Timing off due to throttle arm and cam follower?

awreneau

Cadet
Joined
Sep 23, 2024
Messages
16
Hard to start w/ pull cord but I suspect its due to timing.

'74 Evinrude 15hp (15r74g)

The cam follower does not move until after the timing mark has
View attachment IMG_8379.MOV
moved past it. The washer that sits between the carb housing and the plastic follower was missing so I improvised with a plastic bushing from lowes 'specialty' bin in a hail mary of sorts to see if moving the follower further to the left would improve on the timing. It did, only slightly.

I'm curious if the Throttle Control Cam could be worn in addition to the follower. There appears to be indicators of wear, its shinier than the rest of the arm, and I was wondering if this is a legitimate contributor to the hard start. I can crank easy enough with a drill and a quick shot of ether and it will start and only run if choked. Within the last week rebuilt carb, needle, seat, jet and gasket. I did not change the aluminum plates that cover the idle circuit opening to see if there was trash. Carb was pretty clean when I opened it. Building in a bit of reliability with some preventative maint.

To reiterate, based on the video, attached, is the timing an issue based on the information?

Follower is #32 in this schematic

Control Arm is #37 in this schematic (which is discontinued)

I've attached a picture/video so you can see the follower and arm in action.
 

awreneau

Cadet
Joined
Sep 23, 2024
Messages
16
Added some tape to the cam follower and it starts easier but still with drill.

Pulling is darn near useless

It refuses to idle and still only runs at idle on full throttle or with choke closed.
 

awreneau

Cadet
Joined
Sep 23, 2024
Messages
16
Hard to start w/ pull cord but I suspect its due to timing.

'74 Evinrude 15hp (15r74g)

The cam follower does not move until after the timing mark has
View attachment 401668
moved past it. The washer that sits between the carb housing and the plastic follower was missing so I improvised with a plastic bushing from lowes 'specialty' bin in a hail mary of sorts to see if moving the follower further to the left would improve on the timing. It did, only slightly.

I'm curious if the Throttle Control Cam could be worn in addition to the follower. There appears to be indicators of wear, its shinier than the rest of the arm, and I was wondering if this is a legitimate contributor to the hard start. I can crank easy enough with a drill and a quick shot of ether and it will start and only run if choked. Within the last week rebuilt carb, needle, seat, jet and gasket. I did not change the aluminum plates that cover the idle circuit opening to see if there was trash. Carb was pretty clean when I opened it. Building in a bit of reliability with some preventative maint.

To reiterate, based on the video, attached, is the timing an issue based on the information?

Follower is #32 in this schematic

Control Arm is #37 in this schematic (which is discontinued)

I've attached a picture/video so you can see the follower and arm in action.
I screwed in the
Hard to start w/ pull cord but I suspect its due to timing.

'74 Evinrude 15hp (15r74g)

The cam follower does not move until after the timing mark has
View attachment 401668
moved past it. The washer that sits between the carb housing and the plastic follower was missing so I improvised with a plastic bushing from lowes 'specialty' bin in a hail mary of sorts to see if moving the follower further to the left would improve on the timing. It did, only slightly.

I'm curious if the Throttle Control Cam could be worn in addition to the follower. There appears to be indicators of wear, its shinier than the rest of the arm, and I was wondering if this is a legitimate contributor to the hard start. I can crank easy enough with a drill and a quick shot of ether and it will start and only run if choked. Within the last week rebuilt carb, needle, seat, jet and gasket. I did not change the aluminum plates that cover the idle circuit opening to see if there was trash. Carb was pretty clean when I opened it. Building in a bit of reliability with some preventative maint.

To reiterate, based on the video, attached, is the timing an issue based on the information?

Follower is #32 in this schematic

Control Arm is #37 in this schematic (which is discontinued)

I've attached a picture/video so you can see the follower and arm in action.
Screwed in the slow idle until it seated then backed out twice

just a bit of fyi to accompany my previous reply.
 

awreneau

Cadet
Joined
Sep 23, 2024
Messages
16
I screwed in the

Screwed in the slow idle until it seated then backed out twice

just a bit of fyi to accompany my previous reply.
Did a bit more digging. Seems there is another cam follower that can be adjusted. So, I'll pick up one of those and screw in the cam to match the throttle control arm at the proper time.
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
8,092
The cam has 2 small screws holding it in from the bottom loosen those for your adjustment. The adjustable arm wont work with the recoil safety.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,815
" Hard to start "-----Is usually due to weak spark.----So does spark jump a gap of at least 5/16" on both leads?----And post the all-important actual compression values.
 

awreneau

Cadet
Joined
Sep 23, 2024
Messages
16
" Hard to start "-----Is usually due to weak spark.----So does spark jump a gap of at least 5/16" on both leads?----And post the all-important actual compression values.
It’s running now. Haste makes waste.

When reassembling I put the old needle seat in the place if the jet. When I pulled it all apart it struck me that both were new and it occurred to me what I’d done.

Put it all back together, correctly, and after another good cleaning, and viola.
 

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awreneau

Cadet
Joined
Sep 23, 2024
Messages
16
The cam has 2 small screws holding it in from the bottom loosen those for your adjustment. The adjustable arm wont work with the recoil safety.
I tried the knock off adjustable cam follower and it bolts up but the adjustment hits the carb before WOT. With the adjustment of the cam throttle arm I hope to be in good shape. Thanks for the hint.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,446
That cam follower/roller, is supposed to rotate after it comes into contact with the Cam.
 
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