carb modification question

[DGXSER]

Hey Doug, thanks for the invite, have to see how that coordinates with the family life tonight.

As to immortalizing me on film, I hope you got insurance on that camera!!

[dbeardslee]

Fred - Thanks for the heads-up on the other parts that are down those holes. Where's the fiche when you really need it . I'll have to go back out in the man cave and pick around for the other parts.

I just finished my preliminary experiments on the three carb bodies, and think I've found a pretty easy way to get the plugs out. Starting with a small drill bit I enlarged the hole in the plug. I put a depth gauge on the drill bits as the plug is .14" / 3.56mm thick. I allowed a little bit extra for the tip of the bit, and I mean just a little bit - the top of that mixture screw is really close to the plug. I kept going bigger and bigger on the drill bits untill the entire plug was drilled out. Gotta be careful with the big bit, and stop before you think your done. Pry with a pic and it should come apart. Then a dose of Free All, or PB Blaster, or whatever your favorite rust-buster on the top of the mixture screw. Let 'em percolate for a while and so far they've been coming out easy. I did manage to booger up the slot on one of the mixture screws, but EZ outs came to the rescue. That's it for the preliminaries - ready for the main event tonight.

I don't think I would attempt this procedure unless I had extra mixture screws in hand - better to be safe than sorry.

[DGXSER]

Doug,

Just in cse I am not there to protect you from you this evening, let me share my knowledge, you can search for a thread of mine (or three) on the madenning experience of breaking off an extractor in one of those mixture screws. It was ugly and no fun! Strongly advise against repeating that experience!!

[dbeardslee]

Don - I hear you, brother. I think I still have your number in my cell phone, so worst comes to worst....

[dbeardslee]

Fred - you wouldn't happen to know what size and material the little o-rings under the mixture screw are, would you? After getting them out of my test carbs I noticed that they had conformed themselves to the shape of the bottom of the tunnel. Definitely shot. If Eric's look like these, we'll need new ones.

[cywelchjr]

Fred - you wouldn't happen to know what size and material the little o-rings under the mixture screw are, would you? After getting them out of my test carbs I noticed that they had conformed themselves to the shape of the bottom of the tunnel. Definitely shot. If Eric's look like these, we'll need new ones.

If their for the 80 or newer carbs then MikeXS has a kit with the o-ring, the little washer and the spring for each adjusting screw. They also have a kit IIRC that includes all of the including the screw.

[dbeardslee]

Cy - the thing was, he was on his way over to do the work, so I was thinking I might have to make a trip to the hardware store. Luckily he already had carb kits and they were the good ones with the o-rings. Even had new mixture screws. All went well, and I'm waiting now to hear the results of the ride home. Sounded pretty good when it rolled out of my driveway.

[Ken Talbot]

Carefull - here's what happened last time I offered beer and steak for somebody to come work on my carbs...

[egleaves]

Ken, we didn't wind up with that many people, which is a good thing because I only brought a 6 pack!

Apparently the 6 pack was a sufficient offering to the carburetor gods because we removed and replaced my mixture screws (with the help of a drill press) and then color synced and vacuum synced DGXSER's bike as well as mine with no UH-OH's, WTF's, or WHADDA WE DO NOW's.

She starts better than ever, pulls hard and smooth up to about 4500, and then stumbles up to 5000 before taking off like a rocket. I'm going to try leaning out the mixture screws a quarter turn at a time to see if I can work that stumble out.

[dbeardslee]

Ken - Let me ask you this - we did two bikes (one's an 80SG and the other is an 81SH) last night and we adjusted the mixtures using a colortune. We did 'em the same way I do on my 79F. Both of them seem to have a stumble at 4500-5000 rpm's while mine pulls strong all the way to 9500. The only major difference is I'm running Mikes XS coils while both the specials have the stock coils. I'm relatively sure the carbs are very close to being dead-on right. I noticed with the colortune that the quality of the spark wasn't great. Would/could the coils be causing the stumble? I'm not sure where the voltage changes to the coils with the balast resistor in there, but I know that I brushed against the high tension wires on the SG while it was running and it bit me through gloves - not a good sign. Your thoughts?

And here's a pic of Eric 'The Drillinator Gleaves' attacking brass and aluminum with steel -



And here's a shot of the Gangstas Garage (or the garage previously known as the man cave) - gotta turn your baseball cap around backwards for admittance. 2-bays, no waiting. That's egleaves in the foreground, and DGXSER in the background wrenching on his near-mint 81SH.

[DGXSER]

Doug, mine seems to come in quicker, about 2-4. I also checked plugs and no 1 is fouled up badly again. I am seriously thinking of pulling that carb and putting in some of my old jets, same size, but original mikuni in that one. The only other thing I am considering is if the enricher on that carb is not seating back in right or something to make it run so much richer than the rest. Even though the colortune says it is there.

Doug does have a very nice setup there. Worked really well. Also, Doug is stretching the definition of "Nearly" in my opinion but thank you for the compliments on my bike! I also am impressed with the camera he used, I woudl have sworn it would have denied to take a picture with me in it! Oh, and hat on bckwords when working just keeps it from gettign knocked off everytime I have to get really close to see something with these decrepit eyes!

[dbeardslee]

Don - You might try switching your high tension wires on 1 and 4 and see if the problem goes with the wire. JAT

[DGXSER]

BTDT Doug, it stays with no 1. Funny thing is, all four looked nice and dark tan before I rebuilt them. So something has gone goofy in the rebuild.

[dbeardslee]

Might try raising the float (upside down orientation) 1-2 mm on #1 and see what happens. The fact that the other three look pretty good, and were set identically (or as close as our human hands could do it) and your only having a problem with #1 tends to suggest that it isn't the mixture doing it. When you adjusted your floats did you do both sides of the floats?

[DGXSER]

I know I checked both sides to be within my go-nogo gage settings. And I do know the fuel level is consistant as I checked it with the hose on the drain method for all four and they are all right in line.