3 Dyno Jet Kit GS 1000 Dyna III electronic ignition

[KEITH KRAUSE]

Vance&Hines billed me $50 for the slotted cam sprocket,and the labor was 2 hours to set timing,but my engine was on their bench and was a total rebuild. The improved power was worth the trouble/expense,at least for me. I can't tell you how much the timing itself contributed to power,but all the mod's combined(1085 kit/timing/pipe/filters/ign'&coils)really impressed me. It runs much stronger than stock and is still dependable. KK.

[KEITH KRAUSE]

For Brit7.11

Hi again. Just thought I'd send the article's own words about cam timing suggestion. This is from the Dec.'84 Motorcyclist mag:'Another important variable in stock engine performance is cam timing. Two stock bikes that differ in power also probably differ in cam timing. Stock GS1000's often have intake-cam lobe centers of 115 or more degrees. With an intake cam this retarded, warm up is slow, the engine runs hot, carburetion is difficult to set correctly and the powerband is narrow in rpm. With intake-and exhaust-cam lobe centers set BETWEEN 104 and 106 degrees, your Suzuki will have a broad powerband, excellent throttle response and the best compromise between peak and low-rpm power. The mileage will be at its best too. Time the cams,it is well worth the bother'. They did a 'how to' article on cam timing in the Oct. '80 issue. Maybe they can still send to anyone interested. I may also send it ,if I can find time and there is interest.(I am a REAL slow typist) KK.

[Anonymous]

Another couple of tips for Thunderdan1:

I have a '79 GS 1000, had similar running problems and have performed near-identical mods to those you intend.
Fit a good inline fuel filter, especially if your tank's a little rusty (in England, all tanks are rusty!). You want one that pulls everything out, right down to the ultra-fine stuff that looks like brown chalk dust. Some plastic mesh types let this through. Result? Blocked carb emulsion tubes (the holes in these things are tiny) leading to loss of power/misfires and, eventually, a dead bike in the middle of nowhere. The standard petcock filter inside the tank may as well not be there, in my opinion. I fitted a paper-element type meant for some car, cost peanuts and works perfectly.
Next up, if you do go ahead with your stage 3 intake mods, you'll definitely need the Pingle fuel tap (if my experience is anything to go by).
I mention this just on the chance that you decide not to bother with one. Stock vacuum taps rely on a low intake pressure to keep them open. Pod filters increase the intake pressure. The result is a motor which runs great until you decide to give it some hammer, whereupon the carbs run dry! I discovered this while trying to pass a truck with another coming the other way... I then spent the next few days messing around with different float heights, checking for blocked emulsion tubes/jets and all sorts until discovering the answer in a tuning book.
Stock coils/HT leads? Throw 'em in the trash now if you haven't already.
I traced a mystery misfire to mine. Just because the LT/HT readings check out on an ohmeter, doesn't mean the internal insulation is still ok. Pair of Dyna 3-ohm (green) coils and a set of Taylor leads did the trick.
Finally, a colourtune plug is worth it's weight in gold for initial carb setup when installing your dynojet kit, at least for getting your idle mixture correct. You can then go from there. I guess no DIY job will ever be as accurate as a professional dyno setup, but then there ain't one that costs as much, either! One thing I noticed: the base settings in the instruction book give you an extremely lean-running engine (not good!) Follow the instructions carefully and you can't go far wrong, but be ready for a few carb strip-downs/rebalancing...
All the above results from trial and error. Hope some of it might be of use to you.
p.s. Brilliant site!

I discovered a

[Anonymous]

Well fellas it seems that I have really initiated quite a question here. Unfortunately I’m in quite a quandary as weather or no to install the stage III jet kit. I want my bike to run well but I also want the extra power. Anyhow the stage III might still be a practical investment seeing as how I’ll be upgrading the engine when it finally needs rebuilt, cams, higher compression pistons, port & polish etc. Well keep the responses coming guys I really appreciate the advice.

[KEITH KRAUSE]

Petcock tip.

I agree the pingle petcock is an improvement. But I'm not clear on your increased intake pressure thing. The stock petcock has a diaphragm that is kept closed by a spring. The carb vacuum defeats the spring to allow fuel flow. You say pod filters increase intake pressure. Are you saying that the increase in pressure actually works to close the petcock diaphragm? How? By applying suction to the other side of diaphragm? The fuel flows by gravity,the rate controlled by the float needles. How can pod filters or any filter create a suction that would close the diaphragm? Am I reading something wrong? I know which direction the spring/diaphragm move. Any increase in intake pressure would make the petcock open quicker. Let me know. I'm not saying you're wrong, I just don't understand how. KK. 'PS'. I still have a stock petcock and pods, but I have never had a fuel starvation problem.

[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.

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.

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.