125 HP cranks fine without plugs

[jerryjerry05]

Gear oil: 32+ oz. I fill till it comes out the vent and then fill the vent till it comes out the fill.
​uses a bit more but that way I'm sure it's full.
Trim @ Tilt fill when all the way down. Add oil 30wt. then cycle it up and down. Then add more while down.
NEVER add oil when it's in the up position. You can push oil up into the electric motor.

​Running at idle, skip : the air screws need adjusting. Turn in till lightly seated(remember the turns) then out 1 and 1/2 turn.
​That's the base setting for initial adjustment.

​Look up starting procedures. I/E fast idle, choke.

​Stiff throttle: unhook the connector at the motor. Have someone spin the prop as you shift. try shifting as they spin the prop, is it still stiff?
Might be a bad cable? or linkage needs reset.
​The throttle advance arm is held on with a 7/16 nut. Loosen it just a tiny bit. It's supposed to be tight but not so tight as to stop the throttle.

 

[Jiggz]

You have done much of the work and learned along the way. Absolutely not recommending taking it to a shop but instead keep posting here to tune it up. It is not that hard and basically it is done one step at a time. As Jerry mentioned, start with the "air screw" (fuel air mixture screw) setting. And then follow it up with setting of the idle. As soon as you get it to idle you can check the timing. But you just need to do the static timing which should be posted on top of the flywheel or go with the generalized setting of 28 BTDC.

 

[pantaloonz]

Jerry and Jiggz,

thanks for the votes of confidence, I will take your advice and keep at it. I think I can do the air screws, that sounds pretty straight forward, once I get it started and idled again

About the tilt... yeah... It's a NEW two wire tilt in a three wire boat.... (I found the correct wiring harness to convert it, that'll be next week) -- rookie move there.

Stiff throttle: I hope I explained correctly, it takes considerable pressure to move the throttle forward enough so that I can feel the engine revving up.

This unit has a pull out neutral, where the whole lever pulls out so as to give throttle out of gear. The first forward inch of moving does nothing.. then it gets very hard to move, if I push hard I'll start to hear the engine starting to revv up. Almost like there is "play" in it.. now I think I understand this is the area of play that the throttle lever moves when switching into and out of gear, so there should be no throttling up in this space? (I hope that makes sense) but:

Forward;
Pulling the button and shifting into forward; this is actually smooth, I can hear the gear connecting and the prop moves freely and smoothly.. but it does take considerable force to move past idle speed, and the engine would "cough" a little during acceleration, but then level out (maybe this is the air adjustment)
-- I assume this is the adjustment on the throttle advance arm that needs adjustment?

Reverse:
Pull the button and going into reverse is also smooth. I hear that same gear engage sound and the prop motion is smooth. The motion to accelerate the boat in reverse is easier though... (I know that sounds weird) but it is.. reverse gear behaves just the way I expect it to.

Hopefully as I work the engine back to life starting will become more straight forward.

Question 1 is there supposed to be foam inside the black carb carburetors covers? to filter air?..

Question 2: while the engine was running water streamed out of the trim tab? under the cavitation plate, and smoke came out of the two holes in the upper unit....
Sorry for the newb question but that seems like two very small holes for exhaust.. how do I know water is actually cooling this engine properly??

Not sure when I'm going to do the next round of work on this, but I'll keep you guys informed.

-Pantz

 

[pantaloonz]

Quick carb info:

Ok I went out today and put the muffs on, and much to my pleasure It started on 2nd key turn.

I had the cowling off and I noticed then when I choked it, I got some fuel spilling from the carb (not the bowl) right out where the butterflies are. Not a whole lot maybe a tablespoon? .. The engine was not complete down though so the carbs are tilting in towards the front of the boat.. should the engine be completely vertical when doing testing?

Anyway on the air mix screws.. the pictures I saw show the screw inside the carbs.. but I don't see it on this model.. I looked in both carbs and did not see a turnable screw inside there. The only screw I see that's adjustable is a screw with a spring on it that screws into the top of the bowl.. since both carbs have it I think this is the screw being discussed. ... I bottomed the screws out (lightly) I was a bit confused to see they did not bottom out at the same slot orientation. I say this because they were both set with a vertical slot, the top was two turns out, the bottom was 2 and 1/4 turns out.

Anyway I bottomed them both out, then pulled back 2 and 1/2 turns. It seemed to idle fine. When I manipulated the throttle lever by hand, the engine had a hard time staying started. When I used the stick (still pretty hard to push down) the engine did much better... I took it up to 4,000-4500 RPM and had some pleasure to see water coming out the two power flow holes. ..

It's still a bit choppy.. but now it idles on first start, and seems to be throttling well from (albeit a bit hard ) from the stick. Before I adjust throttle linkage or throttle advance I'd like to make sure I have the mixture right.. The idle seems a nice tempo.

Here's a picture of the screw I'm manipulating, I'm standing directly over the engine.



What do you guys think.. those are decent looking for 31 yrs old

-Pantz

 

[jerryjerry05]

That's the screw to adjust the air/fuel mix at idle.
Read the posts at the top of this forum to learn how to adjust the screws.
​They do nothing past idle.

​The difference in the slot orientation is how the screw was made.
It means nothing where the slot starts or ends up.
The amount of turns is what counts.

2 and 1/2 might be too much??


​To set the air screw: gently in till it just bottoms out.
Then out 1 1/2 turn out.
There is an equalizer hose between the carbs.
​You need to pinch this off.
Then motor running in the water.
Preferably in gear.
​Turn the top air screw in 1/8th a turn until the motor kicks, buck, stalls.
Then out 1/2 turn.
​You need to wait 10 seconds between the turns to burn the fuel at the old setting.
Repeat on the bottom carb.
Then do it again on both carbs.

But before you do any adjustments. Clean the carbs and make sure the floats are set right.

 

[pantaloonz]

Hi and Thanks Jerry!

I printed off the diagrams and looked closer and was indeed reading them wrong, so yeah that's mix screw and yes I read the number of turns wrong too, I'll need to set those to 1 and 1/2 turns as you said.

On a fast rev, the engine is coughing and does die if I throttle up too fast.-- is that more likely a lean or rich problem?

In regards to cleaning the carbs, and checking the floats... don't I need to remove the carbs to do that properly?
I don't have replacement gaskets and such.. won't I need those due to hold old this engine is?

The throttle :

I have watched the timing and carb tutorial three times now, and watched a few more videos on that process. My throttle is definitely too hard to move now that I've watched these videos.

-Pantz

 

[SkiDad]

I would set them to 1 turn out - my 1985 ran real good there. When you do it you need to adjust your idle some b/c turning in that much as you have to will make the idle go up quite a bit. Once you have your mixture set to 1 turn take it to the lake and warm it up - put it just into gear and have someone steer - set the forward idle speed in gear to 750 rpm. then tighten the idle lock screw again. remember this idles screw is way at the bottom of the tower (not the one at the top)

I have all the gaskets for your carbs (was going to do mine before I sold the boat) - PM if you want me to send them to you free of charge.

 

[jerryjerry05]

SkiDad "Yours" runs good at 1 turn out.
​His could be way different than yours.

Example:The factory said to set all 86-91 3 cyl. motors at 1 turn out.
Mine worked best at 1 and 1/8th.
One customer needed 2 1/8th turn out.
Depending on the carb and the machining it could be set anywhere??

 

[pantaloonz]

hi all

been working on the internior and trim so I'm just getting back to the engine issue.

The throttle as I said is very hard to move, I'm not able to push the throttle cam by hand when it's all connected.

When I pop off the arm, I'm able to move the cam through the throttle, from start to WOT easily. I noticed that there are two score marks on the cam, the current setting was close the top mark though that top mark was not perpendicular. Those are minute adjustments I can make on the arm but something is too stiff..

I cannot move the throttle arm by hand either red lines (it won't budge) even with the arm disconnected from the cam. Maybe I'm being wimpy and it's not supposed to move easy? The throttle lever at the helm is not attached to the hull, I don't want to put it back until I get this part fixed.

Getting Very close now!

So the red arrow show the the thing that I cannot move by hand.

But there are two lines, in my last picutre there is a red question mark,.. what does that one do? (shift?)




Thanks!
-Pantz

 

[pantaloonz]

ok

this will be hard to explain, but there are two parts making contact that's preventing th motion. on the lower part of the tower rod. there is an armature that's hitting another white piece only after a few millimeters of movement..

It's been hitting that white part for a while because there is paint missing.. I'm definitely not sure what to go after at this point.

All I know if that I have a tiny tiny bit of motion, but it's certainly not going to get anywhere past idle as it stands right now.

Hope these pictures help the description

 

[pantaloonz]

ok I feel pretty dumb...

The cabling has sat for 5yrs.. it was just stiff.. I used PB blaster and starting working the controls.. they are moving. Now I understand that stopper thingee in my last post. When the engine goes in forward, or reverse that lever will be above or below that white component allowing lots of throttle. Otherwise the level sticks right there and only allows a little bit of throttle..

I need to do a lot more reading before fine tuning these cables. there are adjustments at the remote contol, adjustments at the cables, and more adjustments at the engine!! :O

I did go ahead and reset the throttle cam the score lines were not perpendicular, that is now fixed with a minor adjustment on the throttle arm (I think that's what it's called)

I just need to mount the remote control and this boat is ready for a water test!!

-Pantz

 

[gm280]

ok I feel pretty dumb...

The cabling has sat for 5yrs.. it was just stiff.. I used PB blaster and starting working the controls.. they are moving. Now I understand that stopper thingee in my last post. When the engine goes in forward, or reverse that lever will be above or below that white component allowing lots of throttle. Otherwise the level sticks right there and only allows a little bit of throttle..

I need to do a lot more reading before fine tuning these cables. there are adjustments at the remote contol, adjustments at the cables, and more adjustments at the engine!! :O

I did go ahead and reset the throttle cam the score lines were not perpendicular, that is now fixed with a minor adjustment on the throttle arm (I think that's what it's called)

I just need to mount the remote control and this boat is ready for a water test!!

-Pantz

Understand how things work make things easier to fix and repair when they don't work next time. So every little bit of new info is a good thing. JMHO

 

[pantaloonz]

Hi All

I'd like to consider this thread complete since the original topic was about the plugs/compression/starting

This was resolved by the new starter, new plugs and dropping the lower unit and putting it back in.

I'm going to start a fresh thread on the throttle stiffness.

Thank you everyone.

Key learnings:
Compression testing really is a key move.
Learning how and when to replace old oil and lubricants is very beneficial
Clean clean terminals is a must.
Try not to exchange parts (2wire-3wire) as long as its doesn't break the bank

-Pantz