25E72R cam follower question

hardwater fisherman

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Does this cam follower sleeve look worn down? I have it set that the throttle plate starts to move at the first of the 2 marks. And when the mag plate goes around and hits the stop the throttle plate is fully open. The reason I ask this is because I have not seen one of these sleeves before. I think all of my other motors have rollers or just a solid plastic cam follower.Edit I had to push the cam follower back very far and tighten the screw to make contact with the mag plate cam.
 

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F_R

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I'd say if it is doing the job it is supposed to do, then it's fine.
Actually, I don't remember seeing such a sleeve. I remember rubber rollers. But I don't have memory that perfect.
I'm thinking the cam moves in/out to adjust the pick-up point.
 

hardwater fisherman

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The way it was before I moved it back ,it was not even touching until an inch or so past the marks. So I figured that was not right.
 

Chinewalker

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Is there supposed to be a return spring on those? I know there is on some other smaller models. Almost looks like there's a small hole in the crankcase webbing directly behind the cam follower. In any case, the follower should return to full throttle stop on its own - you shouldn't have to push it back.
 

AlTn

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the spring for the cam follower is on the throttle shaft...the follower <sleeve> should be between the 2 marks on the timing cam when the throttle grip is advanced to the neutral stop for starting, then rises to the highest point on the timing cam when the motor is in forward gear and the throttle is at wot position....the throttle plate should barely open in the start position then goes to a perfectly horizontal position in the carb throat at wot...anyway, that's what you are trying to achieve...I have a '72 model 25 and the cam follower is always in contact with the timing cam even at the lowest idle setting
 

Joe Reeves

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On that 1972 25hp model (and many others), the throttle roller is smaller in diameter... approximately 1/8" or so and is a one piece roller.
If you have purchased one that is approximately 3/8" in diameter and consists of a small black plastic roller that has a clear sleeve covering it... you have the wrong roller which is used on much later models.

You need roller part number 305232
 

racerone

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Post # 1 appears to show the correct roller with little to no wear on it.
 

hardwater fisherman

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the spring for the cam follower is on the throttle shaft...the follower <sleeve> should be between the 2 marks on the timing cam when the throttle grip is advanced to the neutral stop for starting, then rises to the highest point on the timing cam when the motor is in forward gear and the throttle is at wot position....the throttle plate should barely open in the start position then goes to a perfectly horizontal position in the carb throat at wot...anyway, that's what you are trying to achieve...I have a '72 model 25 and the cam follower is always in contact with the timing cam even at the lowest idle setting

With the motor in neutral the follower makes contact at the marks, as shown in the first photo. And if I advance the throttle until it hits the stop,it as shown in the second photo.
 

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Joe Reeves

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With the motor in neutral the follower makes contact at the marks, as shown in the first photo. And if I advance the throttle until it hits the stop,it as shown in the second photo.

That would normally hold true "IF" the unit was in NEUTRAL due to the shift lockout mechanism. If "IN GEAR", the timer base shoul;d continue to turn to have the larger portion of the cam pushing the roller, and thus the butterbly, to full throttle
 

jose cuervo

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Hardwater fisherman , I just signed up here and don't really know how this works but I have just came into a 25R72R and I am unsure about a small rubber line that comes out on the starboard side just forward of the top sparkplug . Could you look at your motor and tell me if it goes down to the front and connects to a nipple in the front bottom , Please .?
 

hardwater fisherman

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That would normally hold true "IF" the unit was in NEUTRAL due to the shift lockout mechanism. If "IN GEAR", the timer base shoul;d continue to turn to have the larger portion of the cam pushing the roller, and thus the butterbly, to full throttle

Yes when in forward gear and throttle is advanced, the throttle plate fully opens. I just was not sure about when it should start to open. But it seems I have it correct. Thanks.
 

hardwater fisherman

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Hardwater fisherman , I just signed up here and don't really know how this works but I have just came into a 25R72R and I am unsure about a small rubber line that comes out on the starboard side just forward of the top sparkplug . Could you look at your motor and tell me if it goes down to the front and connects to a nipple in the front bottom , Please .?

I made a post about this before. The line does go to the manifold under the carb.
 

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AlTn

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if the carb opening to timing advance shown in your pics yields a slightly open throttle plate at full neutral start advance and then goes to a full horizontal plate at wot and the mag plate is as advanced as it can be,then all is well...on mine, the roller is between the 2 timing cam marks when the throttle is advanced against the neutral start stop...if your mag plate can still be moved manually at the wot position, some adjustments are still needed, otherwise you are good to go
 

Joe Reeves

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Yes when in forward gear and throttle is advanced, the throttle plate fully opens. I just was not sure about when it should start to open. But it seems I have it correct. Thanks.

There is a scribe mark on the cam.... the throttle butterfly should just start to open when the scribe mark is dead center with the roller.
 

hardwater fisherman

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if the carb opening to timing advance shown in your pics yields a slightly open throttle plate at full neutral start advance and then goes to a full horizontal plate at wot and the mag plate is as advanced as it can be,then all is well...on mine, the roller is between the 2 timing cam marks when the throttle is advanced against the neutral start stop...if your mag plate can still be moved manually at the wot position, some adjustments are still needed, otherwise you are good to go

Okay thanks. I think it is correct.
 

hardwater fisherman

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There is a scribe mark on the cam.... the throttle butterfly should just start to open when the scribe mark is dead center with the roller.

There are two marks so I will set the roller in between them.
 

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