There was a reason I didn't run the lake at Kosh this past weekend, the '58 Johnson RDS20 just wasn't running right, anyone with any experience knows the feeling, something is just wrong.
So today I pulled the top to change coils and points, well...sorta. Got ready to pull the top off, I use my torque wrench to pull the cap so I know the ft. lbs. when she's about ready to ping.
Pulled about 60 ft. lbs. and let it sit for about 20 minutes to work, put some more torque on the wrench and it never went over 60. Did this over about 5 hours, a little at a time and still never got over 60. Something goofy here so I just started pulling on the wrench and the cap is coming up real slow but stiff. Finally raised it off by hand only to find that the cap separated from the center, metal just broke apart.
Looking at it I see some PO modified it somehow, tapped and threaded holes for some reason and really weaken the area. So now I have a problem, the center of the cap is solid on the crankshaft and no way to pull it off. I decided to take the Dremel and cut a slot to weaken it.
Got the rest of the soft stuff off and now the hardened steel inner (race?) was cutting through and then the 35 year old Dremel went kapoot. Go figure! Have to visit Harbor Freight to pick up a $25 special to finish the job. I do have a spare cap for this puppy. If you look you can see that the PO or whoever worked on it didn't even tighten down the coil screws.
Thinking someone might have used locktite on the crank.
Youch and I thought just shearing the key off was bad!!!! Well if they did use locktite you're probably going to have to heat it to loosen it. Should help it pop anyway. PO obviously didn't know what they were doing.
Who would have thought trouble was hiding. Guess itâs hard to know true history unless you get to talk to the person you buy it from and also if you know them or their handy skills. Itâs in good hands now.
With our short summers, I can see why you are wasting no time getting your motor Sea worthy as soon as possible. Sounds like a decent price on that flywheel. This hobby is a great excuse for a new tool every so often.
Got the "new" flywheel in the mail today from ebay. Perfect fit and right part number. Gave me a good opportunity to put in new points et al. Surprised to find that the torque on the wheel is only 60 ft. lbs. Turned the motor over and it fired so I shut down right away. Won't have time to do a water test until next Tuesday. Honey-do list is getting long. It cost the same for the guys free shipping than what he asked for the wheel.
Put a hose on the LU today and fired up. It ran for about 40 seconds and then sputtered to a stop. NO GO NO MO.
Checked the point gaps through that little hole and everything was good, fuel delivery good also. Pulled the flywheel to find that the wheel spun on the crank. Sheared the key. Guess I should have expected that since the old wheel was cracked and whacked. The old key was "welded" into the keyway. Took hours to drill and punch it out, harbor freight rotary tool back to the rescue. Found another key on eBay.
I guess I nailed the title of this thread.
Be sure you "lap in" the replacement flywheel to the crankshaft taper. I would use fine valve grinding compound for that task. The crankshaft taper must be perfectly smooth to seat against the internal taper of the flywheel. Any material welded-onto the crankshaft from the old flywheel is unacceptable. Otherwise it'll continue to shear flywheel keys.
You should be able to pick up some valve lapping compound (i.e. "Clover" brand or equivalent) at most auto parts stores.
Great info. I have a flywheel to swap in the fall so I can covert to electric start by installing the same model and year from a blown electric start motor with the teeth. I can now better understand how bad mismatched surfaces allows way more stress to transfer to that key.
Thanks for the info. I did not do that. I'll be stopping at AutoZone today anyway. Should be able to pick some of that up...â¦..
Note, I did pick up a tube of lapping compound from AutoZone, the Permatex stuff. Never used it before so didn't know what to expect. First surprise was when I used the cap to puncture the seal on the tube,...gusher....didn't expect it to be so thin. Smeared some on the crank and then put the flywheel on, spun it back and forth, around in circles etc. you can feel it getting clean. Cleaned it all up with a damp cloth and compressed air. Now that wheel seems to sit tight and lower, can turn it on the shaft without any binding at all.