Can't sync the carbs...

[Fire-medic]

My Glaswegian friend is correct on the drill-bit. No drilling involved, you're using it as a reference spacer, to gap the (we in the Colonies call them) butterflies all the same. That's the 'bench-set.' Then you do the engine running adjustment as described in the Service Manual.

Do you have any baling wire? Just cut a couple pieces maybe 3" long, stick 'em into the butterfly gap, and tighten things up to just touch the wire thickness. Do the same for the other pair of butterflies. The screws should NOT be 'coil-bound,' that is, coils touching so-that you can no-longer screw in the slot head screw for that coil spring.

Whatever you have which is thin in the way of wire is what you need, sized the same thickness, of-course. Maybe a pair of m'lady's sewing needles? A couple lengths of 22 ga. solid-core wire, stripped of insulation? If you've ever set a pair of ignition points, you should be familiar with the tension, setting tappets is somewhat similar, the tension on the feeler gauges should be enough to create a bit of drag when you try to remove the feeler gauge, but not-enough to make it 'sticky' to remove. In other words, you're taking-up the slack.

http://vmoa.net/VMX12-Service-Manual01.pdf

 

[Zenuwlijer]

spacer

That's what I thought. Ok.

 

[Screwloose]

Do you mean I use the "behind of the drill" as a gauge? If so, mine are to thick for that use.

Yes that's what I meant.

Adjust the tickover screw to show a large gap. Can you get a drill bit shank in now?

 

[Screwloose]

That's what I thought. Ok.

Okay mate, I see the cavalry has arrived with bugle blazing at charge

It is just a round spacer, but anything does that does not mark your carbs or butterflies.

I'll get back to my Steve Stevens guitar practice then and hand you over. You are nearly there.

 

[Zenuwlijer]

I've finally found a "sweet spot" where none of the springs are compressed.

Used a .016 feeler gauge.

 

[Zenuwlijer]

Don't know the correct term for them, but the Slide covers look really good. Where'd you get them?
Thank You
Phil

You can get them over here, these are the new and improved version.

 

[Parminio]

Just for giggles, remember what this guy said:

This is a simple check. But I'm a simple guy. Anyway when I was syncing mine, I had the same problem. So I switch the hoses around to see if the problem were the Carbs or the Gauges. For me it it was the gauges. I found a pin hole in one hose and another had to much of a bend. I don't know as much as you guys, but sometimes it's just a simple fix. My 2 cents worth....

If you hook it all back up and it still looks the same, swop the hoses around just to make sure it's not a gauge problem.

 

[Mr. Max]

How about valve clearances? Won’t leaking 1 & 2 intake valves cause something like this?

 

[Zenuwlijer]

Just for giggles, remember what this guy said:



If you hook it all back up and it still looks the same, swop the hoses around just to make sure it's not a gauge problem.

I think it's gotta be alright now, because the carb valves are all set as they should now.

That being said... I'd swap the hoses in a heartbeat.

 

[Screwloose]

How about valve clearances? Won’t leaking 1 & 2 intake valves cause something like this?

Yes; no point putting work into a product if the air flow would be out at the valves clearances. I would have done them before the carbs.

But the carbs were the part/assembly that was changed in some way and under question, and some of the guys spotted anomalies in the set up, so headed there first. Hopefully it will all be okay now.

 

[dannymax]

Another method of bench setting the sync is, place a trouble light under the carbs...adjust the openings so the wedge of light between the throttle plate and carb throat is equal on all carbs.

 

[Screwloose]

I think it's gotta be alright now, because the carb valves are all set as they should now.

That being said... I'd swap the hoses in a heartbeat.

I'll assume you have got as far as our Miamian/Floridian buddy's input above!

If you do not mind a couple of points for later, as it sounds like you are now ready for action.

You have synchronised the flaps; this is what your Carbtune Synchroniser was trying to do, but does this with the engine running to accommodate all the anomalies with variations at each carb and cylinder with slightly different valve clearances etc (Mr Max above). So there was little point doing this flap set-up to near perfection on the bench as it changes slightly whilst running, but accuracy does help.

Build everything up including air filter, all clamps tight and so on. When you start the engine (probably on choke) be prepared to adjust the idle screw fairly quickly and get a near setting (rpm in the manual). Get heat in the engine and shut off the choke, and set the idle screw again to a nearness. Be prepared to be jumping between Carbtune Sychroniser and idle screw during running set-up.

You should see the Carbtune gauges showing within a couple of main divisions of each other, and it may already be within spec, but I like to fiddle around and get it very even. Go to the dreaded carb adjustment screws and when you do this adjustment do not lean on the screw but turn it only, and when I say turn I mean from say from 3 O'clock to 4'Oclock max, this will mean when you blip the throttle slightly after each adjustment, and let the gauges settle for a couple of seconds you will see if you have turned the screw the wrong direction, or too-much/not-enough. There is a routine for sequence of carb adjustment in the manual. You will need to practice adjusting the screws, but you will see one bank falls as the other rises and so on, it's the ancient art of Jiggery pokery.

Also; I always put a couple of household fans on the engine whilst doing this in an effort to keep the temp at mid range on your bike temp gauge/indicator. Temp change will possibly drive you to a state of madness with settings moving in and out of spec!

Good luck mate, enjoy your day.

 

[Zenuwlijer]

When you start the engine (probably on choke) be prepared to adjust the idle screw fairly quickly and get a near setting (rpm in the manual). Get heat in the engine and shut off the choke, and set the idle screw again to a nearness. Be prepared to be jumping between Carbtune Sychroniser and idle screw during running set-up.

I can go for a ride in about 20 minutes.

When I start the bike, I'll set the idle screw just enough so I can ride until the oil temperature gauge hits 80 degrees Celsius.

Then I'll find a parking lot and set the idle screw for real. After that I'll head straight for my home an grab the Carbtune.

 

[Screwloose]

I can go for a ride in about 20 minutes.

When I start the bike, I'll set the idle screw just enough so I can ride until the oil temperature gauge hits 80 degrees Celsius.

Then I'll find a parking lot and set the idle screw for real. After that I'll head straight for my home an grab the Carbtune.

Go for it dude!

Yesterday you claimed to be an amateur, now your working ahead of the game like a pro!

 

[Zenuwlijer]

Go for it dude!

Yesterday you claimed to be an amateur, now your working ahead of the game like a pro!

Well...

The bike won't start. It turns over, but won't ignite. I'll check the fuel supply.

View attachment PXL_20210719_114354422.mp4



Don't mind the "reserve" button. The previous owner wired it to only work on reserve. So "On" means no gas.

 

[Parminio]

Take your time. Make sure you didn't miss something simple.

 

[Zenuwlijer]

Fuel supply is working.

 

[Zenuwlijer]

Throttle is working.
View attachment PXL_20210719_122506573.mp4
View attachment PXL_20210719_122536741.mp4

 

[Parminio]

Check your electrical connections. Make sure everything got plugged back in properly. See if you're getting fire to the spark plugs.

 

[patate657]

Got a question for you gurus. This is a picture of my carbs when I pulled them from this 85' I have now. Been bugging me for a long time, but why are these lines on the picture not running to the air box like on other Gen 1's? This air box has no fittings for them too. Thank You