3 Dyno Jet Kit GS 1000 Dyna III electronic ignition

[Anonymous]

There isn't much vacuum on full throttle. Remove the air-box and there will be even less. Increased air pressure through carb (closer to atmospheric) as a result of serious intake mods means there may not be enough vacuum to hold the fuel tap open, leading to fuel starvation as the carb float bowls run dry. The obvious cure is to fit a manual on/off tap.
This fix worked for me with my particular bike. Having said that, my old '77 GS 750 ran perfectly with S&B pods and a stock vacuum tap, which is where the theory falls flat! Maybe some bikes are affected and others aren't, who knows?

As an aside, why did you keep your float bowl vent tubes? I removed mine, as per the dynojet instructions, though I have to confess I can't figure out exactly what they do.

 

[KEITH KRAUSE]

To Lloyd and ThunderDan1.

To Lloyd and ThunderDan1.

Thanks for mentioning the float bowl vent tubes. My mistake. You must REMOVE them for the fuel to flow right. I just got mixed up. So if T-Dan is reading this, he knows. I would'nt want to give wrong advice, so thanks!
As for why they must be removed, especially ''California models'', I wondered too because I did'nt like the idea of dust maybe getting in the carbs. So I called Dynojet and they said if the tubes are left on it creates a ''vortex'' or a turbulence effect that interferes with fuel flow, and it's worse in windy conditions. It's over my head. But just to see what would happen I put them on. The bike ran for 1 1/2 miles and then acted like it was running out of gas. I removed them and it was fine. So much for that experiment. Strong crosswinds still effect the carbs but it's minor. I wanted to put a small piece of foam over the vent openings to stop dust but did want to maybe cause problems. Stock bikes run well with the tubes, but not pod filtered bikes. KK.

 

[Anonymous]

Thanks for the update KK I’ll be sure to remove the vent tubes. I’ll also be using your carb settings I’ll let you know how it turns out. Also, what aftermarket equipment do I need to have my cams degreed someone mentioned an adjustable cam sprocket or something like that?

 

[Dink]

Dan slotted cam sprockets is all you need.
Dink

 

[KEITH KRAUSE]

Slotted cam sprocket.

Slotted cam sprocket.

Thanks for the update KK I?ll be sure to remove the vent tubes. I?ll also be using your carb settings I?ll let you know how it turns out. Also, what aftermarket equipment do I need to have my cams degreed someone mentioned an adjustable cam sprocket or something like that?

Vance&Hines charged me $50 for the sprocket and labor to set timing was 2 hours @ $55/hr. 3 years ago. The engine was on their bench,so the labor would be more if you bring bike in. If you were to do it yourself you would need a degree wheel,a top dead center tool(two-stroke timing set),a
factory shop manual and general tools. The stock cam sprocket can be slotted with a rat-tailed file. I have never tried cam timing. Keep us posted. KK.

 

[Anonymous]

I've had lots of experience with the dynajet kits on all types of bikes as I am a Motorycycle technician. If you have aftermarket exhaust and/or aircleaners YOU MUST rejet your carbs. Dynojet kits are the simplest and most effective way to do this. I have yet to run into a problem with any of these kits from my own stage 3 in my 79 gs1000 to a 103 cubic inch Harley stroker Twin cam to just about any other bike on the market. Also I have logged thousands of hours on a Dynojet 250 dynamometer trying to get the best possible "tune" out of many differnt bikes and the dynojet kits are damn near spot on right out of the box. You must ensure that you Synch your carbs after every jet change or more importantly every needle change to ensure you are getting accurate results.