Help with refitting Johnson 25hp flywheel required,please

[jmaw]

I took the flywheel off to investigate why the armature plate was moving up and down when the engine was running<br />and whether or not this was causing the engine knocking noise I was concerned about.<br />The flywheel was catching one of the coils and after adjusting the coils position, I refitted the flywheel and started the engine up,knocking noise (like a bad bearing) still<br />there, I pulled the spark plug lead off the <br />lower plug with no change in engine noise,<br />(no spark at lead,) sorted that out, and restarted the engine expecting that to have cured the knocking noise, but it had'nt,got pissed off and left it alone for 2-3 weeks.<br />Yesterday I tried starting it and had to struggle to get it started, normally it will start 1st or 2nd pull,even though it sounds rough when its running,kicked back once and hurt my wrist, when it did start it only ran for 4-6 seconds then sheared the flywheel key.Ordered new key but cant get it till middle of next week,my questions are (1) how<br />far down the taper on the crankshaft should the flywheel actually sit? mine seems to sit<br />about an eight of an inch up from the flat part on the crankshaft if that makes any sense to you.I've lapped it a bit with grinding paste but dont want to overdo it in case thats how its supposed to be. (2)should there be a washer under the flywheel nut? I,ve now got a Clymer manual but it does not <br />show a picture.<br />(3)There's a slight side to side movement in the crankshaft thats probably causing my noise (1-2 thou.any thoughts on that appreciated. Thanks Jim Maw

 

[clanceley]

Re: Help with refitting Johnson 25hp flywheel required,please

Gday Jim,you didnt say how old your motor was ,but the noise you are experiencing with the motor sounds like one of my problems I was able to solve with my 1966 20hp Johnson.If yours is the same set up, this might help.<br />The plate the ignition sits on is held in place by 4 metal threads going into an aliminium ring which is held in place by a brass plate fastened to the crank case by three metal threads. I got some shim material, about .1mm, and cut a flat washer to go between the ignition plate and the brass plate, and it took out the free play that had been evident.The motor is much quieter now,which really surprised me, such a simple thing. I cant really help you much with the position of the fly wheel, but it sounds as if you didnt have it sitting down properly for it to shear the key way.On my motor, the flywheel sits directly on the collar of the crank, and there is a thin metal washer (which covers the three holes for pulling the flywheel off with) that goes under the nut for securing the flywheel in position.Good luck.<br /> Clanceley