Crank Case Bolt problem

[Falco]

Hi Guys,

I'm a relatively new biker (~ 2 months) and despite a litany of small (but not crippling issues) I am very taken with the freedom granted by motorised transport.


When I went to check the valve clearances a few days ago, I ran into a problem.
The 6mm hex bolt on the left hand crank case of the CG 125 was stiff but came out no problem. The 10mm one however did not move until it suddenly the head began to mangle at not much more pressure than the 6mm needed (not sure about the terminology, the part of the bolt that the hex fits into on the top of the bolt?).

There is still *some* grip with the Allen key, but I don't want to try again and destroy the head completely. Is there a way I can loosen it before I try again? Or does it have to be drilled out? can a recessed bolt even be drilled out?

Any help appreciated

[mentalboy]

Do you mean an Allen bolt?
https://go.3dlogix.com/exchange/images/uploads/10034-00157.jpg

Firstly check the condition of your allen key - if it has signs of rounded edges bin it and buy decent ones or else you're just setting yourself up for a beating.
Next clean all crud out of the head so that the correct size key fits.

A pic of the offending head would help as it may be beyond removal with the proper size key. Sometimes you can drive a splined torx style needle bit into the head and use that, very much depends upon the damage.

[Jewlio Rides Again LLB]

Liberal application of plusgas under the head into the threads as best you can.

Then, if you can get one into place, impact driver.
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HAHAHA HAHAHA Blew Chilly MyCrowSystems

[Pete.]

Post up a photo. It's hard to visualise what exactly you are struggling with.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Falco]

[monkeybiker]

[smegballs]

I think you have been afflicted with the classic fasteneur du fromage. It's quite a common ailment, especially on 80's bikes with crosshead screws.

[Falco]

Attached a picture of the bolt. The scraping down to the edge of the case from the bolt is unrelated (it came with the bike).

[smegballs]

How about getting a 12/13mm headed bolt and filing the head down to get it a very tight fight, as in "need a light hammer tap to seat in the recess" tight. Then turning said bolt using two nuts tightened against each other.

Alternately, using a longer bolt, file the bolt head to fit. Then heat the bolt shaft and bend 90 degrees to make you a turner.

Similar to this here, only with a hand-fitted bolt head.

https://www.bokchoys.com/differential/pictures/bolt_03.jpg

https://www.bokchoys.com/differential/pictures/bolt_02.jpg

[Falco]

[smegballs]

Yeah hand-fitting it is gonna be a bit time consuming, it's one of those bastard jobs where you do just one file stroke too many and it's way too loose and you have to start again....

Make sure it's a Class 8.8 bolt at least and not one made of cheese

What year is the CG?

[Falco]

[smegballs]

Give it a go, worst it will do is shear.

I just suggested 8.8 cos it's pretty common and reasonably strong.

This looks like the replacement cap??

I picked the 2004 model as couldn't see 2005 on there.

https://www.cmsnl.com/honda-cg125es-2004-england_model2599/cap-30mm_90087mr1000/#.Vl0Hpb8addg

[smegballs]

UK vendor here

https://www.davidsilverspares.co.uk/parts/by-part-number/partnumber_90087MR1000/

I'm gonna be bored at work till 6am (security night shift) so shout if you have any questions.

[mentalboy]

[MCN]

The plug and case have been gubbed by a gear lever in a previous life. That is probably a new/another lever on there as it is typical for the lever to be shoved into the cover when the bike is sent down the road.

There may be some damage to the plug hole thread due to this. The plug or case or both threads may have been twisted. That can make removal difficult. If it was removed later and screwed into damaged threads then the problem will have been exacerbated.

If you can apply some heat to the cover without transferring too much to the plug it may slacken off.

This will be handy

The tool can be used creatively in the kitchen.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[Suntan Sid]

If you can source a new part and you're prepared to butcher the old one, get a peg spanner of the correct size, (LH in picture below), drill two holes, job done!
If you've got a grinder you'll probably have one anyway.
Alternatively make one out of some flat bar and two M5 bolts, that's worked for me in the past!
Alternatively, drill two holes, screw in 2, self tapping bolts, lever round with a large screwdriver!

https://thumbs3.ebaystatic.com/d/l225/m/m2e1iN4ZHkyo3k9cMz_Hj1w.jpg
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"Everybody needs money, that's why they call it money!"

[Robby]

They always jam up when someone does them up too tight. An impact driver should free it off.

If you break it, a replacement crankcase cover is only about 30 quid on ebay.

[stirlinggaz]

hi,
beats me why anyone still uses "normal" allen keys.
after I ruined a wheel, trying to get threadlocked bolts (made of cheese) out of a brake disc (iirc) i chucked all mine in a box in a corner of the shed (where they still are)

I then bought a set of hex/torx bits that fit into a 10mm socket & a set of t-shaped allen & torx keys.

never rounded off a bolt since nor failed to get a bolt out. (though I've had to hammer in a torx bit a few times due to spack handed po's)

TL/DR? buy some decent tools.


cheers,
GAZ

[Falco]

Thanks for the replies, Lots of great advice!

It looks like I have a lot of options to work through (though I will be trying to save the case, a new case is pretty far down the list of things I want to replace unless the thread itself is damaged).

If all else fails and I have to remove the whole case (thanks mentalboy, that never even occurred to me), is there anything I need to watch out for? I assume there is a gasket of some sort which will need to be kept clean and intact. Are there spacers that will drop out when removed or something else that will fall out/break?

I'll start going through the suggested methods and let you know how I get on.

Thanks again everyone.

[MCN]

[Islander]

[mentalboy]

[stirlinggaz]

[MCN]