Problem after carb cleaning

[rvcullen]

I had a frikin mouse chew a hole in my air filter without realizing it. Ran the bike about 1000 miles or so before I got to seeing it and my carbs paid the price with lots of dirt in them. Funny thing is the bike ran great the whole time, no issues.

My problem is now, after I had to disassemble all the carbs and clean them out, blew them out and double checked my work. Everything seems to work ok and no leaks, or damage except for 2 of the diaphrams that fell apart (inner sleeve thing) which I just reglued.

The bike starts, chokes good, and idles fine, but will immediately bog down and bacfire through the carbs when I give it quick gas. A slower throttle gets the rms up, but still gives me blowback through the carbs. BTW, valves are set good also.

I tried resetting the adjust screws back down to 2 turns and it got worse. When I originally took things apart, most screws were at 3.5 to 4 turns already, is that too much already?

 

Does anybody know if I should mess with the slide needle at all? I do have a colortune coming so I can try a better A/F mix setting, but wonder what the factory setting is for the slide needle.

 

Sorry for the long winded post, just trying to think of anything.

[nyjerry]

This might be a dump answer but do you have the air cleaner back on it. They don't like to run with out it.

[greg_in_london]

2 of the diaphrams that fell apart (inner sleeve thing) which I just reglued

Another shot in the dark, but as I'm not quite sure what you mean here - are the diaphragms as flexible after you reglued them as before ? If the piston doesn't move freely anymore then you might get this response.

 

How far did you tear then down, anyway ? Did you get into the gasket behind the jet body and the o-ring on the nozzle ? Were they okay/did you replace them ?

 

Just thinking out loud.

[skydoc_17]

Hey Robert,

Sorry to hear about your bad luck with that mouse! Did you Sync. the Carbs. after the reinstall of the Carbs? Did you check the line that goes to the boost sensor, (Cylinder #1, front left) to make sure it didn't come disconnected from the sensor? To be honest, if you have synced. the Carbs. and the sensor is connected, sounds like bad Diaphragms to me. I would not compound you problems right now by reshimming the slider needle, I would also try 21/2 turns on the mixture screws. Keep us posted on what you find out and have done.

Earl

[GeorgeS]

Idle mix jets, anything about 2 1/8 to 2 1/4 turns CCW. ( Engine should run OK )

 

Did you remove the idle mix needles to check if the seats have been damaged.

 

when you Replaced the diaphram covers, are you sure the gaskets made a good Seal ??? The big O-Ring.

 

---- AND THE little one ??? It has to be installed !!! ( Its easy to miss on reassembly )

 

Check your " PULL" throttle cable, at the left Fwd Carb-- Be sure it has about 1/16 to 1/8 inch of " Slack " before trying to do a Carb Sync. If no slack, then most likley the last carb sync ( If Ever ) was botched up.

 

If the last Carb sync was done, with Two Diaphrams, with Holes in them, then most likley you need to just do a Carb Sync.

 

Also, you might as well order a new set of diaphrams, !! your just delaying what is sure to come. The Glue, won't last forever

 

Also, check the Clamps Above and Below the Carb bodies !! Double check for any Vaccume Leaks.

 

Are the Vaccume port Plugs re-installed ?

[rvcullen]

Okay, so Thank you for all of your responses. here's where I'm at, I bought a colortune and it came in yesterday so I was tinkering with it and seem to get 3 of the cylinders to adjust the A/F pretty easily, but the last cylinder (right, rear) will only give a "somewhat" decent mixture at idel when the screw is about 6 turns out!

I am not able to get any cylinder to give a good idle mixture until it is about 4 turns out, which is the way it actually was set when I first started this. I wonder if there is other leaking going on. I did check the nipples and any ports, intake manifolds, etc for leaks, but they all look good.

I also took the slider out of the right, rear cylinder to see if the pin was set at factory, and it is. I hope I don't have to take this thing apart again.

Right now, i ran the seafoam through the carbs straight and ahve it sitting for a few hours, to see if it gets better.

BTW, the gluing I did was not actually to the rubber parts, it was between the plastic slider and the metal sleeve that goes in it. 2 of the carbs had these coming apart. All rubber parts and gaskets were in very good shape, and it really had no blockages in the jets. I just hope i didn't blow air through the mixture screw and force something in there to block it.

[jasonm.]

Very interesting, my right rear(#3) also needed more CCW turns to get it on the money. I set mine using a digital tach, watching for changes as I adjust. #3 took about 4 turns. My other carbs only needed 2.5 to 3 turns.

[GeorgeS]

Do you have a set of Mercury Stiks, or the " Morgan Carb Tune tool " ???

 

The Correct Setting for the Idle Mix Adjusting Jets, is 2 and 1/4-- to --- 2 and 1/8 turns CCW from full closed. Set them all the Same---

 

Then Set the Throttle Pull cable to have 1/8 Inch of Slack.

 

Then, Do a Carb Sync with the Morgan Carb Tune Tool !!! ( or mercury stiks )

 

See: the Service manual for the Sync Proceedure----

 

Your " Main Idle Adjust " is under the left Fwd Carb "

 

There is One Sync Screw on the left side, and two on the Right side.

 

After this is all done, then do ---- """ Very Minor Adjusment"""" -----of the Idle mix Screws. !!!

 

Untill you do the " SYNC " of the mechanical linkage, you are just bucking the wind !!

[rvcullen]

That's the big problem. I can't get that last carb to run really at all without being 6 turns or so. I just took the carbs apart again lsat night thinking I missed a blocked jet or something and really couldn't find anything bad. Reassembled, reinstalled. I synced them all up, no problem there at all. Checked idle (about 1000) and rechecked the mixtures.

Anybody use the colortune before, when I set it to just before a yellow flame, all of the carbs end up being at about 4 turns. The last carb i can't even get to run right at all without misfiring unless it is about 6 turns, very odd.

I check anything i could think of, even vac tested the YICS system and all hoses, etc.

Don't know what else to do but run it like that. Anybody know where I can get a new carb from??? AAAAAHHHHHHHHHHHH!!

[GeorgeS]

Well its sounding like there is some problem with that carb.

 

Have you Removed the Idle Mix Jet, and Inspected those very fine threads on it.

 

Are the threads Damaged ?? If threads are damaged, in the carb body, most likley you will have to find a replacement carb.

 

Is the Needle jet Damaged ??

 

Are you absolutly sure all 4 throttle Plates, are going to " full " closed position with the hand throttle ?

[rhncue]

Have you looked beyond the carb. to the basic engine condition? You must have good compression for a cylinder to have proper draw for the carb. to work properly. A sticking valve, a chip of carbon or a valve out of adjustment will affect the compression.

 

Dick