125hp force runs rough at low speed and dies at idle

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
Yes Sir will do. Thanks. And it should be at 30° at "wot" at cranking?

NO, you set it 28 at cranking-speed, because of the speed running at 5000 + rpms. it will fire at 30
To protect the life of the motor; you do not want it to exceed the timing/premature firing causing over-detonation!

It's called "static timing"
Make sure all spark-plug in the block
You will have to disconnect the neutral-switch OR Jump the starter-solenoid.
make sure your switch is set to ON & safety-lynard switch not activated (or you will not have spark)
 
Last edited:

B.B.Upch

Seaman
Joined
Apr 17, 2013
Messages
73
Ok I'm not getting a flash on my timing light? And yes I checked my timing light on my 71 torino and it's working. So must be in something I have wired on boat.
i pulled all 4 spark plugs. Ran wires into all 4 plug wires and grounded them to the block. Then ran a small jumper wire from 1 screw to the other on the kill switch for wot. I followed the video but still not getting anything. Am I missing something
 

Attachments

  • photo334278.jpg
    photo334278.jpg
    1.4 MB · Views: 2
  • photo334279.jpg
    photo334279.jpg
    1.4 MB · Views: 2

B.B.Upch

Seaman
Joined
Apr 17, 2013
Messages
73
Ok so I followed the video to a "T". Everything is set up. Carbs are closing completely amd opening good in "wot". The timing is set at 28° cranking in "wot". Good fuel in it and everything ready to go....
it will crank with the throttle at 1/4 forward in neutral position but when I try to bring it back to idle it acts like it backfires and spits then dies... it will not start In idle position... will not run in idle.. keeps spitting like its backfiring when I try to bring it back to idle???? Seems like I'm farther away now then what I was... at least then it was starting & running lol...
any help would be greatly appreciated. Thanks
 

B.B.Upch

Seaman
Joined
Apr 17, 2013
Messages
73
I didnt mention that it seems to start and run good as long as I have the throttle in neutral and a 1/4 or more forward.. but as soon as i bring it back to idle it starts to pop and die
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
Sound like you have the RPMS set to low, to adjust; loosen the nut on the bolt(located near the bottom of the tower-shaft) then screw-in with a flat-head screwdriver the bolt to increase the RPMS

You will need a Tach. on your boat or a "tiny tach" for testing. to set the RPMs in Neutral to 1100-1200 max. and about 750 RPMs in gear

You could do this by "ear" but then it becomes a guessing game
 
Last edited:

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
Ok I'm not getting a flash on my timing light? And yes I checked my timing light on my 71 torino and it's working. So must be in something I have wired on boat.
i pulled all 4 spark plugs. Ran wires into all 4 plug wires and grounded them to the block. Then ran a small jumper wire from 1 screw to the other on the kill switch for wot. I followed the video but still not getting anything. Am I missing something

Stop!! the plugs have to be in the boots & then grounded

"Then ran a small jumper wire from 1 screw to the other on the kill switch for wot"
DO YOU MEAN....neutral switch?
 

B.B.Upch

Seaman
Joined
Apr 17, 2013
Messages
73
Stop!! the plugs have to be in the boots & then grounded

"Then ran a small jumper wire from 1 screw to the other on the kill switch for wot"
DO YOU MEAN....neutral switch?

Yes sorry I'm meant the neutral switch. The small black box that has 2 screws on top and a button on bottom that tells the boat it's in neutral... and yes I was able to crank it over at "wot" and set my timing to 28.. the timing is correct.
I checked again for vaccum leaks with the starter fluid and it's all good. It did not pop like this before. So something is not right.. I did screw the idle screw all the way out so I could line up the cam plate with the 2 lines...
is this a lean sneeze that I am getting? Why is running good at wot but popping and dying going back to idle?
 

B.B.Upch

Seaman
Joined
Apr 17, 2013
Messages
73
Sound like you have the RPMS set to low, to adjust; loosen the nut on the bolt(located near the bottom of the tower-shaft) then screw-in with a flat-head screwdriver the bolt to increase the RPMS

You will need a Tach. on your boat or a "tiny tach" for testing. to set the RPMs in Neutral to 1100-1200 max. and about 750 RPMs in gear

You could do this by "ear" but then it becomes a guessing game

I was thinking this as well that I'm running the rpms to low... would this create the pop/backfire that I'm getting??
I will look into getting a small tach. Is there a post on how to wire it in?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,082
Where are the air screws set?
They start at 1 1/2 turn out.
They don't have anything to do with setting the idle up r down, that's the
towershaft and idle set screws job.
A small cough can be the screws , maybe the reeds, or the recirculation system?
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
I was thinking this as well that I'm running the rpms to low... would this create the pop/backfire that I'm getting??
I will look into getting a small tach. Is there a post on how to wire it in?

You will have to have the small cam-bushing(that opens the butterflies on the carbs) adjusted properly and / or increased slightly

AS Jerry mentioned make sure the fuel/air-mixture screws are set correctly; start with 1 1/2 turn out from LIGHTLY seated, then turn clock-wise if needed (rev. engine quickly between adjustment & wait for 5 sec. to correct it self)
DO NOT turn screws in more then one FULL turn out!!

these Tiny Tach. come with instructions (wrap wire around #1 plug-cable 4 to 5 times & secure then insulate so it does not pick up a signal from the other cables
 

B.B.Upch

Seaman
Joined
Apr 17, 2013
Messages
73
Yes air screws are 1 & 1/2 turns out from lightly seated.
I will post pictures below.
1 picture is of cam plate in idle position. The carb throttle screw is barely touching it...
1 picture is of the timing. This is where it is flashing. Dead on 28.
1 pic is of the idle screw. Lightly touching block when all else is set up.
The other cam plate picture is when it is in neutral at "wot"..

(Just a recap).....so to go back to when it was running (granted poorly) but still would start and run..... the cam plate was much further down. The idle screw was almost all the way in and the timing was set around 32 at "wot". This is what I saw when I first checked the timing.. then I backed it down to 28....
 

Attachments

  • 15944054469818368810461048745830.jpg
    15944054469818368810461048745830.jpg
    1.3 MB · Views: 3
  • 15944054957167292609000455353553.jpg
    15944054957167292609000455353553.jpg
    1.5 MB · Views: 3
  • 15944055449412303171334262180488.jpg
    15944055449412303171334262180488.jpg
    1.4 MB · Views: 3
  • 15944056784434068298516801169040.jpg
    15944056784434068298516801169040.jpg
    1.4 MB · Views: 3

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
Going over pictures from left to right

#1 pic. is this at the initial set-up?
#2 pic. looks good
#3 pic. this gets the final adjustment in the water to set-up the idle-rpms in neutral & in gear
#4 this would be the position of the cam-plate when the engine it in neutral/idle after set-up but NOT at Wide open throttle

Order of events to set-up

#1 set static-timing
#2 link & sync. Carburetors by setting-up all carbs. opening/closing equally. set cam & bushing bushing
#3 verify when in WOT all butterflies are open equally
#4 start motor in neutral in water adjust bolt on timing tower (at the bottom) to 1100 or so if achieved... put in gear verify it runs around 750-800 rpms

sometimes you may have to tweak (very very slightly) the lump sided bushing slightly to achieve a smooth idle
 
Last edited:

B.B.Upch

Seaman
Joined
Apr 17, 2013
Messages
73
Going over pictures from left to right

#1 pic. is this at the initial set-up?
#2 pic. looks good
#3 pic. this gets the final adjustment in the water to set-up the idle-rpms in neutral & in gear
#4 this would be the position of the cam-plate when the engine it in neutral/idle after set-up but NOT at Wide open throttle

Order of events to set-up

#1 set static-timing
#2 link & sync. Carburetors by setting-up all carbs. opening/closing equally. set cam & bushing bushing
#3 verify when in WOT all butterflies are open equally
#4 start motor in neutral in water adjust bolt on timing tower (at the bottom) to 1100 or so if achieved... put in gear verify it runs around 750-800 rpms

sometimes you may have to tweak (very very slightly) the lump sided bushing slightly to achieve a smooth idle

Thanks. That is the order I set it up except i did it with a water hose at the house and not in the water at the lake.... and before I get into answering this I want to add that in that set up i kept getting a backfire/pop out of the carbs. So this morning I went out and advanced the timing and now it no longer backfires/pops out of the carb... instead I'm getting a pop out of the exhaust? Mixture is what I'm guessing...

So pic 1 of the cam plate is how I set it up in neutral/idle (throttle straight up and down) by adjusting the throttle cable and the double sided screw. The 2nd pic of the cam plate is when the throttle is in neutral/wot (where the throttle is in neutral but forward for starting)... not actually "wot" lol.... sorry I dont know what that's called.

The picture of the flywheel is where I had the timing set up.. but as I mentioned it was backfiring out of the carbs so I advanced it until that stopped. I have not retested to see where it is at now.

I know this has been a lot and I have searched a lot of other threads on here.. I just want to say thank you all for the helpful advice... the videos... and most importantly your patience lol.. this is a great forum and you are greatly appreciated.
 

Redbarron%%

Chief Petty Officer
Joined
Dec 7, 2017
Messages
479
A couple of questions.
1 - is the idle at 9 Degrees ?
2.- is there clearance at idle between the cam and roller at idle?
3. - If there is a timing problem and the idle is not at 9 degrees at idle and 30 degrees at WOT then the bias circuit maght be bad. low timing tends to reduce the torque at idle. Most of the increase in rpm at the lower end is due to timing advance then throttle opening. If the registration between the timing and the cam operated carbs is important.
I don't know if this applies to your situation but I fought timing and carb issues for a long time and I think a lot of it was due to a bad bias circuit in my CDI box and then the lack of a bias circuit when I installed CDM modules. I had a difficult time getting the 9 and 30 degrees at the same time along with WOT of the carbs.
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
I'm not good at explaining things, here are the instructions; follow them carefully & don't skip a step!
 

Attachments

  • IMG_2036.JPG
    IMG_2036.JPG
    84.3 KB · Views: 6
  • IMG_2037.JPG
    IMG_2037.JPG
    83.6 KB · Views: 6
  • IMG_2039.JPG
    IMG_2039.JPG
    61 KB · Views: 5
  • IMG_2038.JPG
    IMG_2038.JPG
    80.2 KB · Views: 4
  • IMG_2040.JPG
    IMG_2040.JPG
    93.4 KB · Views: 4
  • IMG_2041.JPG
    IMG_2041.JPG
    82.2 KB · Views: 4
  • IMG_2044.JPG
    IMG_2044.JPG
    91.3 KB · Views: 4
  • IMG_2043.JPG
    IMG_2043.JPG
    102 KB · Views: 4
  • IMG_2046.JPG
    IMG_2046.JPG
    84.5 KB · Views: 4
  • IMG_2042.JPG
    IMG_2042.JPG
    93.9 KB · Views: 4
  • IMG_2045.JPG
    IMG_2045.JPG
    96.6 KB · Views: 6

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,350
I don't know if we asked already?
Have you checked the key in the flywheel if its not broken & the Flywheel is off (as in not in the right spot?
Is the Magnet inside the flywheel ok ?
 

B.B.Upch

Seaman
Joined
Apr 17, 2013
Messages
73
I don't know if we asked already?
Have you checked the key in the flywheel if its not broken & the Flywheel is off (as in not in the right spot?
Is the Magnet inside the flywheel ok ?

Yes Sir it is all as should be.. and to your pictures u explained it well and follows same line as Frank's video... I just dont know why when I set it up that way that it was out of timing... and how I can get it running in idle... it talks about adjust it while in idle but I cant get it to run in idle lol
 

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,593
Some comments to your pics in #32.
Pic 1 This is the throttle pick up point. Throttle rod disconnected to the timing tower. You set the pick up point with the roller that has an exentric hole.
Pic 2 This is the static timing 28 dgr BTDC at WOT.
Pic 3 You set the throttle butterflies with the rod to horisontal at WOT.
Pic 4 The cam position would be in this area with the rod connected to timing tower at idle.
Maybe it would be a little more up at the cam to have the idle adjusted to 1100-1200RPM at muffs or 700-800RPM in gear in water.
Normally the roller is a bit above the marks at idle. The marks is only for throttle pick up point adjustment.
 
Top