Jump to content

Recommended Posts

Well, just got my 83 First gen back from a local shop and the whole ride home I've been sick to my stomach. I took it in for oil change, spedo replacement, and to synch the carbs. He said that the carbs are mechanically synced and that wouldn't be necessary. He did say he adjusted the screws to smooth it out. Boy now I'm messed up. This thing went from running 80% good to 45% good. Feels like it is missing or even possibly fouled out. I can't take it back till Monday but I feel like I messed up by allowing them to work on this carb. I described the synch tool with the four liquid levels but apparently that didn't work.


I hindsight I should of ordered the new tci that Dingy sells. Wondering if anyone has any suggestions on how I can communicate to this shop on Monday and if there is anyone in the southwest Missouri area that I can hire to get the carbs back right. Trying to be patient. I'll look in the morning to see if something came unplugged or what but I pulled it out of the shop like this. On top of that they had it for a week and a half.




P.s. It has ran great for several years now but always felt like it was only on 3 cylinders after doing the cold start test with the occasional back fire through the carb. But even the. It ran better than this. I was getting about 26mpg. So in hindsight it might just be the tci.

Link to comment
Share on other sites

The Ignitec ignition is the bomb. That's the name of the company that makes the ignition Dingy orders for us. I have one and couldn't be happier. Dealers and shops. Those that don't TEST DRIVE the car/bike.computer, stereo, whatever should have their license pulled. Let's go back to the scientific method. You ALWAYS TEST the correction right? The carbs are mechanically actuated but not sync'ed. The mechanic at the place you took your bike to probably has trouble distinguishing body orifices with holes in the ground. He probably grew up with fuel injection, that's a whole new ball game. You need a carb synchronizer to sync the carbs. There is a member here that made one that is 100% digital. look it up; he might be selling them;with that you can do your own syncing. YOu should be getting UP to 50-52 mpg at 55 to 50 mph. I wouldn't pay them any more $$ either. You pay ONCE to fix things, that the shop doesn't test the fix ain't YOUR problem. The customer shouldn't be the road tester, the shop should be.

Link to comment
Share on other sites

As much as I would like to sell you a TCI, you have carb issues at this point.


With the motor cold, check and see if exhaust tubes heat up evenly, best way is with an infrared temp gun. Harbor Freight sells them in $20~30 range. If you have a cold cylinder, it might be TCI. A bad sync won't prevent a cylinder from firing and heating up. I don't think that just a bad sync will have as drastic effect as you describe though.


Something else to try is called a Shotgun treatment to the carbs. I just did this for the 1st time to my 83 (Tweety) due to a nasty backfire on one cylinder in mid range on deacel. It eliminated that. It helps clean out many of the carb circuits without removing carbs. PDF attached of procedure.


Link to author's web site is next, though PDF has complete description & pictures that he posted.





Lvlhead's Vmax - The Shotgun.pdf

Link to comment
Share on other sites

Thanks for the replies. He said he adjusted the air mixture screw on one of the carbs. And doesn't sound like they own a carbtune, like myself. See some on eBay that ships from CA. Before I took it in I tried the exhaust temp and seemed like one was cooler than the rest. before my Colorado trip in August I'll get the new tci and carbtune. At this rate might be next week. It's not running good at all now. I might even pull plugs to see if one fouled for some reason.


Thanks again.

Link to comment
Share on other sites

It sounds like either your mechanic does not have a clue on these bikes or is a rip off. I would not even go back to him other than to insist on at least a partial refund.


There is the digital synchronizer that a member here invented, but it only comes as a kit, you have to solder all the components to the circuit board. The most popular sync toll on this site is the Morgan Carb Tune, you have to order it from Europe.

Link to comment
Share on other sites

I just went through the carb sync episode. I got a Motion Pro manometer for Christmas. It didn't work. Bubbles kept forming in the tubes and couldn't get them out. I called Motion Pro and they said it needed a refill kit that I should buy. Don't buy a Motion Pro. I ended up making my own with about 50' of tygon tube, 2 tees and mounted it on a vertical 2"x4" with trans fluid in the tubes. I did get my sync done with this homemade device.


If I buy another carb sync unit, it will have gauges because you don't have to worry about sucking fluid into the engine with those. A manometer is no good if the carbs are way out of sync. You will suck fluid into the engine before it even starts if you are not really quick.

Edited by BlueSky
Link to comment
Share on other sites

So you say it feels like it's missing?


If it still has the OEM spark plug caps, pull them off the wires and meter them.


They just unscrew from the spark plug wires.


It's quick, easy and no cost.


Mine was running, but I was chasing an intermittent miss and poor MPG. It was also occasionally sneezing back through #2 carb. I metered my caps and found #2 showed as an open. Took it apart, discovered it was corroded inside, cleaned it up and my miss was gone. What was happening is the corrosion had increased the resistance so that it showed as no continuity on the meter, but the spark energy would jump the resistance and still fire the plug at higher RPMs. Crappy running ensure everywhere as a result.


If you do find something similar, remember NOT to clean the little blueish "bar like" object that is inside the cap. It's actually a resistor and anything abrasive will ruin it. Just hit it with electrical contact cleaner and put it back in. It's the brass and spring components in there that corrode and add too much resistant to the circuit.


Here's more or less what you are looking at:




That's an ngk cap, but same stuff different pile for the OEM cap.


The other option is to just toss the oem cap and replace it with a new NGK cap with the proper resistance.


I'm not saying your carbs aren't the problem, but I also chased what I though was a carb issue until I found that one PITA spark plug cap. You description sounds pretty much bang on with what I was fighting with.


Oh, that shop that said a sync is not required because they are "mechanically linked" and he "fiddled with the screws to smooth the bike out"; never go there again. They don't know what they are talking about. You must have had the "tire changing guy" working on your bike or something. The V4 Venture, just like all multicarbed vehicles, must have the carbs synchronized to run efficiently. That's why the procedure is in the manual and there are sync ports on the intake manifolds.


Good luck.

Edited by Great White
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...