Motorbike problems...new to welding!

[scs1980]

Hi All,

i have a motorbike, and have an engine mount bolt that snapped off, i tried to get it out with Left Handed Drill bits, and also some bolt extractors but no luck...

Currently stripping the aux parts off the bike to be able to then drop the engine, theory is IF i cannot get it out with better access ( really hope i can ), can i weld a nut onto it to give me something to back it out with?

I know the frame is cast aluminium and i assume the bolt is some form of steel, maybe stainless or coated in something, it was easy to drill with the Cobalt drill bits i have, i have never welded but have a MIG welder on the way, and have been doing plenty of research....

joined this forums to hopefully get any idea's or do's and don'ts, will post a pic or 2 up shortly

Thanks

Sam

 

[scs1980]

The bolt, crash bobbins normally insert from the left, and as you can see this bolt has "luckily" sheared off in a way that means i can drop the engine, if it had been part in the frame lug, would have been trickier...

 

[Robotstar5]

The heat of welding a nut on can help to "break" the corrosion etc. that's holding the bolt.

What bike is it?, lots of bikers in here

...and welcome to the forum.

 

[addjunkie]

Drop the engine, put your stud extractor in the bolt, and heat the casting with a blow torch. The ali will expland faster than the steel therefore hopefully cracking the thread off. Hopefully itll come out easily.

If that doesnt work, drill out going up in size in half mill increases, till it cuts the edge of the thread and itll come out then.

Some times also i use either a small chisel or dot punch and hammer then loose after heating.

 

[BrokenBiker]

the order i would do it would be, lots of heat on the casting, see if that free's it up, if not then weld a nut on, let it partially cool and then get as much leverage on it and slowly try and turn it out (dont bang it with something, the weld will probably break the bolt a bit further downa nd make life harder)..if that still doesnt work i would cut the nut off, centre punch it and drill half mm below size of the bolt core dia then jam something in there and twist it out after some more heat

 

[The_Yellow_Ardvark]

As you strip down, get lots of penetrating fluid in it.
Try gently warming the casting when applying the fluid it will allow it to creep into the joint.

Then when both sides are available......
See above.

 

[scs1980]

The heat of welding a nut on can help to "break" the corrosion etc. that's holding the bolt.

What bike is it?, lots of bikers in here

...and welcome to the forum.

Its a GSXR 750...K3....

Thanks for the input all, i shall get the engine out the bike the next week or so, and then look into it.....the welder i bought has arrived so i am off to read the manuals for that firstly!

 

[scs1980]

As you strip down, get lots of penetrating fluid in it.
Try gently warming the casting when applying the fluid it will allow it to creep into the joint.

Then when both sides are available......
See above.

Yep, this is my biggest next hurdle, already have the knackered engine bolt, and those of you that work on bikes will know how tricky exhaust headers can be to safely navigate, have snapped studs in the past, so don't want to have that issue here....but lots of penetrating fluid will be used and also lots of heat

 

[The_Yellow_Ardvark]

Nip them up a Gnats do da before undoing. It will give you a start on your wiggle room.

 

[scs1980]

For reference i have a MightMig 100, be Sealey, don't expect to be ready to use it till next weekend, need to get the rest of the bike stripped, have done a little more tonight, just the exhaust system and cooling system to go then its engine drop time.

 

[Pete.]

I would do that in situ. Offside mount has a sleeve with the bolt through it I think. Un-do the pinch bolt and remove the sleeve if it exits towards the outside. You'll have a fairly big hole to work though. Even if that doesn't allow enough room you don't need to drop the engine right out. Remove all but the lower rear engine bolt, slacken off the chain and rear wheel all the way forwards, you should be able to drop the engine down at the front enough to clear the frame lug without even touching the exhaust headers.

I know the frame is cast aluminium and i assume the bolt is some form of steel, maybe stainless or coated in something, it was easy to drill with the Cobalt drill bits i have, i have never welded but have a MIG welder on the way, and have been doing plenty of research....

The bolt is almost certainly a M10 x 1.25 grade 10.9. It's a fine thread so best get an original from Robinsons Foundry or something.

 

[Pete.]

Bolt is No19 here under cylinder head category, this is for the K4, they don't list the K3 parts online but if you phone them the lady really knows her Suzukis she will let you know if they are the same, which is very likely.

http://www.robinsonsfoundry.co.uk/s.../gsx-r/gsx-r750/k4-2004.htm#!gsxr750k4cylhead

 

[Robotstar5]

The bolt is almost certainly a M10 x 1.25 grade 10.9. It's a fine thread so best get an original from Robinsons Foundry or something.

+1 for Robinsons Foundry, used them for parts myself.

 

[scs1980]

I would do that in situ. Offside mount has a sleeve with the bolt through it I think. Un-do the pinch bolt and remove the sleeve if it exits towards the outside. You'll have a fairly big hole to work though. Even if that doesn't allow enough room you don't need to drop the engine right out. Remove all but the lower rear engine bolt, slacken off the chain and rear wheel all the way forwards, you should be able to drop the engine down at the front enough to clear the frame lug without even touching the exhaust headers.



The bolt is almost certainly a M10 x 1.25 grade 10.9. It's a fine thread so best get an original from Robinsons Foundry or something.

Hi Pete, so effectively pivot on the rear mounts, so the front can drop down a little to clear the lugs, then as you say, exhaust system can stay as it is...?

 

[Pete.]

Hi Pete, so effectively pivot on the rear mounts, so the front can drop down a little to clear the lugs, then as you say, exhaust system can stay as it is...?

Yes but you'll have to remove the back half of the exhaust at least.

 

[scs1980]

ok so i went to have a look, and it may not work, will add a pic later tmrw, its a full exhaust, headers and link pipe as one with just a end can screwed on with 4 bolts, so even with the exhaust hanger bolt removed near the rear set, i would not have any play maybe a cm, to pivot before it hits, will add a pic so this make sense....but not sure it is going to be possible, BUT at least IF i do have to get the pipes off i can still not fully drop the engine.....will add pics tmrw..

 

[scs1980]

So as promised, as you can see the exhaust system has 2 issues, with regards to the idea above, its a single system, i.e. no link pipe, so i cannot take the back off, and secondly, that means i doubt i will have more than a cm of movement with the engine pivoting on the rear bolts as the exhaust will catch the under-ending hanger.......

so will carry on with getting last few systems off i need before i can drop the engine, exhaust bolts are going to be the challenge...but whacking them with penetrating fluid at the moment...

Current state of the bike...