rebuilding vm24 with acc pump for dummies

I'll pretend I'm the dummy. There's only about 100 parts times 4, so what could go wrong, right? 

So I've got them out, and will start pecking away to take them apart tonight. I'm in no hurry, probably be a few weeks to finish. I'm just going to assume I should separate them all and then go through every pore and crevice, so unless someone warns me otherwise I will commence the carnage. I will only take apart one at a time. I will wait till I eviscerate them to decide what I need to order, but the plan is to replace all rubber and keep and clean all metal (especially jets) unless obviously bad. And in the meantime I will make offerings to the gods in hopes that some new air ducts drop into my lap before I'm finished. If they don't, I will either get air correctors or possibly use an older airbox or modify mine to take older air ducts by filling the holes and recutting them.  

I've got the FSM and there's a video showing the rebuild of these, although he conveniently bypasses all talk of the acc pump.  

I've got O-rings, both pump diaphragms, and fuel Tee's. 

Use an impact on the cross point screws holding the carbs to the joining bar.  I don't usually take the slide assembly apart, although you may want to do at least one to check the needle clip position.

The bodies are zinc, and like to turn dark if you leave them in an ultra sonic or in carb dip for very long.  Be sure to verify passages are open using carb spray, then blow them out with compressed air.

This tutorial may help.  

gsarchive.bwringer.com/bikecliff/images/vm_carb_rebuild.pdf

Ed's tutorial allowed me to overcome fear and dive in to my VM28's, turns out they're not that complicated. (But just to be sure I took photos and left one together while doing the other three).  Done two more sets since.  As he says, make sure ALL passages are clear, especially the choke and tiny pilot ones.  

Didn't take long to find a problem. Seems to be part of the accelerator pump system on #2 that is missing. Hard to find a good diagram of that part. I only see "pump cover"  which this is not.  




 

82KZ305Belt wrote:

Didn't take long to find a problem. Seems to be part of the accelerator pump system on #2 that is missing. Hard to find a good diagram of that part. I only see "pump cover"  which this is not.  

 

What is the issue?

That little cover on #2 held on by 3 screws that shows in your pic posted the other day is missing in mine. Your pic below for comparison

Some were built without that part according to year and spec. If you can post a better picture of the triangular section we should be able to say.

Yes Kevski, some of those pumper VM's had the triangle looking cover, some didn't. I believe though, all the KZ650's had them. Same as the KZ1000 VM26 but negated on the 28mm pumpers. Just so happen to have a set of those 26's i'm doing so therefore...sharing pertinent info. The VM 650's should be super similar. That sensor was implemented to keep one from sitting in the garage whacking on the throttle, squirting fuel, while not running. 305 if you can see light thru that Big hole into the float then YES, you're missing the diaphragm/spring and cover. I watched that video...interesting. When one says, and i quote, (think they call these pilot jets), ya know the you're dealing with someone that probably knows less then You, ha. Good Lord if i wasn't soo lazy and social media incompetent i could get rich making REAL videos with real world info that was skipped in all the manuals! Anyway here are some photos to help, if they do. Also take note of what ED mentioned!! The pestilence and miss-use of those ultrasonic cleaners abounds! The last two sets i've done had that abuse and soo fugly, just no resolve but to strip them down and blast off the discoloration. Last photo is a plate and gasket i made to keep media out of the tiny relief brass jet you see in the second photo.          

1981 kz650-csr. the triangular vacuum sensor was deleted at the factory. so nothing is missing. and obviously that diaphragm in the k&L AP kit isn't needed.  fyi. the fuel tee o-rings aren't available anywhere that I can find. closest size I've found (at z1Ent for example) are 2.0mm x 7.0mm but don't fit. the csr o-rings are fat.

Good to know H1, i haven't seen a 650 in years. I was going to say if that cover wasn't on there it would of been spilling fuel all over!!

years ago. I thought something was missing and had no idea what else might go there, so I got a replacement cover at the salvage yard. ha ha.

As mentioned in the other thread discussing these carbs, some model VM's have the "vacuum" valve, and others don't.  Most don't.  And that's a good thing, because they are problematic.

NOTE: this set of 650 carbs is on ebay.  See how this passage is not drilled.  That indicates that the set does not use the vacuum valve.