Sluggish acceleration.

[Banshee's Veil]

Then you should be running 110 to 120 Main jets. Not the 140’s. That’s your bog unless someone put older carbs on it. It’s been a few years since I rebuilt a set, but I I think 110 across all four, or 110’s on the outer carbs and 115’s on the inner carbs was stock on some.

I put the 40s and 110s back on. It idles so high I have to kill it. I'm going to try with the 140s and 40s.

Also my tach went out. It was erring low now its completely out.

[tarzan]

Sorry, my memory is a little fuzzy. But you do see that an SH needs 115’s and 120’s?

[tarzan]

If your tach stopped working it may have stopped charging as well.

[tarzan]

Really high idle is often times a vacuum leak, or sticky throttle cable or lineage

[Banshee's Veil]

Took her for a spin kill it upon decel. SHE PULLS. Hesitates off idle. Idles too high. I would say 2-3k. And creeps. Definitely a tuning problem.

[tarzan]

Did you sync the carbs?

[Bax]

Reset the pilot screws to 2 turns out and then lower the idle screw setting, probably had to set it open more with the 45 pilot jet to idle. Start the setup tune all over.

Bax

[Banshee's Veil]

Reset the pilot screws to 2 turns out and then lower the idle screw setting, probably had to set it open more with the 45 pilot jet to idle. Start the setup tune all over.

Bax

Yeah have to do it all over. I put the stock jets back on. She runs great. Rough idle and stuff but I haven't done the idle drop or sync.

[MarkD]

B-Veil, When you cleaned/rebuilt the carbs, did you use K&L jets/ Only genuine Mikuni jets are acceptable. I ran into many weird carb problems with my 79F after I cleaned and rebuilt them, using K&L parts. I replaced all jets with stock sized genuine Mikunis and it cured everything. Hang in there, carb problems can drive you crazy, but when everything's right, it's amazing.

[Banshee's Veil]

B-Veil, When you cleaned/rebuilt the carbs, did you use K&L jets/ Only genuine Mikuni jets are acceptable. I ran into many weird carb problems with my 79F after I cleaned and rebuilt them, using K&L parts. I replaced all jets with stock sized genuine Mikunis and it cured everything. Hang in there, carb problems can drive you crazy, but when everything's right, it's amazing.

I didnt buy any carb kits. I bought it all from dealer directly from mikuni.

[Banshee's Veil]

Alright bois, I pulled and installed the carbs 5 times today with different combinations. The best was the stock jets at 4 turns out.

However I found the culprit for the boggyness. Too much throttle tension. I never adjusted the tension at the grip.

She runs great now. I didnt have a chance to let her rip completely yet. Super smooth.

So I am running the pods. Should I rejet to the 45s and 140s now that I found out the problem with the bog?

[TopCatGr58]

Hey Banshee, there are a bunch of tech tips that could have helped you from the beginning. The jetting guide for equipment changes is 1 size UP for exhaust mod(4-1's vs stock), and 1 size up for Pod filters(vs) stock airbox. The 81SH came stock with 110's mains and IIRC 42.5 pilots. With the 4 turns out of the pilot screw, you will be safe going to 45 pilots, BUT you should only need 115, 117.5 mains, no where near the 140 size you have!!
I have an 81 SH with same style setup, running 45 pilots, 117.5 mains. Also, have you checked to ensure that it's hitting on al 4's by doing the exhaust pipe water spritz test? The stock coils are 39 years old, and generated maybe 15kV max. Would highly recommend getting some quality high output coils, ie. DynaTek or Accel.

Also what type of Pods did you put on? Again, there is info in the tech tips regarding the flawed cheap pod filters and how their mounting lips interfere with the air flow in the ports on the intake bell side. Tips show how to make modified velocity stack type mounts for them, or using the XS brand of pod filters from MikesXS/650 parts site that do NOT have the restrictive mounting lip.

The TACH receives it's signal from the ALTernator, and so often when the tach goes bad it indicates that the ALT isn't charging anymore, most common reason is the Reg/Rect goes bad. There are tech tips regarding how to check for that, if the bike isn't charging, the operating voltage drops very low, and the ignition won't work properly=poor weak plug spark at low rpms.

T.C.

[Bonz]

Lol, what’s the fun reading about tech tips when you can post up and get great advice from all the sages around here!

[Banshee's Veil]

Hey Banshee, there are a bunch of tech tips that could have helped you from the beginning. The jetting guide for equipment changes is 1 size UP for exhaust mod(4-1's vs stock), and 1 size up for Pod filters(vs) stock airbox. The 81SH came stock with 110's mains and IIRC 42.5 pilots. With the 4 turns out of the pilot screw, you will be safe going to 45 pilots, BUT you should only need 115, 117.5 mains, no where near the 140 size you have!!
I have an 81 SH with same style setup, running 45 pilots, 117.5 mains. Also, have you checked to ensure that it's hitting on al 4's by doing the exhaust pipe water spritz test? The stock coils are 39 years old, and generated maybe 15kV max. Would highly recommend getting some quality high output coils, ie. DynaTek or Accel.

Also what type of Pods did you put on? Again, there is info in the tech tips regarding the flawed cheap pod filters and how their mounting lips interfere with the air flow in the ports on the intake bell side. Tips show how to make modified velocity stack type mounts for them, or using the XS brand of pod filters from MikesXS/650 parts site that do NOT have the restrictive mounting lip.

The TACH receives it's signal from the ALTernator, and so often when the tach goes bad it indicates that the ALT isn't charging anymore, most common reason is the Reg/Rect goes bad. There are tech tips regarding how to check for that, if the bike isn't charging, the operating voltage drops very low, and the ignition won't work properly=poor weak plug spark at low rpms.

T.C.

I've never had a bike so picky about jetting.

I'll get the right jets. Yes she runs on all 4.

My headlight and running lights come on when the bike is on an increase brightness as I ride. Could the tach issue be something besides the stator?

[motoman]

Lol, what’s the fun reading about tech tips when you can post up and get great advice from all the sages around here!

Yeppers...............your Special will be happiest with factory reccomended 110main jets across all four carbs. Absolutely set idle mixtures using the lean-drop method(back each mixture screw out several turns, then slowly screw in until exhaust sound ever so slightly changes. Stop there and back mixture screw out no more than a quarter turn out. do other three mixture screws same way........then sync all four together using a manometer or four vacuum gauges which have to be accurate in relationship with each other. Now, re-check mixture settings then re-sync again......done.