RXS100 stripped exhaust stud repair

[Serendipity]

My old ’86 RXS100 developed a problem that required removal of the exhaust downpipe. At some point in the bike’s past someone had replaced the original studs with poor quality bolts and inevitably one snapped during dismantling. I ended up drilling it out, but slightly damaged the thread in doing so. I fitted new studs and put the bike back on the road, but some time later I realised that the downpipe wasn’t sealing properly. The thread had completely stripped on the one stud so the bike went into storage until I could be bothered to sort out a permanent fix.

Last week I picked up a helicoil style thread repair kit from Ebay and thought I’d share how I got on.

Apart from the wire inserts themselves the kit comprises of drill to expand the hole, tap to cut the thread for the wire insert, tool to insert the wire and punch to break off the tab on the wire insert.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4959a.jpg

This is the hole with the messed up thread.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4956a.jpg

I started by drilling out the hole. Although the picture shows a full-on electric drill I quickly switched to a cordless drill/driver because it offered much more control over the speed. I’m a lazy sod and decided to fit the helicoil without putting the engine on the bench. Normally I’d recommend using a bench mounted pillar drill for accuracy, but I was taking a short cut here and it was obvious that the high speed, hand held drill was going to chew through the soft metal of the barrel in seconds. Hence the switch to the cordless driver. Yes, I know that the frame needs a lick of paint.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4964a.jpg

This is the resulting (slightly out of focus) hole. Not much better than when I started.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4966a.jpg

The shiny new tap. Note that the tap wrench is not included in the helicoil kit. I used one I already had.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4969a.jpg

Then the first show stopper hit me. There wasn’t enough clearance between the frame rails to turn the tap wrench. A quick bit of desperate thinking came up with this bodged extension bar and I was back on track.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4970a.jpg

The newly tapped hole. The wet look comes from spraying loads of light oil to lubricate the tap and wash out the swarf as it cut the thread.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4971a.jpg

This is the insertion tool.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4973a.jpg

There is a slot on the tip into which a tang on the coil fits so you can screw the insert into the hole.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4974a.jpg

And there you have it. A brand new, steel thread in a soft alloy engine part.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4976a.jpg

The only thing left to do is use the punch to beak the tang off the insert. The barrel on the RXS is tilted forward so the tang just fell out once broken off.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4977a.jpg

Hopefully the stud is secure now. If it gives out during tightening this time it’s time for a new cylinder.

https://i221.photobucket.com/albums/dd227/serendipity_uk/RXS100/IMGP4978a.jpg

I’ll let you know if it holds.
____________________
2016 CBF1000F - Commuter heaven | 1994 CBR600FR - Awaiting defibrillation

[alun111]

Excellent write up - will come in handy if I ever need to attempt a repair like this in the future. Cheers!
____________________
Summer: '00 Honda CB600F Hornet
Winter: '93 Suzuki GSF 400 Bandit VP Variable Valve
Past Bikes: Lifan LF100-5 Lifan LF125-A Honda C70

[Damon]

Great write up, I thought you were just going to drill out the hole and re tap it using a bigger size tap + fit a bigger bolt to hold it all together.

How much are those helicoil kits?

[Serendipity]

[Odie]

Nice write-up,
I have used heli-coil kits for years, exellent bit of kit, pity they only do one size per kit!
____________________
You are so ugly when you were born the doctor said "I?m gonna drop it, if it falls is a rat, if it flies is a bat."

[Fnatic]

Nice write up and cheers for this Nice quality camera also.

[reu]

would of helped and just gave a bit more security if u had of put lock tight on it but owell.
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125cc Pitbike <sold> Aprilla Mx50 <current>

[K0rnIsAFAGGOT]

Yeah i would of also used some lock tight for that extra bit of security.
Great write up, very helpful if i ever need to do this.