Running on 2 cylinders help!!

[02GF74]

I wasn't blaming you but trying to point out it is not the internet or browser that caused it - the browser simply renders what was typed or copied in the text.

 

[Fire-medic]

Well you should blame me, because I did it! For some reason, the correction didn't register when I made it, until I erased the entire email address, and re-typed it. The address is correct, there is no hidden 'incorrect' email address.

 

[02GF74]

If you had your carbs off,they need to be adjusted and syncronized.I just had the same issue.

Have to say I'm sceptical, if fuel is poured /squirted into the carbs, effectively by passing them and having no effect, then that surely can be due to no spark?

BTW when I said replace plugs, I meant fit 2 new unused ones on the non-running cylinders, sometimes they can get fouled a d then won't spark.

What do those 2 plugs look like?
Maybe worth cleaning them and checking the gap is correct.

 

[BRAD180]

No critters in exhaust the left bank carbs the little holes are at the 12 ocklock position and right bank carbs the 6 ocklock position

Looking at your pic there,i notice the choke plunger is closed on #2 but open on #1 and #4,can't see #3,something going on there.

 

[tvmax]

I see my error, weird. Went to one2dnax even tho i clicked link provided

Where do you live? Maybe someone is close and much easier to diagnose.

 

[Fire-medic]

Looking at your pic there,i notice the choke plunger is closed on #2 but open on #1 and #4,can't see #3,something going on there.

A good point of view! Check the difference in the enrichment piston shafts, definitely out of adjustment, whoever butchered the rebuild on these probably neglected to re-tighten the rod set-screw for the forked follower which grabs the piston shaft. I rarely remove those rods when I soak a set of carbs, I just back-off the hex nut w/the rubber seal boot so the piston is loose in the bore, and when they come out of the soak, I use WD40 or CRC 5-56, then make sure they move smoothly before re-tightening the shaft nut.

Look at the difference between them. What-about the one we cannot view, how does that look?

 

[87buickT]

Update, sorry for delay I pulled carbs off again ensure pilot jets were clear got 3 cylinders now won’t run with choke off but before I jumped back in here I did notice my non firing cylinder the set screw that your referring to is missing and if I manually pull out the piston it does pull itself back in and it appears I gain all my cylinders, kinda hard to do by myself Is their a certain setting they need to be at? Because it appears they all go all the way back in

 

[02GF74]

This set up is common on mikuni carbs, it is probably M4 or M5 screw and locks the lever to the shaft, the shaft may even be grooved.

I don't think adjustment needs to be precise, the important thing is when the choke is off, the piston is fully in with a bit a clearances - take a look at the others and set it the same.

 

[87buickT]

I would assume theirs no need for bushings on the shaft in between the forks?

 

[dannymax]

It's an M5 thread, the screw tip will seat in a recess in the rod. Will seat better if you round off the end to the screw. A short socket cap Allen head works ok.
No need for a bushing but there should be one between the choke rod and carb body.

 

[02GF74]

So happens that my carbs are off.
Photos below show choke on (fuel enrichment on) and off, I notice that the piston on the right had not fully returned, a job or tomorrow to sort out.

 

[87buickT]

Put set screw in only way I can get all 4 is if I slightly pull plunger out on that front left carb, bike seems a little rough running tho. Maybe a carb sync issue or air fuel mixture issue? The left rear carb I can see fuel flowing at idle past needle all other 3 are fine any ideas?

 

[Fire-medic]

Try to make all four enrichment fingers open and close to the same positions. Pretty-sure there are flats on that rod on either pair of carbs, for the set-screws. More-like indents, where some worker started a hole with a drill bit on the rod, leaving an indentation for the set screw. You can carefully-bend the fingers on the lifter for the enrichment plunger, to synch the pistons, so they all lift the same amount, at the same time. You don't need to remove the rod to remove the pistons, if you want to check them for oxidation, they're brass so they do not rust. Use I think a 10mm open-end wrench to remove the gland nut securing the enrichment piston into the casting. Clean/inspect for any deposits or oxidation, which would inhibit their movement. The piston can be removed once the gland nut is backed-out/off. I use CRC 5-56 or WD-40 to lubricate the pistons for re-assembly.

 

[87buickT]

i removed the one, it was clear, and spent a little extra time with adjusting the fork to make it exact same, seemed to run better going to test drive it here in a bit and advise. Hey its atleast moving now alot better than when i first started

 

[02GF74]

Try to make all four enrichment fingers open and close to the same positions. Use I think a 10mm open-end wrench to remove the gland nut.

The screws are turned to a smaller diameter at the ends to locate in a hole in the rod.

Good tip about blending the fingers to synchronise,never occurred to me.

I noticed one side was pulled out more than the other, it didn't cause a problem but I unbent the linkage to fix that, after removing the small spring washer to release the linkage at one end.

It's 14mm to undo the brass nut for
the enrichment pistons.

 

[87buickT]

So runs great, kinda rough in my opinion but ive never driven one of these, hits on 4 but only when those pistons are pulled out ever so slightly. Seems to not like it when they are all the way in but maybe just needs some miles put on it, yesterday it wouldnt even run with choke fully off but today it does so maybe im just bein ultra picky

 

[87buickT]

Update....a year later now that I've gotten back to the bike, I had help from a member who was local to me last year, we synced the carbs the best we could but did find a vacuum leak on front right cylinder when we huffed it with propane. I installed new boots the other night and fingers crossed the issue is resolved. Will post update with results, pictures attached but when I pulled the boots off the manifold and I saw what you will see circled it was a eureka moment and I knew that was my issue along with dry rot cracks, only wished I had pulled and inspected some time ago.