Synchronizing carbs on a 1983 Venture

[mountainmanVR]

Howdy Venture techies,

 

I have a 1983 Venture, after several times of removing/reinstalling the carb bank I feel it is time to synchronize the carbs. I picked up a Carbtune Pro II 4 gauge.

Something puzzling me is something called a YICS SHUT OFF TOOL 90890-04068. Is this a requirement? If so, it appears I might need some advice...

 

Thank you in advance.

[luvmy40]

The YICS tool(at least one of them) is for the XJ series engines where the YICS chamber is milled into the head.

 

 

No YICS tool needed on the 83 Venture. You can disconnect the YICS lines and cap the ports during synchronization if you want. I just left mine capped off and removed the YICS chamber.

 

On a side note, I have seen mention in several different places of connecting the YICS ports front to back with vac line. It supposedly enhances fuel mileage...?

 

YICS is one of those engineering designs that works great on paper and should, in reality make a difference but doesn't seem to have much practical effect.

[mountainmanVR]

The YICS tool(at least one of them) is for the XJ series engines where the YICS chamber is milled into the head.

 

 

No YICS tool needed on the 83 Venture. You can disconnect the YICS lines and cap the ports during synchronization if you want. I just left mine capped off and removed the YICS chamber.

 

On a side note, I have seen mention in several different places of connecting the YICS ports front to back with vac line. It supposedly enhances fuel mileage...?

 

YICS is one of those engineering designs that works great on paper and should, in reality make a difference but doesn't seem to have much practical effect.

 

The Morgan site references that tool. This just seemed odd. I did not see any reference in http://www.venturerider.org/forum/showthread.php?495-Syncronizing-Carbs.

 

I am going to print off the procedure and head to the garage.. first is my Venture... then my 80, 850 Special.

[luvmy40]

Yeah, that's the tool for the XJ engines.

 

Just to be clear, Yamaha doesn't mention capping the ports for sync on the Venture and you should be able to get good results just leaving them alone. However, I have read that the YICS chamber on the Ventures is prone to developing leaks with age. That's why I removed mine.

[Yammer Dan]

The YICS on the 850 is a little different I think. Cain't remember how. but if my old brain is still clicking you need to disconnect YICS to sync?? On Venture that is simple just cain't remember 850!!

[luvmy40]

The 1980 850 Special shouldn't be a YICS engine.

[CaseyJ955]

The carbs should be synchronized every time they are touched. I synch mine even after needle adjustments, which in theory should have no effect on synch but I can always make minute adjustments and the bike is always happier. Theres that small window of tune where all is right with the world and it's hard to stay in that window without fine tuning a couple times a season. I have never used the YICS tool myself.

 

EDIT. I should clarify that the synching I'm talking about is on my Vmax, while the engine and carbs are essentially the same there is no YICS on it and I understand the YICS can make the bike less sensitive to maladjustment. I have never owned or synched a bike with YICS before. I'm just extra OCD about keeping carbs jetted and synched, maybe some throwback from my air cooled VeeDub days.

Edited August 25, 2016 by CaseyJ955

[Wilzhere]

Well first off I'm no Yamaha master mechanic,,,, but i bought an 83 venture about a 1 1/2 years ago. its been a nightmare for me. the thing seem to run pretty good found out they run real good on 3 cylinders. #3 would not fire right. finally after new wires it ran so so. then i rebuilt the carbs/ took them off at least 6 times, before going to the with new diaphragms from them people in Canada, started it up and it backfired once, the new diaphragms shredded, all but one. so i bought another set from http://jbmindustries.com/index.html that worked for me great And much cheaper price......then i did the Jason mod and the bike ran like crap ..no mileage, so i tried the shimming of the needles on the carbs no better mileage, went back put the YCIS back on changed the shimmed needles back to stock and finally after the umpteenth time trying to sync the carbs,i got it to sync... it runs good not great but real good and runs smooth , no stumbling at all at idle. and i get 42 +/- miles per gallon which is better then i was getting with all the mods and its consistent. so my suggestion is try to leave as close to stock as possible. I call it Yamaha nightmare. the real trick for me was rebuilding the carbs with the diaphragms from jbm... now im trying to fix the wiring kibosh that PO did, cant get the CMS to stop blinking its warning red little lite from hell, i narrowed it down to the reserve lighting unit, which i believe is causing the problems on the CMS found 4 wires which i believe was another MOD to remove the Reserve lighting unit from the system, heck they even pulled the connectors out of the plug in to the CMS.. Well to go on my, suggestion is to leave it as stock as possible. This was a Beta bike from Yamaha to keep the backyard mechanics hands off of it, so the stealership could do the repairs, i have found the two punch marks signifying 2nd gear repair and stat-or oil cooler repair, 2nd gear still screwed up so i short shift so i wont blow the transmission, so that's my experience with a 1983 Yamaha venture xvz12tk..i bought this for the creature comforts but it been a nightmare, don't trust it and i wont ever...I'm to old to go back to Yamaha repair school.Its a money pit.....i have parts i been trying to give away and cant.if you search my post you'll find them, maybe you can use them LOL Good Luck to ya!!!

I"m sure i'll be back to edit this post

 

PS i also have a !979 Shovel-head FXE bought new that has 160,000 miles on it with out a tear down,,,stock motor yea shes half USA and half Japanese and she leaks a little oil everyday ...but keeps on Putin

 

[mountainmanVR]

Well first off I'm no Yamaha master mechanic,,,, but i bought an 83 venture about a 1 1/2 years ago. its been a nightmare for me. the thing seem to run pretty good found out they run real good on 3 cylinders. #3 would not fire right. finally after new wires it ran so so. then i rebuilt the carbs/ took them off at least 6 times, before going to the with new diaphragms from them people in Canada, started it up and it backfired once, the new diaphragms shredded, all but one. so i bought another set from http://jbmindustries.com/index.html that worked for me great And much cheaper price......then i did the Jason mod and the bike ran like crap ..no mileage, so i tried the shimming of the needles on the carbs no better mileage, went back put the YCIS back on changed the shimmed needles back to stock and finally after the umpteenth time trying to sync the carbs,i got it to sync... it runs good not great but real good and runs smooth , no stumbling at all at idle. and i get 42 +/- miles per gallon which is better then i was getting with all the mods and its consistent. so my suggestion is try to leave as close to stock as possible. I call it Yamaha nightmare. the real trick for me was rebuilding the carbs with the diaphragms from jbm... now im trying to fix the wiring kibosh that PO did, cant get the CMS to stop blinking its warning red little lite from hell, i narrowed it down to the reserve lighting unit, which i believe is causing the problems on the CMS found 4 wires which i believe was another MOD to remove the Reserve lighting unit from the system, heck they even pulled the connectors out of the plug in to the CMS.. Well to go on my, suggestion is to leave it as stock as possible. This was a Beta bike from Yamaha to keep the backyard mechanics hands off of it, so the stealership could do the repairs, i have found the two punch marks signifying 2nd gear repair and stat-or oil cooler repair, 2nd gear still screwed up so i short shift so i wont blow the transmission, so that's my experience with a 1983 Yamaha venture xvz12tk..i bought this for the creature comforts but it been a nightmare, don't trust it and i wont ever...I'm to old to go back to Yamaha repair school.Its a money pit.....i have parts i been trying to give away and cant.if you search my post you'll find them, maybe you can use them LOL Good Luck to ya!!!

I"m sure i'll be back to edit this post

 

PS i also have a !979 Shovel-head FXE bought new that has 160,000 miles on it with out a tear down,,,stock motor yea shes half USA and half Japanese and she leaks a little oil everyday ...but keeps on Putin

 

 

Thank you for your insight. I just spent awhile setting up the Carbtune, then "Think" I got the carbs synced. All four are really close, not perfect. Does this mean I may have to adjust the pilot jets?

The PO really messed up this ride, I bought it in early July and have been tweeking everything. Rebuilt the brakes, had the forks torn apart twice, put in new Progressive springs, the right fork seal was leaking when I bought it, 2 seals later, it still leaks (I think it is being caused by small divets in that fork just above the seal. The left fork they used a fork seal washer on bottom, which caused that washer to slide down the bushing, subsequently causing the left fork to bottom out.

[Wilzhere]

Thank you for your insight. I just spent awhile setting up the Carbtune, then "Think" I got the carbs synced. All four are really close, not perfect. Does this mean I may have to adjust the pilot jets?

The PO really messed up this ride, I bought it in early July and have been tweeking everything. Rebuilt the brakes, had the forks torn apart twice, put in new Progressive springs, the right fork seal was leaking when I bought it, 2 seals later, it still leaks (I think it is being caused by small divets in that fork just above the seal. The left fork they used a fork seal washer on bottom, which caused that washer to slide down the bushing, subsequently causing the left fork to bottom out.

 

 

Ive been repairing on mine for over a year... lookin for a cheap ride ...LOL

you will never get them right on and yes you'll have to watch your plugs to determine your idle mixture, then re-sync...i have done all of what you have done and more... except the new fork springs how i fixed mine was to polish the fork tubes with 2000 grit sandpaper before mine sealed the finer the paper the better plus you will find the stem head bearings need to be replaced i used original springs in mine and they don't bottom out. the book says they should be 18"s in length mine were 17 3/4 bfd...my forks don't leak and they don't bottom out at all, but they did .....call me.Wil

[CaseyJ955]

Ive been repairing on mine for over a year... lookin for a cheap ride ...LOL

you will never get them right on and yes you'll have to watch your plugs to determine your idle mixture, then re-sync...i have done all of what you have done and more... except the new fork springs how i fixed mine was to polish the fork tubes with 2000 grit sandpaper before mine sealed the finer the paper the better plus you will find the stem head bearings need to be replaced i used original springs in mine and they don't bottom out. the book says they should be 18"s in length mine were 17 3/4 bfd...my forks don't leak and they don't bottom out at all, but they did .....call me.Wil

 

From what I read about the YICS it would be a bear to synch the carbs with that hooked up. If all things are as they should be, at operating temp, they should synch up fairly well. They should be VERY close. Also from what I'm reading it's better to have a properly functioning YICS than blocked off.

 

I know what you mean about it running on 3 cyl, the Yamaha V4 will run well. I had an electrical problem killing cyl #2 and I rode it around all day thinking it's just down on power a bit and not quite as smooth as it should be so I planned to go into it that eve and found a severed coil wire. I couldn't believe I had a completely dead pot and it still ran as well as it did. To make sure it's hitting on all cyl when I'm tuning I do the spit test on each downpipe to make sure each is carrying its aprox weight at idle. It's a quick backyard test but it told me in a hurry I had a bunk cyl when the coil wire was bad.

[camos]

how i fixed mine was to polish the fork tubes with 2000 grit sandpaper before mine sealed the finer the paper the better

Once you get the forks cleaned up or even better, before there is a problem put on some gaiters. These Rancho RS1952 fit well, are reasonably priced and seem to be of good quality.

 

 

Edited August 26, 2016 by camos

[mountainmanVR]

Thank you for all the responses. I synced the carbs yesterday - Success! What a difference.

If I get time today the fork (yes, only 1 side has an issue) will get fixed (3rd time is a charm, right?)....

I also plan to remove the spacer that came with the new Progressive springs, this should lower the front end 1" and help control-ability on gravel... Yes, I live on a gravel road up

a mountain... Control is crucial....

[mountainmanVR]

Ok VR enthusiasts... I pulled that fork apart, smoothed the divets (made by PO) as much as possible.. put her back together.. will ride this afternoon.

[CaseyJ955]

Thank you for all the responses. I synced the carbs yesterday - Success! What a difference.

If I get time today the fork (yes, only 1 side has an issue) will get fixed (3rd time is a charm, right?)....

I also plan to remove the spacer that came with the new Progressive springs, this should lower the front end 1" and help control-ability on gravel... Yes, I live on a gravel road up

a mountain... Control is crucial....

 

I also love on a crazy crappy gravel raod, would love to know how you get them setup for best control under such circumstances in regards to spacers and air.

[mountainmanVR]

Mine is a curvy, uneven, 20 + degree (elevation)... With the new progressive springs without the pvc spacer & 7 psi in front, auto low in back w/ damper set at 1... perfect..

[cowpuc]

I dont live on 5 miles of gravel road anymore but still like to do two track, single track and off road my 83's on occasion.. For me its Progressives, just under an inch of preload (I use Copper pipe end caps cause I dont care for the possibilty of PVC plastic wearing off and floating around in my fork hydraulic system), 12.5 weight fork oil (Honda use to spec ATF for forks back in the 80's before cartridge valves - used it for years in my dirtbikes but found it to light for my touring bike two tracking packed with gear and riding two up needs) and no air. Seems to give the most suspention travel on big bumps and running 50 or 60 on gravel roads in studder bumps they sure seem smooth.. I also run my rear mono at 70 pounds and number 4 on the dampner.. Drop to 45 when one up and riding single but leave the forks alone and wowzy = still awesome in the corners.. :bikersmilie::bikersmilie:

[snyper316]

I hate gravel it's not bad but when they think white chat gravel is the fun stuff

 

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