpm and is running at approx 27/28mph according to my GPS. If I try to give it more throttle it sort of bogs down and doesn't gain any speed and still seems like it's getting flooded or something weird. Any help troubleshooting would be great. Here are some things that I know of the boat:<br /><br />- Idle is set @ 800/900rpm<br />- Slight vibration @ idle <br />- 13x19 prop (has a nice ding/bend on one of the blades)<br />- 19 foot Bayliner Capri (weight is approx 1775lbs)<br />- Primer bulb is nice and hard when underway.<br /><br />What can I do now? What should I look for? Any help would be great and I'm sure glad I have a tach now.<br /><br />Thanks,<br /> Tim

 

[JB]

Re: Force 125 will not go above 3800k rpm can you help?

Hey, Tim.<br /><br />Can you please help US??<br /><br />Forget the irrelevant part of the history. Tell us what engine you have and what your trouble is.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=17;t=009035

 

[tteal]

Re: Force 125 will not go above 3800k rpm can you help?

JB,<br /> Edited post to hopefully get to the meat of the problem. Thanks.

 

[roscoe]

Re: Force 125 will not go above 3800k rpm can you help?

I guess I would start by checking for spark and compression on each cylinder.

 

[tteal]

Re: Force 125 will not go above 3800k rpm can you help?

roscoe, <br /> As always, I appreciate your help. Compression was checked a few months ago and 125psi + in all four cylinders and within 10 or so % of each other.<br /><br /> I guess I can check the actual throttle linkage and see if the carbs are opening all the way when I use the linkage and see if the 2 carbs are opening all the way? Sound like a good start? <br /><br /> It just seems weird to me like a hesitation problem and it's only when I try to go more then 3/4 throttle. I'll do a more exhaustive search and see if I can come up with something.<br /><br /> Any other suggestions?

 

[tteal]

Re: Force 125 will not go above 3800k rpm can you help?

Ok a little more information here since I took the boat out again today. <br /><br />Pulled plugs --- they all look great.<br /><br />Look at the throttle linkage - one thing I did notice is that the bottom carb the butterfly (the part that opens up when you give it throttle) was opening more then the top one.<br /><br />Hope that might help someone help me out here.<br /><br />Thank you,<br /> Tim

 

[tteal]

Re: Force 125 will not go above 3800k rpm can you help?

Hello (hearing echo). Anyone able to help me?<br /><br />Thanks,<br /> Tim

 

[roscoe]

Re: Force 125 will not go above 3800k rpm can you help?

Hi again.<br />All I can think of is a carburator problem, or a sync problem. I know nothing about doing a link and sync. But the manuals cover it. Seems it is different for every model.<br /><br />I'm going to try to get some help in this forum.<br />Please hold.................

 

[lakeman1999]

Re: Force 125 will not go above 3800k rpm can you help?

I had a problem, the engine flooded out at wot, and would run at a lesser setting (float appeared to be clear, and worked ok). Found a peice of plastic in the fuel hose, that appeared to be a long thin wormlike chip that evidently was left in the tank when the holes in where the fuel guage mechenism was screwed to the tank. From all that I could figure, evidently worked it's way through the pickup, and up the fuel line, till it ended up just below the carborator bowl (needle valve). Evidently, when there was a heavy fuel flow (wot) it would be pulled up to keep the needle valve from closing, but at slow speed, and a lower fuel flow would drop back down, allowing the needle to seat, then when wot, and increased fuel flow it would again come up to block the needle from closing. Evidently the end as the tap began its cut made the long thin chip's end minute enough to just stick up and block the needle from closing, but then the center part of the chip was too small to work on up into the carb bowl.

 

[lakeman1999]

Re: Force 125 will not go above 3800k rpm can you help?

PS, this was on a 94 force 70, on a pontoon with a 28 gallon fuel tank. And it happened at a very embarassing moment, when I had a senator and his (young) wife aboard, judging an annual 4th of July boat parade decoration contes on our lake.

 

[JB]

Re: Force 125 will not go above 3800k rpm can you help?

Howdy, Tteal.<br /><br />Did this package ever perform differently? What year is your engine?<br /><br />If this is a drop in performance, my guess is that you have: <br />*One carb with a clogged high speed circuit, <br />*Do not have the carbs synched or <br />*Do not advance the ignition when advancing the throttle.<br /><br />I would start with an overhaul and thorough cleaning of all carbs, then a careful Link 'n' Synch by the book.<br /><br />Good luck.

 

[tteal]

Re: Force 125 will not go above 3800k rpm can you help?

Thanks for the suggestions.<br /><br />JB,<br /> I'm not sure if the outboard ever performed differently to be honest. The O/B is an 85 Force 125.<br /><br />I'll look closely at the fuel setup and see if I can't come up with anything.<br /><br />Thanks again everyone.

 

[jim dozier]

Re: Force 125 will not go above 3800k rpm can you help?

Check the throttle butterfly operation again. Both butterflies should be the same. Watch them as you move the control and see if one of them is going past full throttle (parallel to air flow) and starting to close again in the opposite direction (over-rotating).

 

[clanton]

Re: Force 125 will not go above 3800k rpm can you help?

If you have good spark on all cylinders, remove the carbs clean, reinstall carbs, do a link/sync. You have to insure the float and needle/seat is working. Do not mix carb parts. Check for coil arcing to block.

 

[tteal]

Re: Force 125 will not go above 3800k rpm can you help?

jimd,<br /> You've described exactly what I've noticed (one of the valves on the carbs is opening more then half-way) and over-rotating. <br /><br /> How can I correct this? Just the linkage adjustment or ?<br /><br />Thank you!

 

[The Marine Doctor]

Re: Force 125 will not go above 3800k rpm can you help?

Disconnect the throttle actuator.<br /><br />Then pull the acctuator back from the throttle cam.<br /><br />Loosen the small screws that are on the throttle sync.<br /><br />Let the cam and the other carb fall loose.<br /><br />Once they are loose and seem to both close, tighted the screws.<br /><br />Next. Hook up the actuator and advance to full throttle (Engine is NOT running).<br /><br />Check to see if both plates are level.<br /><br />If they are the same but not level...adjust the actuator rod.<br /><br />TMD

 

[tteal]

Re: Force 125 will not go above 3800k rpm can you help?

Marine Doctor,<br /> I lost your previous email to me. If you get a free moment, I'm interested in a few items as previously discussed. Could you please send me another email please at: tteal@tealnet.com<br /><br />P.S. Thanks for the advice!!!!!!

 

[The Marine Doctor]

Re: Force 125 will not go above 3800k rpm can you help?

You should have Email.<br /><br />TMD

 

[tteal]

Re: Force 125 will not go above 3800k rpm can you help?

TMD,<br /> You have a return email. Thanks!!!!<br /><br />Edited: just got your email.

 

[The Marine Doctor]

Re: Force 125 will not go above 3800k rpm can you help?

I will have a look at it tomorrow morning at work.<br /><br />TMD