motor reving up at startup 87 force 125hp

[wildmaninal]

I got this boat first of this month, I finally got to take it out last weekend. The boat started to throttle up ok but then it bogged down and i noticed it was coughing at idle, so I loaded it back up brought it home. I found out the boat has been sitting for around a year, cant say the previous owner lied to me about the boat but he just didn't tell me the hole truth.

I took the carbs off cleaned them blew through each port with a football needle on a air gun then with just the air gun. Got the carbs back on synced them the best i could, replaced all the gas line from the tank to the carbs, replaced the bulb, put a can a sea foam in the gas. I checked the spark on the plugs and each plug fires fine, checked the diaphram in the fuel pump it looks good, done a compression check a couple of days ago it was 135 on all 4 cylinders. Went to start it after putting on the last gas line on and it revs after starting. I am trying to run it on muffs, just to verify the muffs should go over the vents just in front of the prop or am I wrong. I tackled a 79 evenrude 85hp wich had the same problem as this force it bogged down, well i got it fixed this force is a little different so any help would be appreciated. I adjusted the idle screws on the carbs 1 and 1/8 turn out on each carb, previous owner had them out several turns., Does not change the way the motor runs when I adjust them. Also the previous said he "governed" the throttle down because the boat was "to fast for him", could of just ran it at half throttle. He showed me the cable he supposidly messed with but honestly I dont think it made any change the butterflys still open all the way, or flat in the carb throat.

 

[foodfisher]

Re: motor reving up at startup 87 force 125hp

Filter through all that and ask a question. What's up?

 

[Jiggz]

Re: motor reving up at startup 87 force 125hp

Let's start as what the title says, high rpm at idle is caused either by misadjusted control cable or most likely a misadjusted idle screw which is located at the bottom of the control tower or timing tower. When you did your link and synch, with the ball link properly adjusted and idle screw backed off, the line on the cam should lined up with the slot line of the eccentric screw and the throttle valves fully closed. Of course, when you set the idle rpm through the idle screw, the line (cam and eccentric screw) will not line up anymore and the throttle valves opened slightly. What is you idle rpm now? It should be around 1100 at idle in neutral.

 

[wildmaninal]

Re: motor reving up at startup 87 force 125hp

I know i said idle screws on the carbs were adjusted way out buy the previous owner, well I meant mixture screws, I have not touched the idle screws. I did undo the cam and let the carbs close then reinstalled the bar between the carbs. I have no idea what rpm its running at because the rpm gage is stuck. I figure its running at half throttle. It idled fine before I took the carbs off but it had a caughing at idle. It was getting dark when I was messing with the boat last night, so I am going to get back out there today and see what I may have missed. Thanks guys might be posting back later.

 

[jerryjerry05]

Re: motor reving up at startup 87 force 125hp

Top post is a link from FrankA, called a linc and sinc.
Do that first.
Pics of the cable or what the PO messed with??
If it's the bar to adjust the timing you need to make sure before you ruin the motor?????

The air/fuel mix screws start at 1 turn out.
The factory says leabe them there.
I do on my twin 85/s

But you can smooth out the idle a bit but too far and you can do serious damage.

Bogging under acceleration?
Could be the fuel vent line is clogged.
The fuel pump diaphram is bad.
The fuel lines soft from ethanol(ethanol bad).
Or the timing off(pic of the adjustment).

 

[wildmaninal]

Re: motor reving up at startup 87 force 125hp

hey jerry I did read franks post at the top of the force forum. I think I got it straightened out. I did adjust the the throttle cable, the link between the cam and the throttle bar, or timing bar whatever its called, adjusted the iddle screw. Turned the mixture screw on both carbs one turn out. Now it idles smoth no coughing, and it throttles up smooth but I am still running it on muffs. I hate that the rpm gage is messed up I thought I had another one in a boat hull out back but I forgot I gave it away if I remember right. I cant get a pic at the time of the cable, but it is the lower cable under the cowling, the top cable is the shifting cable. I plan on taking it for a test run this afternoon I know i may have to do some minor adjustments once I get it in the water but its going to be interesting. I replaced all the fuel lines after I cleaned the carbs.

 

[wildmaninal]

Re: motor reving up at startup 87 force 125hp

Well I took the boat out, it is running much better but I didn't get full throttle out of it, I got it to about 40 mph, its a 16ft procraft bass boat 87 model should at least do 50 mph I would think if not better. I brought my cousin with me he did say the butterflys in the carbs is not opening all the way so I guess I need to adjust the throttle cable some more correct? It runs smooth otherwise. I also discovered a new problem the plate next to the fuel pump or to the right of the fuel pump is leaking obviously a bad gasket I dont know what this plate is for so I can get the correct gasket. Also with this gasket leaking would this have any affect on the compression check I got 135 on all 4 cylinders. I tried to upload a pic of the plate in question but I cant upload it saying file size to big

 

[TwoFish]

Re: motor reving up at startup 87 force 125hp

You will need to resize the images. They need to be around 150 kilobyte. I use a free program called Infranview. It allows you to resize and save for the web but most photo editing software will do this.

 

[jerryjerry05]

Re: motor reving up at startup 87 force 125hp

Comp sounds good.
40's not bad for any 125

You need to figure out the rpm's
Should be about 53-5500 at wot.
Could be the wrong prop?????
What prop's on there now?
Clean the connections at the motor and the tach.
On the back of the tach is a tiny black thing.
Looks like an arrow,in the center is a slot for a small screwdriver.
Try turning it.Remember the inital setting?

The butterflys don't need to go flat to be at WOT.

Take the cowl off.
Have someone go with you and push the throttle all the way.
See if the linkage is right.

Need to figure out if it's the tranfer port gasket or the fuel recirc system.
Is it about 3X4 inches or a long skinny one?

 

[wildmaninal]

Re: motor reving up at startup 87 force 125hp

My cousin did open the throttle all the way when we were out on the river I didn't gain much speed that when I hit 40 mph, before i was at 37 mph. I kept trying to downsize the photo of the plate, i got it down to 129 kb and it still wouldn't upload to this post so I uploaded the pic of the plate and the prop on photobucket. If you cant view the pics please let me know been a while sense I used photobucket. The number i got off the prop is 540 19 from what I could make of it, the numbers were really worn off. I believe the rpm gage has seen better days its stuck about half way up on the gage, so I asume its not fixable. Could i get a rpm gage from a I/O to work? I believe I got one in another boat out here, with any inboard/outdrive.

 

[jerryjerry05]

Re: motor reving up at startup 87 force 125hp

That's part of the fuel recirc system.
The gaskets are still available.
There are 2 different ones on each of the covers.
Try tightening them?

That's a stainless prop.
That 19 is actually like running a 21p alum.
Probably way to much for the motor.

Have a spare?
I'd start with a 17/19 p to start.

But you gotta get some kind of tach to figure out where you really are????
They sell a Tiny Tach it hooks right to the motor. Amazon sells them.
boat . net sells lots of parts contact them for a tach.

You sure that yours is hooked up right?
I try tapping on mine when it sticks.


No a I/O tach won't work.
You need a 20pole.

 

[emoney]

Re: motor reving up at startup 87 force 125hp

You probably should weigh the boat at some point, then weigh the trailer and subtract it from the 1st weigh-in. Most county dumps have scales or a local truck stop. Once you now the number, try to find the factory dry weight and see if your hull could be water-logged. 40mph doesn't seem like a "problem", outside of the prop change Jerry recommended, but a "water-heavy-boat" will sure slow it down. Have you had a chance to take a look under the carpet to see if there's rot showing? I've know guys that have removed 4-500 lbs of wet foam before. Just a thought.

 

[glenn property of pam]

Re: motor reving up at startup 87 force 125hp

if the tach is stuck half way up then its proberly not getting any voltage to it. check that it has 12v at the terminals with a volt meter. if it had a bad tach sender wire the tach would go to 0 rpm when powered up.

 

[wildmaninal]

Re: motor reving up at startup 87 force 125hp

I tapped I beat on the rpm gage and it didn't phase it I'm gonna call around Monday to the 3 boat repair shops we have and price the rpm gage. I started to undo the rpm gage a few days back I'm not 100% sure but I believe its never been messed with. I'm not affraid to work on anything really but I'm just a shade tree machanic. I do have another prop may even have 2 props but one on a older mercury and the other I have no idea what it came off of might of came off that 78 evenrude I use to have. I will see if its just a loose bolt on the plate. The props got be for a force or do I need to just see if the props match on the shaft? Thanks for all the help. There are 2 switches on the boat the main switch the the key switch for the motor u cut the main switch off it shouldn't have any power to the gages.

 

[wildmaninal]

Re: motor reving up at startup 87 force 125hp

I pulled up the carpet to check the deck before I made the deal on the boat. Deck is in good shape. What I was getting at on the last post is even with all the switches off the tach is still stuck, it would not hurt to check for voltage though I know.

 

[Jiggz]

Re: motor reving up at startup 87 force 125hp

If you verify there is voltage going to the gage, you can also go a step further by verifying there is a signal into the gage. You take AC volts from the gray (or purple) wire to ground and there should be some AC voltages fluctuating with the engine rpm. If there is ac voltages from the signal wire, then the gage is FUBR and needs replacement.

 

[glenn property of pam]

Re: motor reving up at startup 87 force 125hp

more modern tachs will zero when they are turned off. older ones will remain at last reading when you disconnect the power to them. your boat should be wired so the key switch supplies power to the gauges and not the master switch as theres no need for the gauges to be on when the engine is not running but not all boats are wired correctly. mine is showing 1k at the moment as i switched the engine off. if i turn the key on it will go to zero. so if the tach lost power while running it will have stayed at the last reading before it lost power

 

[wildmaninal]

Re: motor reving up at startup 87 force 125hp

Ok just thought I would update and got a couple of questions. I did end up buying a new tachometer I got it mounted and working, checked the signal to the old tach, it was getting signal. I got the gasket for the plate, the other gasket was bad. I looked for a prop found a 15 pitch aluminum prop I didn't buy it. I talked to a guy in another county and he said he could change the pitch on my stainless steel prop, he didn't have a used stainless in a 17pitch, so I decided to let him modify my 19 pitch prop it will save me about $70 a used stainless from him would be $200 but they completely rework them. So im waiting on the prop to get done.

I noticed I was idling way to high once I got the tach on there I was idling at over 2000 rpm or so, I got it idled down to around 1400 this is while running it on muffs this is as low as could get it. The came is just barely touching the roller on the carb and the roller is sitting right between the to lines on the carb, which the roller is all the way back, plate completely closed on the throttle. I dont know how the idle was changed because I could tell buy the way it sounded before I put the tach on the boat it was idling just fine alot lower before I put the gasket on the plate. Could that leak on the plate mentioned in an earlier post cause the motor to run different? Just curious.... will i be ok where im at on the adjustments and the rpm.

Last question I found out I dont have reverse, I believe its just another "adjustment" that the previous owner done. It acts like it trying to go in reverse, the prop shaft does turn when in reverse but you can stop it with your foot. Please tell me there is just an adjustment I am missing on this. Thought it was messed up my brother is having problems with going into reverse on his 75 evinrude 115 hp

 

[emoney]

Re: motor reving up at startup 87 force 125hp

You need to confirm if it's going into reverse or not by shifting it at the motor. It won't hurt to put it into to gear on the muffs to verify it's shifting while it's running, just don't leave it that way for a while. If it is, in fact, shifting into reverse there, then it's a cable adjustment and you'd be better served to post up pics of your particular set-up as they can be different.

 

[wildmaninal]

Re: motor reving up at startup 87 force 125hp

Here are a couple of pics I could not get a better shot of the shifting cable and where it hooks because its so far down in the cowling. I've got about 280 invested in this boat and I pretty much gave 2000 for it and Im sorta disapointed that Im having to do all this work , and he said he had the boat out and used it.... and I still got to do the water pump impeller, or I am going to replace it just to be on the safe side.