1956 15 hp throttle cam

[bigroystoys]

i have a 1956 evenrude 15 hp, it runs fairley well on a 14 ft aluminum boat but wont plane out, i have replaced coils points carb & plugs, old points were set at .4 ran like a dog, set new points at .20, runs better but still kinda plowes, i was watching the throttle roller move along the cam and in the idle position it sits on a plug wire, as i twist the handle it rolls into a dip then hits the cam, at full throttle i think the butterflys are only opening about 3/4, it just doesnt look right, i cant find an affordable 25 hp in the kc area, any ideas for a new member, thanks.

 

[Philip_G]

Re: 1956 15 hp throttle cam

I'm sure others will stop in with far more to offer, but this thread might be a good starting place. I was just reading it the other night myself.

http://forums.iboats.com/showthread.php?t=334083

 

[bktheking]

Re: 1956 15 hp throttle cam

What do you mean "sits on a plug wire"?

 

[bigroystoys]

Re: 1956 15 hp throttle cam

thanks for responding, with the tiller handel twisted down in the idle position the throttle roller sits on a plug wire and as you twist the handle it rolls off and on to the cam, doesnt look right to me, i could send a pic if you could tell me how to down load one on here

 

[Fisherball]

Re: 1956 15 hp throttle cam

Buy a manual for your motor!!!! It'll pay for itself 100 X over & the motor will run as good (& last as long) as possible. Mine cost me $30.00 & has saved me $1,300.00.

 

[bktheking]

Re: 1956 15 hp throttle cam

Post it to imageshack.us and copy the link to the forum.

 

[bigroystoys]

Re: 1956 15 hp throttle cam




hope this pic works i can try again

 

[kbait]

Re: 1956 15 hp throttle cam

If the motor runs in that position, something's definitely awry. As you advance the throttle (armature plate) the cam follower wheel should ride only on the cam, and not begin opening carb butterfly until it's between the 2 lines on arm. plate. You're motor shouldn't have the spark advanced near enough to run if you try to start it in that position, I wouldn't think..
Check compression, and spark with a tester (1/4" bright blue spark needed) to see where you're at, and post back.

 

[bktheking]

Re: 1956 15 hp throttle cam

hope this pic works i can try again

Just a guess here, i'm thinking the throttle gear teeth are out of sync, start position should be in the middle of the cam, idle at the lower side and WOT near the top of the cam (largest point). Or something is bent pretty bad causing it to be out.

Put the tiller handle to idle and take a picture of the gear where the tiller handle meets the gear that goes to the bar that controls the magneto, do the same @ WOT.

 

[bigroystoys]

Re: 1956 15 hp throttle cam


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top pic is wot, second pic is at a stop, thanks

 

[bktheking]

Re: 1956 15 hp throttle cam

Looks good, could it be that the PO put the magneto plate back on in the wrong position, have you ever had it apart?

 

[bigroystoys]

Re: 1956 15 hp throttle cam

when i changed points i could tell it had been apart before, should i try moving the mag plate, if so do i have to remove points and coils

 

[bktheking]

Re: 1956 15 hp throttle cam

No, there are 4 screws that hold the plate on, 2 through the coils (1 through each coil) and 2 through the plate. I'm not saying i'm right here, I'm saying judging by how far out you are and that it runs like a dog and that the roller rubs on the wires and the throttle will only go 3/4 that something with the setup is out of whack, we figured that the gears look good, only thing left is the plate, it sure would be difficult to set it up that way the the arm that attaches to the plate would be out too. You would think though if it was out that far it wouldn't start. I'd have to see it to be sure.


ADDED- Ya ignore that, the screws on the magneto are staggered in such a way that you can only put put the magneto on backward which it's not. Anything on the link and stop assembly bent??? The throttle not going all the way is the issue, are the wires routed behind the bar going to the link, are the wires too short?

 

[restornator]

Re: 1956 15 hp throttle cam

At WOT the throttle governor should come in contact with the shift arm. There are 3 settings that step up as you go from N-R-F. At WOT, if it's not stopping at the third step, you have a problem. If it stops at the 2nd position, either your shift arm is bent, governor is mounted incorrectly, or the shift lever needs to be adjusted.

More than likely the last reason, when you shift to forward, the shift arm doesn't open up far enough for the necessary clearance. Check to see if the shift level is seating properly and completely, what i mean is seated in the "3" shaped end of the shift arm. The lever must be engaged in the forward "slot" for proper clearance for the throttle governor

 

[bigroystoys]

Re: 1956 15 hp throttle cam






these are pics of wot in forward, thanks

 

[bktheking]

Re: 1956 15 hp throttle cam

Where did the roller on the cam pic go, where is it in WOT?

 

[bigroystoys]

Re: 1956 15 hp throttle cam






these pics are wot roller, thanks everyone for working on this for me, im stumped on this one

 

[bktheking]

Re: 1956 15 hp throttle cam

That all looks good, that's as far as it should go, butterfly should be full open at that point. There should be a linkage going from the cam to the carb, could it be out of adjustment, loosen the screw and open the butterfly fully and tighten it when the tiller handle is @ WOT.