PO Damage/Missing VM Carb Parts

[Shaughn]

Hi All, This is my first question asking post, I think(hope) I searched enough before asking.

The backstory;

I bought a 1978 GS750E last weekend, 30K, clean-ish looking bike
started, ran, a bit of a stumble, was registered and driven about 1000 miles last year, fuel leak, newish tires, generic pods, somewhat beatup 4-1: picked up for $500. good deal I think

"Opportunities" I've found so far:
Removed gas tank and all painted parts for stripping and refinishing, mainly
because I don't care for the faded grey, exterior rust minimal.
Gas leak was @ petcock, new one ordered. Very light tank spot rust
but will etch, and coat.

Exhaust somewhat more beat up than I thought, and will need some sealing before I get going, may be replaced if the money lines up. Cheap
flanges @ header, no exhaust gaskets, and leaking.

Only 11.4v @ battery and falling. R/R fails stator paper checks, and
the stator does as well (60VAC/60VAC/24VAC). Magnet wire and Honda R/R to be ordered this week.

Oil Leak @ Valve Cover Gasket, near tacho cable, already has new valve cover gasket & new headgasket though, hmm.... Be interesting when I pop the cover to check the valve clearance

Oil is clean, removed stator, carbs this morning. Will rewind stator this week, and tore down carbs tonight, and hence the questions:

The Questions:

I followed Paul Musser's fine VM Carb Rebuild instructions, and some things
did not line up with my setup, but for the most part they did. (Namely the throttle stopper plate cannot be removed with #1 carb top on, and the mounting plate cannot be removed before the throttle shaft as the throttle shaft passes through the mounting plate) ( http://www.thegsresources.com/files/vm_carb_rebuild.pdf )

I found a one pilot air screw stripped (got it out, but will have to replace) and a couple of the slide needle housing screws (the ones in the slide) stripped (one set will need to be drilled out, yay).

The most troubling thing is that one of the pilot (fuel) screws was driven into the carb body and broken off. The tip is now wedged in the jet(port?) Any ideas on how to get this out? Its not a straight shot down the slide, so drilling does not seem possible, and drilling from the bottom blind will likely ruin the jet. I have it soaking now and hopefully that loosens it up.

On another carb body, the little tab that locates in the slot on the slide is gone, broken off. The slide seems no worse for the wear, but who knows? Anyone have any experience with this? Will it bind? Will this be a fatal failure?

Also, I am missing (according to Paul's pictures) A spring, two plastic washers, and a gasket at the top of all four jet needles. I'm afraid to ask, but do I need to replace these? I assume I will as the needle had slop, and presumably would not otherwise?

Lastly, none of my float needles has springs, and Paul makes reference to paying close attention to them (no picture though). Should the float needles have a spring?

I greatly appreciate any help offered.

Thanks!
Shaughn

Registered as 1977, Mfd: 9/77, PO claims its a 1978...
Engine: GS750-49349
Frame: GS750E-12753
Main Jets: 102
Jet Needles: 5F21-3
Bleeder (Pilot Jet): 15
Float Needle Seat :23
Slides: 1.5
Miles: 30,673
Intake: Generic Pods
Exhaust: Beat-up 4-1

[TheCafeKid]

Hi All, This is my first question asking post, I think(hope) I searched enough before asking.

The backstory;

I bought a 1978 GS750E last weekend, 30K, clean-ish looking bike
started, ran, a bit of a stumble, was registered and driven about 1000 miles last year, fuel leak, newish tires, generic pods, somewhat beatup 4-1: picked up for $500. good deal I think

"Opportunities" I've found so far:
Removed gas tank and all painted parts for stripping and refinishing, mainly
because I don't care for the faded grey, exterior rust minimal.
Gas leak was @ petcock, new one ordered. Very light tank spot rust
but will etch, and coat.

Exhaust somewhat more beat up than I thought, and will need some sealing before I get going, may be replaced if the money lines up. Cheap
flanges @ header, no exhaust gaskets, and leaking.

Only 11.4v @ battery and falling. R/R fails stator paper checks, and
the stator does as well (60VAC/60VAC/24VAC). Magnet wire and Honda R/R to be ordered this week.

Oil Leak @ Valve Cover Gasket, near tacho cable, already has new valve cover gasket & new headgasket though, hmm.... Be interesting when I pop the cover to check the valve clearance

Oil is clean, removed stator, carbs this morning. Will rewind stator this week, and tore down carbs tonight, and hence the questions:

The Questions:

I followed Paul Musser's fine VM Carb Rebuild instructions, and some things
did not line up with my setup, but for the most part they did. (Namely the throttle stopper plate cannot be removed with #1 carb top on, and the mounting plate cannot be removed before the throttle shaft as the throttle shaft passes through the mounting plate) ( http://www.thegsresources.com/files/vm_carb_rebuild.pdf )

I found a one pilot air screw stripped (got it out, but will have to replace) and a couple of the slide needle housing screws (the ones in the slide) stripped (one set will need to be drilled out, yay).

The most troubling thing is that one of the pilot (fuel) screws was driven into the carb body and broken off. The tip is now wedged in the jet(port?) Any ideas on how to get this out? Its not a straight shot down the slide, so drilling does not seem possible, and drilling from the bottom blind will likely ruin the jet. I have it soaking now and hopefully that loosens it up.

On another carb body, the little tab that locates in the slot on the slide is gone, broken off. The slide seems no worse for the wear, but who knows? Anyone have any experience with this? Will it bind? Will this be a fatal failure?

Also, I am missing (according to Paul's pictures) A spring, two plastic washers, and a gasket at the top of all four jet needles. I'm afraid to ask, but do I need to replace these? I assume I will as the needle had slop, and presumably would not otherwise?

Lastly, none of my float needles has springs, and Paul makes reference to paying close attention to them (no picture though). Should the float needles have a spring?

I greatly appreciate any help offered.

Thanks!
Shaughn

Registered as 1977, Mfd: 9/77, PO claims its a 1978...
Engine: GS750-49349
Frame: GS750E-12753
Main Jets: 102
Jet Needles: 5F21-3
Bleeder (Pilot Jet): 15
Float Needle Seat :23
Slides: 1.5
Miles: 30,673
Intake: Generic Pods
Exhaust: Beat-up 4-1

Ok...Bad news and good news. Bad news. You're not likely going to get the tip of that screw out of there. You might, but good luck Seriously.

Good news. You're not missing any parts. You have 1977 VM26SS model carbs. They did NOT include those parts. Also, your NEEDLE JET is a different model number, i believe it to be slightly larger, and your throttle cutaway size is 2.5 instead of 1.5. (although you say its 1.5, also OK) Your pilot jets are supposed to be larger as well, although, if not, do not freak out, it will still run just fine I think THOSE are supposed to be 22.5? But all the others have 15s in it. Its all good on that part. Which carb has the busted screw in it? I may have a spare body I would be willing to sell...You're going to need to upjet to get that thing to run right however, PM me and I will likely be able to give you a good base point to start from. I have the same bike, same carbs, and have the same 4into1/pods set up. The float needle SPRINGS are INSIDE the float needles. He mentions to pay close attention that they have roughly the same amount of spring to them. If one feels funky, ditch it and replace it. Actually, replace them all. You can buy sets from Z1, and for some silly reason, they come in packs of 6.

[Shaughn]

Ok...Bad news and good news. Bad news. You're not likely going to get the tip of that screw out of there. You might, but good luck Seriously.

Damn. Okay, I guess in my gut I knew that.

Good news. You're not missing any parts. You have 1977 VM26SS model carbs. They did NOT include those parts. Also, your NEEDLE JET is a different model number, i believe it to be slightly larger, and your throttle cutaway size is 2.5 instead of 1.5.

Great! I'm little unclear on what you mean in that my cutaway size is 2.5 instead of 1.5; You mean that's what it would have been stock, right? They are marked 1.5, and I'm making a blind assumption that that means they are 1.5s.

Which carb has the busted screw in it? I may have a spare body I would be willing to sell...You're going to need to upjet to get that thing to run right however, PM me and I will likely be able to give you a good base point to start from.

PM Sent, Thanks!

The float needle SPRINGS are INSIDE the float needles.

DUH! I remembered that from my XS750 as soon as you said it. (This is why 11:30PM may be a bad time to start tearing down parts for the first time)

Any thoughts on the missing slide nub? (Unfortunately its not on the same body with the smashed pilot screw)

Much Appreciated,

Shaughn

[Shaughn]

On another carb body, the little tab that locates in the slot on the slide is gone, broken off. The slide seems no worse for the wear, but who knows? Anyone have any experience with this? Will it bind? Will this be a fatal failure?

Bump.

So I've drilled out all the stripped screws, and I'm buying a carb body and pilot screw off of TCK (Thanks, again), so I think I'm on my way home.

I can't imagine that that missing tab in the slide bore is going to cause a problem as it is a loose fit to the slot on the slide regardless, but I would be more comfortable knowing that others ran without problems with it. I'd hate to be on the highway and have that slide get stuck WOT on me. Any thoughts?

Thanks,
Shaughn

[TheCafeKid]

Yeah you might get yourself in trouble with that. Because as you say, the the slides themselves are a semi loose fit in the bore, that tap basicly centers the slide in the up and down travel. If it were to get cockeyed going up or coming down, the needle may jam it to a stop, or the slide itself jam up on the bore, because of the way the actuator arms pull up in a radial fashion, rather than straight up. coming up its going to put a bit of a rolling torque on the slide. Might try, if you have the patience, rebuilding the tap with some JBweld or epoxy or something. measure the location of the rest, then put a dab or two of whatever in the one thats missing in that location, build it up a lil at a time, maybe break out a dremmel and sand it to shape. Its essentially nothing more than that anyway. OR, you could just buy that carb body off me. Number 3 was it?

[makenzie71]

without the tab your slide is free to rotate 360*, and they will.

[TheCafeKid]

without the tab your slide is free to rotate 360*, and they will.

Actually on THOSE carbs, it cant rotate 360. It cant rotate at all. The pivot arm is screwed into the slide at two points.

[makenzie71]

gotcha....

[Shaughn]

Two for the show...

Actually on THOSE carbs, it cant rotate 360. It cant rotate at all. The pivot arm is screwed into the slide at two points.

Yeah, It can rotate a little, maybe 5°, due to slop in those ball joints, but essentially it's static. The needle getting bent is what concerns me, however I recognize that this may be paranoia...

The jammed screw is in #3, the missing tab is in #4. Do you have that one as well? I wouldn't JB Weld it, as I can see that ending up a tasty little nugget for the piston to chew on. I might drill and slit the side and put a tab through, however, as that looks like that was how it was originally done.

So, it might be two carb bodies that I'd be buying off you. We never clarified method, paypal, etc. Should be a PM in your inbox asking that.

Thanks again for all you help.

Shaughn

[Shaughn]

Fleabay VM26's

Oh, and I was almost kicking myself for not picking up these kawa VM26's in addition as a backup. Would they have worked? I never confirmed, and the auction ended anyway

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&sspagename=STRK%3AMEWAX%3AIT&viewitem=&item=380039348847

Thank,
Shaughn

[Nessism]

The tip can be removed by using a long pointed punch and driving the tip backwards working from the inside the carb body. I did two carbs this way and the tip came out no problem.

Good luck.

[TheCafeKid]

Yeah, It can rotate a little, maybe 5°, due to slop in those ball joints, but essentially it's static. The needle getting bent is what concerns me, however I recognize that this may be paranoia...

The jammed screw is in #3, the missing tab is in #4. Do you have that one as well? I wouldn't JB Weld it, as I can see that ending up a tasty little nugget for the piston to chew on. I might drill and slit the side and put a tab through, however, as that looks like that was how it was originally done.

So, it might be two carb bodies that I'd be buying off you. We never clarified method, paypal, etc. Should be a PM in your inbox asking that.

Thanks again for all you help.

Shaughn

I dont have number 4 available. Its already been a donar for a buddies rack that had a broken screw tip in it. I do have number three available tho. It will be monday or tuesday before i could send it. Paypal the.godfather44@gmail.com. I'd say 12 for shipping, if its more than that i'll eat it. so 42 bucks and she'll be on her way to your door

[Shaughn]

What's for dinner? Boiled Carb Bodies

Update; spent all afternoon doing a thorough carb cleaning, these things were an absolute mess. (I had only disassembled them last time, and stopped due to the solid 1/32" of muck on everything.)

Apparently those locater tabs are plastic, not brass. They cleaned up and are transparent. There's just enough left over that I can't rotate the slide in the bore once its in, so I won't end up replacing the #4 body.

Also, when I was going through old threads, someone had mentioned something about boiling the carb bodies to clean them up. I thought it was odd at best at the time. But after several hours of scrubbing and getting them 95% clean, and after still having no joy getting the broken pilot screw tip out through solvents, picks, micro drills, and air pressure, I was open to 'odd' ideas. I finished the dip/scrub/clean on everything, and then dried and boiled the carb bodies, bowls, & tops for about two minutes at a steady boil. Cleaned all the remaining residue off, and when I took the warm #3 carb body, and went at it one last time with the pick, the broken tip popped right out! So, I'm good on all bodies now!

I've want to order four new pilot fuel screws because they all are a bit wonky, hopefully to arrive with the jets I ordered last night before the holiday weekend. Is the z1 rebuild kit really the only way to get them? I mean, its a good kit, but I feel like I'd be spending $80 instead of 8-16$..:-?




I should've posted BEFORE pics so you understand why I'm feel good about this, but here are the afters...




Oh, and I found that my one of my choke downspouts was cracked, but at this point I'm not going to do anything about it. Thoughts?

[Shaughn]

Sorry for the oversized pics last night, twas late.

So, no better source of the pilot fuel screws?
I called Z1, but got a minimally helpful "search for mixture on the site, that's all I got not in kits":-?

[TheCafeKid]

Im pretty sure BikeBandit and Babbitts sell the mixture screws seperately...might give them a shot.