Motorcycle cylinder head

[Screwdriver]

I need some advice regarding welding this:

It's a mates bike and I have said I'd have a go.

The plan is to weld it in situ. Just taking the cylinder head off will cost hundreds. I am planing to grind it back and clean the area thoroughly of course. Then hit it hard and fast with the TIG set to 100-150 amps (??), get some rod in as quickly as possible, then let it cool a bit, hit it again, repeat until filled.

I am assuming I couldn't fit the steel/stainless stud and weld over it?

So either drill and tap or fit a helicoil. It's not a structural item so I'm happy to have a go, it just needs to hold one of two studs. If it fails in service, the exhaust will not fall off. In any case, if it doesn't work, he's going to buy a new head for it. I have an old dead cylinder head to practice on.

Any tips?

Screwd.

 

[ronan]

Is that an exhaust stud boss screwdriver ? What bike is it ?

 

[Member 66061]

I would disconnect the ECU and obviously the battery.I dont know if its absolutely necessary to disconnect the ecu, but just for the benefit of doubt.
I took mine off my bike when i needed to get some alu welded in situ, but mine is easy to take off and i have rotten luck, so just thought better of leaving it connected.

 

[Tinbasherdan]

Should weld well enough for what it is. Be aware though that no matter how well you clean it, it isn't going to be clean enough and will be a bit "sticky" for want of a better word to weld

 

[zeppelin builder]

clean up the remains of the old boss with a carbide burr and earth localy ie on the plain portion of one of the other studs so you are not eathing across the head gasket it will be fine i usually use the ng6 filer wire as i find it a bit harder and better to drill and tap

 

[ronan]

You'd have to be chucking a fair bit of heat into it to get it to weld, it being such a big lump of aluminium.

 

[BrokenBiker]

double boost has a video on a very similar repair, his only advantage was the work piece was on a bench and he had a mill to put the hole back in with, might be worth a watch before tackling the job

 

[eSCHEn]

Richard. and hotrodder are the peeps who spring to mind. They love doing this kind of job They'll have some good info I'm sure.

 

[Screwdriver]

Thanks for the replies. It's a relatively recent Suzuki SV650. I'll check and see what rods I have. From the above recommendation for ng6, would there be a problem using "any old" aluminium wire?

It is a big lump of alloy so I assume big amps will at least get it going locally, then I just need to be careful not to allow too much heat to distort it. Unlikely while it's all bolted down and it's just a boss sticking out. I am more likely to melt it off I should expect!

I'll have a look for the doubleboost vid. He's on my subscribed list but there's too much cookery on that channel at the moment. If I want to cook I'll visit Jamie Oliver!

 

[BrokenBiker]

i fear it may be in one of the SNNC vids so there are only about 200 videos to look through haha

 

[Brad93]

I would imagine thats going to need nearer 200 amps it being a large piece, unless you preheat it.

 

[doubleboost]

 

[johnik]

You say it,s not structral so,Is it not posible to drill the hole deeper and thread it then "glue" the missing piece back on or re-make it with some chemical metal ?

 

[Tinbasherdan]

We used to weld them with 4043 and never got one back. If you can put a stud in, more the better, should at worst only have to run a tap down it afterwards. As said it's a large lump so a bit of pre heating wouldn't go amiss, and I'd be throwing 200a at it, you can always back off on the pedal

 

[rikrobson]

You could try the hts 2000 Ali brazing rods.

 

[roofman]

You say it,s not structral so,Is it not posible to drill the hole deeper and thread it then "glue" the missing piece back on or re-make it with some chemical metal ?

The main problem being an SV650 is going to deep might enter a water jacket..you dont get much meat on water cooled motors from Japan

 

[Robotstar5]

Thanks for the replies. It's a relatively recent Suzuki SV650. I'll check and see what rods I have. From the above recommendation for ng6, would there be a problem using "any old" aluminium wire?

Got the same lump in my DL650, note to self, do not attempt to remove exhaust

 

[Screwdriver]

Brilliant thanks. That's full of really useful information. Nice one!

You say it,s not structral so,Is it not posible to drill the hole deeper and thread it then "glue" the missing piece back on or re-make it with some chemical metal ?

Glue? Err. No. You should be posting on glue-bodgers.co.uk

In all seriousness, modern epoxy/chemical metals are brilliant but I wouldn't trust one on an exhaust port.

We used to weld them with 4043 and never got one back. If you can put a stud in, more the better, should at worst only have to run a tap down it afterwards. As said it's a large lump so a bit of pre heating wouldn't go amiss, and I'd be throwing 200a at it, you can always back off on the pedal

Ok I have 250 amps to play with on my old KEMPPI and yes it does have a pedal. Are you saying it would be better to put a stud in place while welding?

I am a lot more confident I can do this having seen doubleboosts vid. Maybe I should try one of his recipes, are they really edible?

S.

 

[RichardM]

I welded an old KZ1000 head up on the exhaust studs with 150A (air cooled and off the engine. If you want to re-drill and tap for the stud make a jig up before welding using the other stud and locating in the exhaust port , bolting to the other stud and a drill guide made up for the one you want to re-drill after welding it up. Saves the guesswork.

 

[Pete.]

Richard. and hotrodder are the peeps who spring to mind. They love doing this kind of job They'll have some good info I'm sure.

Years ago Hotrodder welded up a clutch release arm housing for my stepson's motocrosser. The chain had snapped and wiped out the casing but after the repair it worked as good as new.