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Case bolt whoopsies

Started by Striker1423, November 14, 2021, 09:15:45 AM

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Striker1423

So I got a set of stainless Allen bolts for the motor and when I assembled the clutch cover last time the bottom threads seemed tight on one of the holes. It sinched down fine so I thought nothing of it. Until I had to take it back apart when shipping the crank off.

I think what happened was there was some fine mesh glass bead in that one hole. But the bottom 3 threads of the bolt were mashed really flat and removing the bolt became a creaky squeaky chore.

So I think I need a thread chaser as well as a new bolt. Anyone recommend a sufficient tap for this job? Also I tried flushing the hole out with brake kleen and nothing came out that I saw.

DesmoDrew

I have these.  They do fine.  A 'bottom' tap will work also, but that is more likely to remove more metal than necessary.

https://www.rockymountainatvmc.com/parts/bolt-thread-chasers-p

OnlyCrimnson

I would order a bottom tap if the threads seem bad at the end. Use a lubricant and go slowly making small turns then backing off. Then flush the hole again and hit it with the air nozzle to clean it out. I think it's M6x1? Someone please correct if that's not right.

Jspooner

M6x1 is correct. I chase all mine (as needed) with a tap, you shouldn't need anything special, just be careful when starting as it can be real easy to cross thread in aluminum.
"Just quit brain fucking it and get it done"

pdxjim

I always lube them holes with a q-tip dipped in motor oil during assembly. If the come out dirty or swarfy I clean or chase the threads as need be

I suppose you could use a dab of anti seize but that seems like overkill
Wasting time on 2T forums since the dawn of the internet. '89 TDR250, '13 300xcw, '19 690smcr, '56 Porsche 356A

pidjones

I think that after cleaning up the threads,  I would go with a little bit shorter bolt (t stay away from the damaged threads). You probably went further than needed with the SS, and ripped some aluminum out with it. Lube the SS bolts with anti-seize and avoid over-tightening.
"Love 'em all.... Let GOD sort 'em out!"

teazer

First, Flush with wd40 and take a 3/16" drill and carefully clean to the bottom of the threads.  Then use a tap to clean the threads and after that flush the hole out with WD40 again and last but not least, lightly countersink the hole.

The reason for that is that when a bolt is tightened, it will tend to pull the threads up slightly along with the surrounding metal.  If you carefully draw file and case with a new clean fine cut file, you will see raised donuts of aluminum around most of the threaded holes.

m in sc


Striker1423

The thread chasers Desmo Drew mentioned just arrived yesterday. I'll try that before I stick a tap down the hole. Here's to the next several weeks of work. Gotta reclaim the garage as my territory first.
Dad told me about this song and I thought he was joking...
https://www.youtube.com/watch?v=BCV6paTXyCU

Apparently I was wrong haha.

m in sc

i also like to run a small washer under the head bolts.

i mean, these are cheap.  https://www.mcmaster.com/98690A113/

rodneya

Quote from: m in sc on November 22, 2021, 09:30:38 AM
i also like to run a small washer under the head bolts.

i mean, these are cheap.  https://www.mcmaster.com/98690A113/

I bought a set of stainless bolts off ebay from alloyboltz for my Katana and they came with stainless washers. Not quite as thick as the ones in the link. Ive never seen a two stroke motor set that includes washers.

sav0r

I like the alloyboltz kits., I've bought them a few times. Washers are good on any wear surface that is permanent. Especially with these vintage pieces of junk that we all love.

You have to be careful with anti-seize. It allows for higher torque with less effort. This is a good thing in most cases, but in something like an aluminum thread it can get you in trouble real fast. Obviously OP faced a different issue.
www.chrislivengood.net - for my projects and musings.

85RZwade

I think it's clear that the OP has issues...wait, you said faced issues. My bad  :devil:
I post waayyy too much

Striker1423

Quote from: 85RZwade on November 22, 2021, 04:29:15 PM
I think it's clear that the OP has issues...wait, you said faced issues. My bad  :devil:
:busey:

LOL