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Johnson 55HP Throttle Cam Screw Severed. Help!

jasondainter

jasondainter

Regular Contributor
Hi Folks.

I have a Johnson 55HP from 1980 (engine model 55EL80C).

I was reassembling the carburetors today and to do so I had to reattach the throttle cam (part 319835 or #48). When screwing it back in I noticed that it didnt seem to be going into the hole enough so that the washer (#33 below) was snug with the the bolt (#32 below) (the washer was quite loose on the bolt so clearly didnt look right).

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So I reluctantly tightened the screw some more with a bit more force, and of course, it severed of the head. Now it looks like this (below). I attemped to screw a pilot hole down the middle, it's pretty damn tough this screw but obviously would like to try to get the severed bolt out without wrecking the theads. I stopped there to consult with you experts before doing anything more!...

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I have a set of "easy out" screw removers (they look like this) but not sure if theyll be much help here.

I managed to find a replacement bolt (#32) which can arrive in 5 days or so but my mission now is to get that bolt out without damaging the threads.

If I damage the thread getting it out Im guessing an option would be to tap a larger hole, but then that seemingly quite spe******t bolt wont fit so I'd rather try to avoid that as that would seem to add to my problems.

Any ideas on how I get out of this mess?

Thanks ahead.
 
OK so those easy outs I bought on wish.com were worth every cent! Took the severed bolt thread right out (made it look easy, quite impressed!) so my problem got a little bit easier.

Now I'm wondering:

1) Does anyone know what the size of that bolt thread would be to tap that if I needed to (still worried it may need tapping out). I only have metric taps (live in Sweden) so I'd need to and buy an imperial tap. For part #32 (part 316037).

2) Does anyone know why it might not have gone in fully in the first place? The bolt came out finr when I removed it so I'm trying to figure out why it didnt go in all the way in order to avoid the mayhem above again.

Thanks.
 
In all probability the screw threads are the normal 1/4x20... but why not wait for the replacement screw to arrive. If the original broken portion came out easily as you state, it's unlikely the threads need reworking.
 
Thanks @Joereeves. Yes that makes sense, the part did come out quite nicely and I dont think I drilled into the threads luckily.

The reason Im concerned I may need to tap them is because the fact the bolt didnt go in when I tried in the first place. I'm a bit stuck on why that was actually. since the bolt came out easy enough but when it went back in it had a notable gap perhaps 2mm or so where the thinner washer (#33) seemed to hang loose on the bolt. In giving it more force I managed to wreck the bolt.

I could wait to try again I guess with the new bolt when that comes. Worst case if I wreck it again at least I know how to get it out now :) But quite pricey, the bolt set me back about 22 USD (to Sweden), plus the delay sucks as i'm trying to get the boat in the water before the rare Swedish sun dissapears!

I measured the part that came out, the diameter (measuring from the widest edge to widest edge if that makes sense) was 1/4" as you suggest so I think that probably answers my question.

Will probably get a set of imperial taps anyhow, I have a feeling I'll be needing them again in the future.
 
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