VM26; correct needle to arm assembly

[jibledso]

Well, I think I?ve racked my brain enough between the forum, Bikecliff, and schematics trying to figure out the correct steps to putting the slide to arm assembly together. I took them a part over a year ago and I?m pretty sure I?ve put them back together incorrectly even though the bike runs and screams to 8,000.

Right now I have needle, clip, plate inside the slide. Inside the arm is spring, small tee then threaded bolt that is used to adjust the slide, then large washer, locking washer, then nut.

I never recall seeing any plastic looking washers around the needle clip, and I have to accept someone else had been inside before and maybe didn?t put it back together correctly. When I bought the bike it never had a great idle, i was constantly holding the throttle at stop lights.

I searched the forum and found some information and I think it?s needle, spring, washer, clip, larger washer, plate. Then inside the arm is spring, small tee, adjuster bolt, washer, locking clip, nut.

The spring inside the arm is stiffer than the needle spring correct?

These schematics didnt help help a lot because they seem to be showing different carbs but then I thought they are just showing different information.

In this schematic it showes what?s inside the arm but not the slide except the needle and clip, just like my bike.

 

[jibledso]

The second schematic numbers the inside of the slide and not the arm. Are both correct? Can anyone point me in the right direction please?

Btw, after having the bike on its center stand, running, and warming up for at least 4 mins I tried to pull it out of the garage for a quick ride, but once I pushed it to the door fluel began pouring from everywhere, very strange.

 

[standswithabeer]

will need model/year of your bike, because it appears that some carbs have the plastic washers while others don't. here's the schematic for my 79 750L showing plastic washers that were present { #26 }

never took the spring out of the arm, but i can tell you the needle spring is delicate.

https://www.partsfish.com/oemparts/a/suz/50d40018f8700230d8b4e1f4/carburetor

 

[jibledso]

I have a 77? GS750, or at least that?s what the title says, some say twin disc are not possible on a 77? but that?s what I have, and it?s a European bike with kph not miles.

 

[jibledso]

Maybe when I go to the garage tomorrow I can drum up some small washers for my needle, and I?m pretty sure I have some robust springs for the arm, and the springs in the arm now belong with the needle.

 

[standswithabeer]

your bike might be titled incorrectly, you can double-check model year based on frame VIN here:

http://www.ozebook.com/compendium/suzi/engine-nos/page2.gif

the numbers in the columns reflect the beginning VIN/engine number for that model year. my 79 gs750LN has a frame vin of 705891, early in the production.

 

[jibledso]

Well, my engine # is 26493 same as the number on the frame.

Frame # is 13678

couldnt find the number in your list


Also it says GS750D on the tag

i need to look at the title again, maybe I’m going off what the previous owner told me.

 

[jibledso]

I got back into the carbs

They never had the plate #27 on your schematic, plus there are no washers before or after the needle clip.



I guess whoever redone the carbs was like ‘I don’t need these’

What’s funny is the bike ran what I thought was quite good for a 40 year old bike but there was always a hesitation off idle plus it never idled that well, when it got warm it would drop off a lot.

 

[jibledso]

I?m pretty sure these are the springs that go in the arm, they?re pretty stiff unlike the needle spring.

 

[jibledso]

Just looked at partssweden here and low and behold they are out of them, must be the same problem the last guy had

I think my only hope here in Sweden is a guy in Karlstad who has the old Suzuki parts market cornered, but you have to call and order the old fashion way.

 

[Jhurt]

Just ran through this research on my bike few months ago. This thread may explain why you see different designs, I currently have both on my bench. Photos included!

https://www.thegsresources.com/_for...2-Carb-question-for-Mikuni-experts&highlight=

Basically you need to identify exactly which iteration of the VM26 you have then look for the appropriate schematic.

 

[standswithabeer]

very interesting jhurt!
-- the slide pic posted by jibledso doesn't show a recessed area for a needle spring
-- your pic showing the 78 vs the 77 slides shows no spring, a longer arm, and no plastic washer for the 77
-- it seems to me that adding a spring under the needle in a slide without the recess would cause a running issue.
-- your 77 slide pic matches what jibledso has currently.
-- it seems he has what is intended

 

[Guest]

I find info extremely useful. Having rebuilt my '78 GS750E's carbs just last month, I began to worry what other POs did to the bike.
For instance: I found carb 4's choke plunger set up with different springs (yes, plural as in '3' vs. '1') from the others. Asking around the GSR confirmed it was a hack most likely due to a lost factory install. A visit to fleabay got me the correct OEM spring w/spare plunger & now all's consistent across the rail Don't ask what I found under the intake tubes!!

Now knowing the VM26 changed with the '78 model year helped
rule out any 'mix & match' bundling amonst the bunch (all 4 carbs had identical slide constructions proper to the model year).

Thanks for sharing!! Live & learn as they say

 

[jibledso]

Yeah, after looking at your pictures I have a set of 77? carbs. That?s a relief, I thought I was going to have to spend more money, thanks a bunch for the info!

 

[Guest]

And to think, all I ever thought they changed on the VM26 design was the choke linkage!

 

[jibledso]

Has anyone heard of the spring in the arm connected to the slide wearing out?

my slides barely come up enough to meet the standard for the bottom of slide to carb body clearance.

my idle screw is turned in all the way and it does idle correctly but I have what I think is a valve guide seal problem.

but yeah, I wonder if those flimsy springs are working well enough. The 78? and later design looks like a better design.