johnson 15hp 1983 plate under flywheel loose?

[apark999]

hi, my 1983 johnson 15hp runs irregularly at high revs.<br />when i engage forward gear and advance the throttle the plate under the flywheel (which the throttle cam roller runs against) moves of its own accord both advancing and decreasing the revs.<br />is it possible that this is just loose and i need to tighten a nut/bolt?<br /><br />thanks guys any help appreciated<br />Alex

 

[WillyBWright]

Re: johnson 15hp 1983 plate under flywheel loose?

You mean it moves all by itself? Or in unison with the throttle?

 

[apark999]

Re: johnson 15hp 1983 plate under flywheel loose?

it seems to move by itself??? it just all seems very loose to me, i havent had the flywheel off as yet (mainly cos i dont have a puller). but if you sit and watch it it moved back and forward.<br />the throttle could do with tightening up slightly from the tiller arm but its not as loose as the plate?<br /><br />any help?

 

[OBJ]

Re: johnson 15hp 1983 plate under flywheel loose?

Alex....with the engine not running, shift into forward and advance the throttle to wide open throttle. See if you can reach up under there and move the plate by hand. Watch the throttle linkage on the port side of the engine while doing this. Any movement could mean that some part of the linkage from handle to the plate is lose or worn out.<br /><br />Pop the flywheel and see if there is any back and forth slop where the plate goes down over the large round area on top of the block. Any back and forth movement may mean the bushing in the center of the plate is wearing out...kind of a common thing.<br /><br />Also check the phillips head screws that hold the plate to the retainer plate.

 

[apark999]

Re: johnson 15hp 1983 plate under flywheel loose?

Thanks OBJ, i removed the starter coil to get a better view og the throttle linkage and saw that where the tiller cog meets thevertical part of the throttle shaft(the bit with the teeth) this was fairly loose, but when in forward and WOT i couldnt really shift the plate by hand and there was little if any play.<br />it seems as though it only does this whilst engine is running at high revs.<br />i havent been able to pull the flywheel yet (ive only got a small socket set) have to go to hardware store, but i'll update as soon as i have checked.<br />Thanks again<br />Alex

 

[hisey1]

Re: johnson 15hp 1983 plate under flywheel loose?

i used a harmonic balance steering wheel puller on my flywheel that cost $8 at autozone. (after i got the nut off that is) also, leave the nut turned down a few threads because when the flywheel finally lets go, it will probably do so suddenly and violently and you dont want it flying off there and breaking the magnets loose or hurting yourself. hope this might help a little. good luck and be patient with that flywheel.