Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: MikeM on May 23, 2014, 09:16:54 AM

Title: engine stud
Post by: MikeM on May 23, 2014, 09:16:54 AM
has gone pop

clean break and no way of gripping with anything, must be  2mm recess

So speaking to bryan a drill job again.... what size helicoil for this one  ::)
Title: Re: engine stud
Post by: matthewmosse on May 23, 2014, 10:06:09 AM
Whereabouts has this one gone? exhaust? m6 again. I feel your pain, had a few go, expect I'll see a few more soon and I know I have 1 engine where a previous owner has drilled out to m8 and made a mess of it - not looking foreward to fixing 3 of them.
Title: Re: engine stud
Post by: MikeM on May 23, 2014, 10:17:37 AM
exhaust stud , where you bolt the exhaut collar on, no 1 cylinder

last bolt i was tightning and it gave up
Title: Re: engine stud
Post by: matthewmosse on May 23, 2014, 03:42:44 PM
Typical :(
Title: Re: engine stud
Post by: Bryanj on May 23, 2014, 07:53:14 PM
M6 helicoil standard depth mate
Title: Re: engine stud
Post by: MikeM on May 23, 2014, 08:26:04 PM
least I have all the correct stuff to fix........

what about swarf going into engine is that going to be likely outcome ? ..... any tips to avoid that.... just done a top end rebuild and don't really want to start pulling the head
Title: Re: engine stud
Post by: Bitsa (Ralph Wright - RIP) on May 23, 2014, 08:27:10 PM
Thats as bad as the last cam tower bolt.Do it up and it strips right pain in the butt
Good luck
Bitsa
Title: Re: engine stud
Post by: Bitsa (Ralph Wright - RIP) on May 23, 2014, 08:29:13 PM
Make sure the exhaust valve is shut on that cylinder then when repaired air it out
Cheers
Bitsa
Title: Re: engine stud
Post by: Trigger on May 23, 2014, 08:53:36 PM
I use milk carton/ container tops. The round ones fit nicely in the port holes. 
Title: Re: engine stud
Post by: Trigger on May 23, 2014, 08:57:10 PM
Just emailed you a picture on how to use the tops Mike.
Title: Re: engine stud
Post by: matthewmosse on May 23, 2014, 08:59:05 PM
and put a bit of tape around the drillbit at the right depth as drilling right through to the inside is really not reccomended unless you like the engine to get coated in oil.
Title: Re: engine stud
Post by: MikeM on May 31, 2014, 03:04:24 PM
well I drilled in with m6 drill, tapped and heli coiled and sure I have done something wrong

drilled in length of bolt that snapped, not gone all the way through ( should I )

tapped it m6 by 1mm tap and then put in helicoil, stud replacement set( bought of ebay ) when you put in stud it pulls out helicoil

any recommendations... this is last part of bike and this is not right I can nearly pull out helicoil with my fingers


just noticed m6 tap just slides into hole :-\

getting close to  splitting this bike  :-\

Title: Re: engine stud
Post by: ka-ja on May 31, 2014, 04:07:11 PM
Hi,
    Is the tap a 6mm tap or a 6mm helicoil tap?
Title: Re: engine stud
Post by: Bryanj on May 31, 2014, 04:30:20 PM
If the helicoil pulls out you can search keensert or timesert which have a bigger outside diameter
Title: Re: engine stud
Post by: Trigger on May 31, 2014, 05:31:37 PM
O dear Mike, there is only 2 ways now. Go with a insert as Bryan has mentioned or if you know a good aluminum wielder that can do the job.   
Title: Re: engine stud
Post by: MikeM on May 31, 2014, 06:19:51 PM
6mm helicoil tap that came with kit

put a bid of threadlock round helicoil and put it back in

does not look promising the tap just slides in now cant cut it any more .... gutted

 tried to put exhaust back on and nope just pulls out helicoil stretches it

so need another plan...... the walls of the head are not cut, almost like the tap has just made it smooth and not actually cut a thread,   
Title: Re: engine stud
Post by: Bitsa (Ralph Wright - RIP) on May 31, 2014, 07:02:14 PM
Mike
No big deal do as Trig says find a good ali welder and re drill it to size lucky for me I have a good english ali welder here and has done a couple of jobs for me with great results
Cheers
Bitsa
Title: Re: engine stud
Post by: MikeM on May 31, 2014, 07:07:56 PM
 :-\ couldn't find an ali welder round here for last job.... had to come up with different plan last time

gutted about this was looking forward to starting bike tomorrow
Title: Re: engine stud
Post by: ka-ja on May 31, 2014, 07:08:17 PM
Hi,
    how much "meat" around the stud hole? not familiar with your motor, just wondering if it is possible to tap out 8mm., then use an 8mm/6mm double diameter stud, even 7mm taps are available, seems a same to waste an otherwise decent head, are you near humberside?---ken
Title: Re: engine stud
Post by: Bitsa (Ralph Wright - RIP) on May 31, 2014, 07:16:23 PM
Ka Ja
Just emailed Mike with more or less the same solution we all know when this happens it knocks the crap out of you.
Cheers
Bitsa
Title: Re: engine stud
Post by: ka-ja on May 31, 2014, 07:23:39 PM
hi,
    If he was near, I could maybe have helped, yes, it is gut-wrenching,been there!----ken

     This one got to me, seized in gallery plug, and asoda blasted engine to clean!

                       

                     
Title: Re: engine stud
Post by: Trigger on May 31, 2014, 07:46:54 PM
Mike there must be someone in your town that has a Tig wielder. If you put the stud in and then tack around it to make sure it is true, then tig it in.
Title: Re: engine stud
Post by: MikeM on May 31, 2014, 08:05:03 PM
put up an ad on local motorcycle club so will see what comes from that first

(http://i974.photobucket.com/albums/ae228/INEEDMOREPICS/PICT0387_zps54f863f3.jpg) (http://s974.photobucket.com/user/INEEDMOREPICS/media/PICT0387_zps54f863f3.jpg.html)

(http://i974.photobucket.com/albums/ae228/INEEDMOREPICS/PICT0386_zpse815eff7.jpg) (http://s974.photobucket.com/user/INEEDMOREPICS/media/PICT0386_zpse815eff7.jpg.html)

at least I know some options now
Title: Re: engine stud
Post by: Bitsa (Ralph Wright - RIP) on May 31, 2014, 08:23:45 PM
Mike
From the pics definatly fixable chin up mate
Cheers
Bitsa
Title: Re: engine stud
Post by: paul G on June 01, 2014, 09:07:49 AM
I would go the 8mm to 6mm stud rout, loads on eBay.
Title: Re: engine stud
Post by: ka-ja on June 01, 2014, 09:30:40 AM
Hi,
    Enough metal there to carefully tap out 8mm-good luck----ken
Title: Re: engine stud
Post by: matthewmosse on June 01, 2014, 02:51:36 PM
I have a cb500 engine where someone has done a few out to at least m8 and it looked like an attempt at m10 had been made, though that is a bit silly and I'll be fixing it with welding. For yours, re tapping to m8 would seem best.
Title: Re: engine stud
Post by: MikeM on June 01, 2014, 09:31:34 PM
any links to the m8 to m6 exhaust studs

can find m8 to m10
Title: Re: engine stud
Post by: MikeM on June 18, 2014, 10:05:43 PM
well after trying countless engineering firms not one local firm wants to take it on

so storage for bike until I can find an answer  :-\
Title: Re: engine stud
Post by: matthewmosse on June 18, 2014, 10:27:35 PM
I'm surprised at that, ok it is a bit of a pain of a job, but it isn't un surmountable - want me to chat with my mate who runs a bike shop? he might be able to sort the head out if you sent it down here.
SimplePortal 2.3.5 © 2008-2012, SimplePortal