Carb question

So last night while cleaning my carbs for the 4th time I dropped them . Everything looked ok until I noticed one of the posts for the float was broken :x . My question is, are there any other carbs that are compatible with my bike (a little modding is ok)? Or should I try and find the same ones? I have a 1982 xs400 maxim.

Thanks

 

I have no personal experience, but someone else on a different Yammie forum (SR250) was going to attempt repairing their float post using gas tank repair epoxy. You could give it a try too.

 

If you can't find a replacement Carb Body, ... you need to Fabricate.

Using suitable Precision Tools:
Remove the Broken Float Pillar
Drill a Hole centered on the Undamaged Pillar

Tap Threads on the Hole with a Bottom Tap
Cut Matching Threads on a Brass Rod.
Drill a Pivot Hole in the Rod

Machine material from the Rod to Mount the Float.
++>>Correct the Geometry of the Float with Miniature Flat Washers on the Hinge Pin acting as Thrust Washers to keep the FLOAT aligned between the two Pillars as needed.

 

do you have ANY idea what your talking ABOUT ?

 

pictures would be nice, but i would vote for suitable epoxy. obviously you need to use as little as possible because things are tight in there when the bowl goes on, but if you can get the piece to stick in its original place pretty well, you should be back on track.

or......

you should stick weld it.

 

You need to be careful driving out pins adequately supporting the legs, and remember some Mikunis only fit one way. We've repaired them on occasion, usually tig welding and a little die grinder for cleanup.

 

I did a quick search and it doesn't look like any other bikes use the same carbs. So your best bet is to look for a new carb(s) or try fixing the one you have. If you end up looking for new carbs keep your eye on ebay or look on craigslist. If you didn't know you can do a nationwide search on craiglook.com . Good luck!

 

You can pay to have it Laser Welded.
You need the broken-off part.

You send it in an a Robot Welder fixes it.
Minimum charge: $80,00

For $80.00 you ought to be able to fine a set of decent Carbs and Clean them.
But, if you can't, ... and you're behind the 8-Ball.

Send them in and these guys will fix you right up:

http://www.motorcyclecarbs.com/_P16629.cfm

 

wow, thanks for all the advice. I'll try the gas tank epoxy first. I called around and found a set for $100. I figure trying the epoxy wouldn't hurt and if need be, I know where I can get a replacement. I'll probably work on it in the next couple days and keep you all posted. Thanks again.

 

I've repaired two float pillars with JBWeld over the years. One broke off while driving out the float pin improperly supported, one was rotted off from corrosion!!

The broken was was easy - just put the two halves together and slathered with JBWeld around the outer area. Used a tiny length of bailing wire as a 'splint'. Done.

The build-up was just that - slowly built up layer after layer. Shaped with dremel and file. Drilled a hole. Done.

Both worked fine, and, AFAIK, are STILL working!

Good luck!

Kirk

 

Ok, so I bought some fuel tank repair epoxy and stuck the post back on. It's solid and holding steady. Just waiting for a new choke plunger and O-rings for my pilot screws. Figured out that, yes, my mixture was super lean (for those who saw my other post) all because of dead O-rings. I'll get the parts Friday and go from there.

 

"Stuck the Post back-on", ... with what???

 

Looks like he epoxied it back on.

MN

 

Yeah, I used fuel tank repair epoxy to stick the post back on.

 

I haven't heard too many success stories from people who broke-off a Float Hinge Pillar and used an Epoxy or Adhesive that did the trick.

I admire good-old-fashioned American Ingenuity when it comes to solving difficult problems and dilemmas such as a Broken Float Hinge Post.

Here's another solution which "Saves" the Carb without removing and replacing the Broken Pillar with a Machined Piece, having the Broken-off piece re-attached with Laser welding, or using anything in the "Adhesive" realm that might fail.

Have a look at this repair and appreciate the thought that went into saving the day with engineering.

(From the XS-11 Forums)

http://www.xs11.com/forum/showthread.php?t=27137

 

That is interesting as I had seen on other posts that JB Weld will eventually dissolve in gas (whereas the epoxy specifically made for gas tank repair didn't). Great stuff, but has its limitations?

 

So long as our Member with the Broken Float gets it fixed, ... right. OK.

I hate to have somebody go through any process thinking they've got it done; and the thing only last a day of so.

That's a bummer.

 

Rick, thanks for the previous post with the link. Very informative and quite creative. I might try that if this epoxy fails (as long as the carbs are still salvagable).
From what I've seen so far the epoxy works well. I epoxied two pieces of aluminum together the same day as the carbs and put them in a bowl full of gas. Still together and very firmly I might add, so I'm pretty optimistic. I'll keep up on the posts as my project continues.

 

ok, so I put the carbs back on and the repair is holding strong (so far). Still having issues though. I synced the carbs but whenever I give it more throttle the engine hesitates and won't go above ~1300 rpm still. Tried messing with the pilot screws, but honestly not sure what I'm doing. Should I close the screws to start, then slowly open then back up? Also noticed the left side of the engine is heating up faster than the right (mufflers too, go figure). Have spark on both sides.

Thanks.

PS-first bike plus first mechanical project, sorry for possible obvious questions.

 

To achieve higher RPM's:

The Throttles must Open
The Diaphragm Piston must rise.
Main Fuel Jet supplied Fuel must enter the Intake Stream.

Common problems for No Engine Speed:

Main NOZZLE (Emulsion Tubes) Clogged
Main JETS Clogged
ALL Float Height and related.
Stuck Diaphragm Pistons.

Fuel Delivery -- Petcock -to- Dispersion: Troubleshoot.

 

So the repair is great. Rick, went through you list. Cleaned main nozzle (wasn't clogged, but figured I would clean it anyway), all passageways and jets are clean and clear, diaphragm pistons smooth and clear (goes clunk), and not pinhole in the diaphragm itself. Started up, idles great, loses power at 1300rpm again. Listened real closely, sounded like it was completely losing spark when it hits 1300rpm. Checked spark, indeed it does. At 130rpm, no spark on right side. Back to idle spark is back and idles like a champ. Could this indicate a bad coil, plug wires, or worse...TCI?

 

Probably TCI.

 

Man, hoped it wasn't that. Thanks iwingameover. I read about "repairing" a TCI by soldering a point or two on the PCB, but I'm not sure which points and, can't remember where I saw the site. Any ideas? Thanks

 

PM Robert. He has a refesh service. I'm sure he can point you in the right direction.

Still probably want to test out all the other components though just to be sure.

 

Will do. At this point I'm thinking of starting again from square one. Been getting a lot of great feedback and info, but I feel like I'm missing something...or didn't check something correctly. Thanks again and I'll give an update as soon as I figure something out.

 

I would do a TEST.

Start the Bike.
While the Bike is running; attach the Leads of a Battery Charger to the Battery.
Set the Charger to Manual.
With the Current from the Charger supplementing the Bikes Charging System; see if the Engine will accelerate above 1,300 rpm's.

If it does, ...
Attach the Leads of a VoltMeter to the Battery and observe the Voltage at the Battery.
Disconnect the Charger.
Observe Voltage.
Rapid fall-off indicates Charging Fault or Battery unable to provide Amps to sustain energy demands.

Charging Volts: 11.5 ~ 12V @ Idle / 12V > rising as rpm's added. 14.2~14.5V at 1850 -- holding as rpm's increase.

You problem may be related to Insufficient Voltage being made to run the Bike properly.

 

Thanks Rick! I'll try that out first. Probably won't get to it for a couple days, but I'll post when I do.

 

If you bring-in a charged-up battery to AutoZone, ... they can test it and tell you how many Amps it's putting-out.

 

got lucky and managed to get time to check the battery tonight. Started the bike, idled, attached battery charger on manual. Tried to throttle, same thing, spits, pulses, this time backfire. Right side still losing spark past 1300rpm. Battery voltage start at 12v, with attached to battery at idle 14.35v. Throttle is 14.58v. No luck this time. Any other ideas? Thanks for the help.

 

Swap the two "Plug-in's" for those two Coils where they Plug into the Wiring Harness.

IF, ... the "Break-down" shifts, ... and the LEFT side becomes the errant Coil, ... the problem is -- the COIL.

IF, ... there's no difference in behavior, ... you have to suspect the problem to be elsewhere. Ignitor.

You could also uses a KNOWN-to-be-Good Ignitor and save time Troubleshooting a problem that's at the Box.

 

Just tried swapping the coils, still right side. Just to double check, the ignitor is the TCI box? Too many names and abbreviations floating around to keep straight.

 

Yes the ignitor is the TCI box.

 

If you havent torn it apart yet try using the choke and see it it will go past 1300 rpm

 

@waldo - Yeah, tried using the choke, but it's the same problem.

@iwingameover - Thanks for the clarification.

Plan now is to disassemble the whole bike, clean'er up, paint, put back together and then look into a new TCI or repair the old one. I might be getting another TCI for free to test with. I know it doesn't work, but I can't use it to test the TCI repair thread I found. I'll post again when I have some progress to report.

Thanks for everything guys/gals.