Who knows of a good Machine Shop???

[VintageRider]

Here's the story morning glory...

I have a CB400f motor that has the cam chain tensioner bolt, busted off inside the case... I have been reading up on this issue as it seems to be typical of this 30+ year old MC... I am reading that I can tap it out and use a Heli Coil which I am not sure what that is... Or have the bolt machined out properly and just replace the bolt and the spring which gives tension to the cam chain... Can anyone give me some solid advice????? Or point me in the right direction?? As soon as I resolve this issue and do a quick rebuild of the top end I will be released from my cage.....

[GsxR1000Ryda]

Here's the story morning glory...

I have a CB400f motor that has the cam chain tensioner bolt, busted off inside the case... I have been reading up on this issue as it seems to be typical of this 30+ year old MC... I am reading that I can tap it out and use a Heli Coil which I am not sure what that is... Or have the bolt machined out properly and just replace the bolt and the spring which gives tension to the cam chain... Can anyone give me some solid advice????? Or point me in the right direction?? As soon as I resolve this issue and do a quick rebuild of the top end I will be released from my cage.....

I'd be interested as well on a good local machine shop. The 600 motor could use a rebuild

[poach]

Here's the story morning glory...

I have a CB400f motor that has the cam chain tensioner bolt, busted off inside the case... I have been reading up on this issue as it seems to be typical of this 30+ year old MC... I am reading that I can tap it out and use a Heli Coil which I am not sure what that is... Or have the bolt machined out properly and just replace the bolt and the spring which gives tension to the cam chain... Can anyone give me some solid advice????? Or point me in the right direction?? As soon as I resolve this issue and do a quick rebuild of the top end I will be released from my cage.....

heli coil--->http://www.emhart.com/products/helicoil.asp?gclid=CJHmmOzC0ZUCFRIcawodTEpxhw

Not sure on the machinist thing...but Ray @ aaw would know...

[hippylong]

i would not heli coil any crank or piston anything..
find out if it's a recall item..
then ..
sears makes 2 types of bolt extractors set..
also keep it soaked with penatrent oil...
also it's better to use impact tools.
because the vibrate as well and thgat breaks rust and electroloisis bonding..

[PRTSMN]

i would not heli coil any crank or piston anything..
find out if it's a recall item..
then ..
sears makes 2 types of bolt extractors set..
also keep it soaked with penatrent oil...
also it's better to use impact tools.
because the vibrate as well and thgat breaks rust and electroloisis bonding..

:word: What he said..:D

[Don Hopkirk]

If it is just a cam chain tensioner bolt, a heli-coil should work fine, that is if the threads are actually ruined. Not sure I would recommend using any type of extractors, they are usually hardened and if they break the only way to remove them is with an EDM machine. I would try to flatten or grind the broken area of the bolt then center punch and drill, starting with a drill that is smaller than the diameter of the bolt (very important to center punch the exact center of the bolt prior to drilling). If you still need some help or are not comfortable doing this yourself, post a picture of the part that needs to be fixed I may be able to help. Depends on how big the part is, the boss frowns on lugging in large things or time consuming projects, but if it is fairly simple I can get away with it. Also if worse comes to worse we have an EDM machine where I work.

Don Hopkirk

[Matt07drz400]

Well I know first hand that there are reverse dillbits that after u center punch the bolt u can dill with these bits and it will pull the bolt out... I dont know where to get them my dad had a set but we can not find but they are a rebulider best friend when u break a bolt... there is a machinst in madera who resurface the head of are truck a few years back that is awesome and well i could look for him again if u need it... he is located in madera though...

[Don Hopkirk]

Well I know first hand that there are reverse dillbits that after u center punch the bolt u can dill with these bits and it will pull the bolt out... I dont know where to get them my dad had a set but we can not find but they are a rebulider best friend when u break a bolt... there is a machinst in madera who resurface the head of are truck a few years back that is awesome and well i could look for him again if u need it... he is located in madera though...

You could also go with a left handed drill bit, in some cases the heat from drilling will back the bolt out saving any need for a heli-coil. Again make sure to center punch the exact center or the drill will walk and ruin the threads. Unfortunately bolts don't usually break leaving a flat surface to center punch. If the surface to be drilled is uneven you will most likely have to clamp the part in a bridgeport and use an endmill to flatten the surface, then centerdrill the bolt followed by drilling just under the minor diameter of the bolt. Once this is done you can usually remove what is left of the bolt and chase the threads with a tap.

Don Hopkirk

[yoageallen]

I could get it out for you if you take it apart.

[CRASH972]

If the bolt didn't break off to far in the block you can weld a nut to it.
The heat & some rust pent will help w/removal.

[JustinCoffman]

i know a great machine shop why

[up in smoke]

i know a great machine shop why

exactly

[aaw749r]

I have a left handed drill bit set and good extractors.
Show us a pic. Can get most anything out if it is accessable.

[hippylong]

:worthless:

[VintageRider]

Here's a pic, not my bike but same exact place and problem... Thanks in advance for the advice and the help... And yes upon doing some more research and asking some questions... I did find out that helicoil, timesert, should be the last options... We are going to take apart the top end and get down to the crank case to see if there is some thing we can do before getting a drill involved...

[hippylong]

Here's a pic, not my bike but same exact place and problem... Thanks in advance for the advice and the help... And yes upon doing some more research and asking some questions... I did find out that helicoil, timesert, should be the last options... We are going to take apart the top end and get down to the crank case to see if there is some thing we can do before getting a drill involved...

is it all countersunk?
(can't tell by pic)
i have a friends extractor set.
but it has to be above surface.
made by craftsman.
irioncaly it's made to remove nuts.
but i've used it to remove bolts..
29.95 sears

[VintageRider]

Sure is maybe by an 1/8" of an inch or so, could be more... no more then a 1/4" though

[hippylong]

craftsman extractor.
we can try i'm off tomm.