evinrude ski twin timing question

[gwoloshyn]

Hello, I'm following my service manual for link and sync on a 1966 ski twin and I'm confused by the last instruction. It says: "manually rotate armature base to full spark position". I know what the armature base is but what exactly is full spark position in relation to this? I'm supposed to do this and then set my throttle control linkage collar to this. Any help appreciated..

 

[samo_ott]

Re: evinrude ski twin timing question

Huh. Odd, usually what you do it adjust the cam under the ignition plate so that the carb just starts to open when the roller is between the two marks on the ignition plate.

 

[F_R]

Re: evinrude ski twin timing question

Hello, I'm following my service manual for link and sync on a 1966 ski twin and I'm confused by the last instruction. It says: "manually rotate armature base to full spark position". I know what the armature base is but what exactly is full spark position in relation to this? I'm supposed to do this and then set my throttle control linkage collar to this. Any help appreciated..

As you advance the throttle, the armature plate under the flywheel rotates. When it rotates as far as it will go (IN GEAR), that is full spark advance. At that point, the arm on the vertical throttle shaft should just begin to move the rod that kicks the carburetor throttle wide open.

 

[samo_ott]

Re: evinrude ski twin timing question

I thought that if the throttle was advanced all the way while in gear then it was at full throttle and the carb butterfly should be wide open and horizontal?

 

[F_R]

Re: evinrude ski twin timing question

The key words there are ALL THE WAY. As you advance the throttle, the armature plate rotates. As it does, it picks up the carb linkage via the roller on the brass cam. But the carb opens very little...yet. When the armature plate reaches full advance, THEN the situation I mentioned above takes place, and the carb is kicked wide open as you CONTINUE to move the throttle. When the spark is at full advance, and the carb open just a bit, that is the CRUISE throttle position. Saves gas, on the right boat. The boat has to maintain plane when in cruise throttle position for it to be effective.

This is one of the most common mal-adjusted, messed-up parts on the motor.

BTW, speaking of mal-adjustment, the carb butterfly should start to open when the mark on the brass cam aligns with the POINTER on the intake manifold.....not the roller.

 

[gwoloshyn]

Re: evinrude ski twin timing question

Thanks for the help. I currently have two issues with this. First, I rotated the armature base by hand to full spark, and adjusted my collar accordingly. Problem is, when I advance the throttle using the small control lever on the outside of the motor, the armature will not reach the stop. It falls short about a half an inch. Then, when the throttle lever continues to open up the carb butterfly, it opens it wide open, then when I move it back it just snaps back to closed.

Also, is the armature base supposed to move quite freely or is it supposed to be sluggish and must be moved back in position by hand? I think it may need some grease.

 

[F_R]

Re: evinrude ski twin timing question

You probably suggested the cure. You may have to remove it and clean the old grease off and re-lube it. I consider that to be a normal part of magneto service and routinely do it. If you do, grease it sparingly. Too much grease will just splatter off and foul the points.

The spark plug wires might be too short or incorrectly routed and pulling on the plate too. Or there may be a problem with the #35 over-center spring assembly on the vertical shaft. Is the #68 bushing in place?

 

[gwoloshyn]

Re: evinrude ski twin timing question

I think I helped the plate issue. I removed it and re-greased underneath.

The only problem I have now is that when I actuate the throttle past full advance, to open up the butterfly, it will not open fully horizontal and will get "stuck" in that position unitl I throttle down and at that point it the spring just snaps it back to close.

I've found that fixing this issue involves moving up the collar on the throttle rod, but that would not be correct with the 1/32" gap at full advance specification.

 

[gwoloshyn]

Re: evinrude ski twin timing question

Well I've had enough. I spent all damn day trying to time this motor, got it all back together, and nothing is different. Still runs like ****. It's spitting back at idle speeds and I have no idea what the problem is.

The only thing I didn't do was rebuild the fuel pump but it looks fine.. Where can I get a kit for this motor? Iboats does not carry it. 1966 evinrude ski twin 33653

 

[HighTrim]

Re: evinrude ski twin timing question

Is that the original problem, the spitting back?

Have you first tried adjusting the needle? Have you inspected the reeds?

 

[gwoloshyn]

Re: evinrude ski twin timing question

Yes this is the original problem. I started a thread on it here: http://forums.iboats.com/showthread.php?t=499623&highlight=ski+twin+sputtering

Ive tried adjusting the needle, which way should I go? I have not inspected the reeds but I will do that next.

 

[HighTrim]

Re: evinrude ski twin timing question

I start mine by turning them in until gently seated, then back out 1.5 turns. Turn in slowly 1/8 turn at a time, giving it time to respond, until is starts backfiring, then turn it back out 1/4 turn. Within that 1/4 turn will be the best idle position.

If the reed plate is damaged, it will spit back through the carb as well.

 

[gwoloshyn]

Re: evinrude ski twin timing question

It's not spitting back out the carb, I put my hand over the intake but only felt suction. Something is going on.. No idea what it is. And worst, the repair shops around here will not service this old of a motor. :facepalm:

 

[gwoloshyn]

Re: evinrude ski twin timing question

Guys, the fuel pump MAY be the problem. It's spitting and will not stay running at idle, but it runs OK when it revs up. So, my theory is that when it's running at higher RPMS the carb is kind of sucking fuel in, where as at idle speeds the pump helps deliver gas. Also, right after it stalled out I removed the fuel line from the carb nipple and there was no gas immediately present, but there was some about an inch down from the opening.

Where can I get a fuel pump kit for this motor?

 

[F_R]

Re: evinrude ski twin timing question

Can you keep it running at idle by squeezing the bulb? That does what the fuel pump does, which is keep the carburetor full.

Don't condemn the fuel pump without eliminating other possible problems. Even a small air leak anywhere between the fuel pump and level of gas in the tank will admit air. That air kills the fuel pump action. An often overlooked area is the little pins where the connector plugs onto the tank. If it slops gas out there, it also admits air.

EDIT: I am fairly sure, but not absolutely, positively sure, that fuel pump kit 18-7820 here at iboats should work. One of the gaskets may be incorrect or something.

 

[gwoloshyn]

Re: evinrude ski twin timing question

All of my connections look fairly good. There is a small amount of play in the fuel tank connector but no gas is coming out. I'm going to fit the fuel pump on my other parts motor and see what I get.

EDIT: I removed my low speed needle and it turns out I never replaced the packing washers. They were in pretty bad shape. Chance that there could have been a leak through here?

 

[F_R]

Re: evinrude ski twin timing question

Possibly. That would admit air to the idle circuit.

 

[gwoloshyn]

Re: evinrude ski twin timing question

That didn't help at all. I'm out of options guys, looks like I gotta fork out money for a mechanic, if I can find one.

 

[F_R]

Re: evinrude ski twin timing question

I guess you don't want to haul it down to FL, huh?

 

[gwoloshyn]

Re: evinrude ski twin timing question

Not especially haha. Thanks for the offer though.. and the help.

I was looking on youtube for a similar problem and I found this 225 evinrude doing an "idle pop". This is what my motor is doing, only much worse. It will not run without the choke on, and if the chokes on it still pops frequently.


skip to 2:45
http://www.youtube.com/watch?v=nUWbq1GcKlQ