15hp evinrude 80's model throttle help

[jctexas07]

Hello all:

I just bought a mid 80's model 15hp evinrude 2 stroke. The motor runs great. However, the problem I am having is when I turn the tiller handle to get the motor to rev up, it seems to only be pushing the roller that is on the carb about half way onto the black plate, which I think is the timing plate, not sure really.

So, it seems like the engine is not allowing me to go to full throttle. There is plenty of play on the carb roller, and I can rev up the engine by pulling on the roller by hand, just not by rotating the tiller handle.

Any idea on how I might be able to rotate the tiller throttle and get the timing plate to rotate around enough to push the carb roller back?

 

[Xcusme]

Re: 15hp evinrude 80's model throttle help

Welcome to iboats!

First things first....is the motor in forward gear??? The gear limits the full throttle limit...

Again, welcome to iboats.

 

[jctexas07]

Re: 15hp evinrude 80's model throttle help

thanks, however, it's not the gear that is limiting the throttle. it seems to be that the cam roller plate is not turning around far enough to push back the carb roller to increase power. i can only rotate the handle about a 1/4 turn, and that is it. there is atleast 3 to 4 inches of roller plate that can be rotated and used, just can't access it for some reason when turning the throttle.

 

[mikesea]

Re: 15hp evinrude 80's model throttle help

check that the cam plate under the flywheel isnt broke,there were some different types over the yrs and some had a small adjustment piece that could break off and find itself down in the cowling somewhere,the flywheel will need be taken off to replace it

 

[jctexas07]

Re: 15hp evinrude 80's model throttle help

i double checked the cam plate. it's all in tact. it just won't rotate enough to fully engage the roller forward for more power.

 

[bktheking]

Re: 15hp evinrude 80's model throttle help

i double checked the cam plate. it's all in tact. it just won't rotate enough to fully engage the roller forward for more power.

Sounds like you need to pull the flywheel and lube everything up, over time the tiller and all associated linkages as well as the plate under the mag can dry up preventing you from rotating it.

Also, looking at the motor from the front with the cover off on the left hand side, there is a plastic lockout that rotates when you put the motor in gear. Make sure the lockout is rotating when shifting, it will prevent the mag plate from rotating if something with the lockout isn't functioning, about a 1/4 turn to be exact.

 

[bigfern83]

Re: 15hp evinrude 80's model throttle help

HI GUYS,
I JUST MYSELF A 7.5HP JOHNSON IN JANUARY OF THSI YEAR AND IT SEAMS THAT I MOUNTED IT ON MY JOHN BOAT 2 DAYS AGO TO GIVE IT A TEST DRVIE, BUT NOTICED THAT I HAVE BEEN HAVEING THE SAME PROBLEM WITH THE THROTTLE ACTION. I HAVE NO PROBLEMS TURNING ON THE ENGINE BUT WHEN ROMPING THE THROTTLE, IT SEEMS THAT IT JUST NEEDS MORE THROTTLE THAN OTHER JOHNSON 7.5 MOTOR I'VE SEEN ON YOUTUBE. I TRIED MOVING THE THROTTLE CABLE BY MOVING AN ADJUSTER THAT HAS A THREAD TYPE OF ADJUSTER AND HAD NO LUCK. I FOUND SOME INFORMATION IN REGARDS THE SAME SUBJECT AND IT GIVES YOU TIPS ON HOW YOU CAN FIX THE PROBLEM BY CLEANING OUT THE CARB AND FUEL DISTRIBUTER.

IF YOU HAVE FIXED YOUR PROBLEM PLEASE FEEL FREE TO HELP ME WITH SOME ADVISE ABOUT HOW I CAN FIX THIS PROBLEM.

THANKS:redface:

 

[jctexas07]

Re: 15hp evinrude 80's model throttle help

nothing is binding the rotation of the cam plate and tiller accelerator. it's just not rotating to its fullest rotational potential to get it to wide open throttle, not even close.

 

[bktheking]

Re: 15hp evinrude 80's model throttle help

Did you do the second part of my reply?

Also, looking at the motor from the front with the cover off on the left hand side, there is a plastic lockout that rotates when you put the motor in gear. Make sure the lockout is rotating when shifting, it will prevent the mag plate from rotating if something with the lockout isn't functioning, about a 1/4 turn to be exact.

 

[jctexas07]

Re: 15hp evinrude 80's model throttle help

BKTHEKING, you rock buddy. I see exactly what you are saying now, duh. It does seem like I will need to lube a few of the linkages/controls to get that to smoothly and fully engage full throttle when in gear. I see exactly how it 'locks out' when in neutral and dips down for full engagement when in gear.

What do you use/recommend for lube and do you have any recommendations to where to lube. Thanks again. You rock!

 

[bktheking]

Re: 15hp evinrude 80's model throttle help

This is the lockout, black plastic part with a bolt through it and white round part on the bottom which connect to the shifter.

When you shift the motor into forward the black lockout in the pic pivots allowing the mag plate to move past the lockout plastic piece. If something is broken (which does happen, notice that black lockout is shiny and new) it will not allow the mag plate to travel and only allow for 1/4 throttle. Notice how the mag plate has a notch, if I tried to move the throttle it neutral all the way it would stop against the lockout.

 

[jctexas07]

Re: 15hp evinrude 80's model throttle help

Thanks a mil!

 

[bktheking]

Re: 15hp evinrude 80's model throttle help

To get it working correctly pull the flywheel and remove the mag plate (a few screws hold it on to a secondary plate) I lube around the where the mag makes contact with the block and make sure the friction bearing is clean and grease free (it's not actually a bearing, more of a plastic circle in which the mag plate rides on, check to make sure its in good shape) A marine grease will work. Check the tiller handle gears for good mesh, old worn out gears also make them hard to turn.

 

[bktheking]

Re: 15hp evinrude 80's model throttle help

PS if you don't know about the site on 9.9's have a read:

http://www.sschapterpsa.com/ramblings/Johnson_9.9_troubleshooting.htm

#7 talks about the bearing plate.