Machine Shop needed - Carb Repair

[Kurlon]

I'm about ready to blow a virtual gasket... just sent my carb rack to Sudco for a rebuild... have conversation about the costs noting if I need carb bodies I'd be better off importing a new rack from Japan as the individual parts are stupid expensive... get bill for nearly the cost of carb rack from Japan with note that 'By the way, #1 carb body has stripped cap screw bosses.'

If you knew that, WHY DID YOU PROCEED WITH THE REBUILD?!

I'm NOT a happy camper right now. Sudco's suggestion is to talk to a machine shop to get the thread repaired, I don't recall there being enough material to support a helicoil/timesert but I suppose I'll find out now. Anyone got a recommendation for a shop to try and get my carb body repaired at? Carbs aren't due back until Friday so at this point I suspect I'm out for August.

[gamorg02]

if a machine shop is needed i'd recommend harrys but i see you're quite a bit away from them (northboro, ma). can you put a nut with loctite/lockwasher/nylonnut or similar on the back with a longer screw?

or helicoil?

[Kurlon]

It's not a through hole so the longer bolt/nut trick won't fly. (The bowls are already partially held on that way...)

[MarkMarine]

I would look at having a welder build up the area, then re-drill and tap. I'd offer to do it, but I'm a little rusty for fine work like that and I don't want to damage a rare carb body.

This is the reason I don't let other people work on my bike. I'd talk to the shop and see if they care at all about their reputation, the suggestion being they make it right.

[csmutty]

drill it out and use a split insert?

[Kurlon]

My concern with drilling is I don't recall there being much material to work with in the first place, although at this point it's not like I've got much to loose by trying I suppose. On the welding side, can you weld cast aluminum reliably?

I agree 100% on not letting others work on my stuff... got myself into a bind with wanting to get the carbs sorted by Round 4 and not having the parts or experience with the FCRs and was concerned that there were some setup / assembly issues from their past contributing to the random sticking throttle problem. I took the advice of an expert and sent them out rather than picking now to figure them out myself...

Lesson learned. This is why I'm ramping up to convert this thing to fuel injection, parts will be easier to source and after I'm done doing the conversion I'll know every inch of it start to finish.

[rg500]

Every casting welds differently. Better castings tend to weld better. I would bet it would work but would require the complete disassembly of the carb and you run the risk of it warping. It is a little hokey but have you thought about building it up with Jb weld and retapping it? It isn't structural or subjected to extreme temperature so it should be ok. Hard to give you real advice without seeing it.

[Kurlon]

It can't be that hokey an idea, Loctite and Permatex make a kit for exactly that purpose. Now I get to go stir crazy waiting to get them back before I can see and assess for myself... bah.

[Degsy]

Wirelessly posted

Jb weld would be fine. I would also put some non-hard gasket sealer on that bowl

[MarkMarine]

Or, if you need it to run for next round, how about firing a larger, coarser, sharper, screw into that soft AL casting. Then you can sort it out when you aren't pressed for time. it's not like you'll damage the threads, they are already forked.

But as far as welding a casting, the answer is "maybe"
I've welded up tabs on engine blocks and transmission casings (having oil come out of your weld bead as you're laying it sucks, but you wouldn't have that problem with a carb) and if your welder went slow and didn't let the rest of the body get too hot, it's probably do-able. You could always email Mikuni or Keihin and ask them what alloy they cast your specific carbs out of, if you know the alloy it's easy to find out if it's weldable.

[Degsy]

Im no welding expert, but Im pretty sure that you would royally screw that carb body up with that kind of heat.

It has a gasket, just use a self-tapper a littrle larger or JB weld.

[rg500]

I am with Degsy on this one. No reason to make a small problem bigger.

[gamorg02]

It can't be that hokey an idea, Loctite and Permatex make a kit for exactly that purpose. Now I get to go stir crazy waiting to get them back before I can see and assess for myself... bah.

i've heard of good results for this type of repair with that type of stuff now you guys mentioned it.

like this kinda thing?

http://www.loctiteproducts.com/p/mec...poxy-Putty.htm

[Kurlon]

More like: http://www.henkelna.com/product-sear...=8797876355073

http://www.youtube.com/watch?v=FqpStMLTE6E

[MarkMarine]

I'll agree, well I still think welding it *could* work and would be more "right" if done correctly, there is a lot less risk using that method, especially if this is basically non-structural.

[DaveZX6r]

First off I'd call up sudco and ream them the f out. Then I would try filling and retapping. I've done it with low strength stuff. They actually make metal filled putties for metal repairs two. I can't remember where the hell I found it though. Probably MSC, or McMaster etc. Good luck.

[Stromper]

Alumiweld propane filler etc

I would just tap the next bigger screw even if it english

[Kurlon]

First off I'd call up sudco and ream them the f out. Then I would try filling and retapping. I've done it with low strength stuff. They actually make metal filled putties for metal repairs two. I can't remember where the hell I found it though. Probably MSC, or McMaster etc. Good luck.

Looking over the whole thing now that I've had a sec to stew I can see why they did what they did. Bad communication on both our parts, I should have been clearer on what damage would make repairing pointless. Plus, reaming them out won't do me any good, they can't get carb bodies for these carbs any more. Again, learning experience.

In the mean time I've picked up a M4 x .7 Helicoil kit, can't find any of the epoxy based thread repair kits locally but my goal is to have that in hand as well for this weekend's repair attempt.

[DynoTune]

you are not going to weld that carb... you need to JB weld a stud on there if you can...

[Paul_E_D]

Cripes, for next weekend 3 screws and yamabond would probably hold it together...

JBweld and a retap would be my long term solution. and then don't fork with it.

[Mvalenti]

Alumiweld propane filler etc

I would just tap the next bigger screw even if it english

+1

[Kurlon]

Cripes, for next weekend 3 screws and yamabond would probably hold it together...

JBweld and a retap would be my long term solution. and then don't fork with it.

Not hacking it, sick of that. Spent the last two weekends hacking to keep gas in my tank...

[CBR929RE]

you are not going to weld that carb... you need to JB weld a stud on there if you can...

this sounds like the way to go. then you don't have to worry about drilling and tapping a new hole. easiest, quickest and probably best solution.

[nt650hawk]

done this a number of time. fill in the hole re-drill and tap it.

http://www.durafix.com/

[Kurlon]

[QUOTE=nt650hawk;1299508]done this a number of time. fill in the hole re-drill and tap it.

Cool, bring your rod and torch up to Maine this weekend...