Which to keep, '74 or '75 vm28sc's?

My bike has 1975 vm28sc's on it that work fine except one of the tubes that feeds the enrichment circuit is cracked and missing it's restrictor. This means one cylinder is getting tons of gas when the choke is on, stinking up the place (I love the smell) and causing some spitting and sputtering. Once the choke is off the bike runs great.

Today my local craigslist produced a set of 1974
vm28sc's that were dirty but in good shape.
I've since cleaned them up and put them,on the bike, started right up and ran fine.
The new set is missing the plastic piece on the choke lever, everything else is there.
Throttle pull is harder due to dual return springs.

Any advice on which set to keep? Any real world problems with one vs. The other?

I did read the '75 had a needle that was leaner in the midrange, which is the set I've been riding with.
I hope to ride with the other set tonight or tomorrow.

Those look like 73's to me. The 75 was a little quicker than the 73-74's. Slides are 2.0 on the early carbs.
Steve

Overflow tubes = 1974 as I understand it.
But I'm wrong several times a day.

74 was the Z1a. It did have overflow tubes, so did the 75's.
73-74
Needle 5J9-3rd
Needle jet P-8
Cutaway 2.5Main 112.5
Pilot jet 20
Air screw 1 1.2
75
Needle 5J9-2nd
Needle jet O-8
Cutaway 1.5
Pilot jet 17.5
Air screw 1 1/4
Steve

swest wrote: Those look like 73's to me. The 75 was a little quicker than the 73-74's. Slides are 2.0 on the early carbs.
Steve

73, no overflow
74, overflow

I may be wwwwrong. :lol:
www.wgcarbs.com/index.php/using-joomla/e...ategories/92-z1-carb
Steve

Well, the bike rejected the new carbs..... :sick:

The carbs worked great, 3 miles into my test ride the #3 plug decided to shoot out of the head.....so there's that. :pinch:

I'll be asking about options in the engine thread..

Oh SHT. :ohmy: Heli coil.
Steve

MadShad wrote: Well, the bike rejected the new carbs..... :sick:

The carbs worked great, 3 miles into my test ride the #3 plug decided to shoot out of the head.....so there's that. :pinch:

I'll be asking about options in the engine thread..

OUCH! that sucks when that happens. Do you know anyone that works at a Ford dealer? Or on newer cars & trucks?
Ford Triton engines 4.6, 5.4 ltr are notorious for spitting plugs out of their heads also, just like happened to you.
Or when trying to change the spark plugs. There are several repair kits sold to repair plug holes right on the engine.
Just google "Ford stripped spark plug" Snap On tools top priced kit is $400, the cheap box auto store sell cheaper.
www.oreillyauto.com/site/c/search/Spark+....oap?mc=LIS&mn=Lisle
If you could find someone with the kit? They sell the inserts cheap.
Good Luck.
I sent you a PM about carbs also.