Setting bike up on dyno - worth it?

[80GS1000]

Rather than messing around by trial and error with getting your engine and carbs dialed in after making modifications, is it worth the money to take your bike to a shop with a dyno to get it setup quickly? Will they be able to tell you the correct settings for your carbs to get the ideal air/fuel mixture throughout the rev range? Anyone have experience with this ?

The GS1000 just got K&N pods to go along with a V&H 4 into 1 exhaust and a Dynojet rejet, and well, it runs like crap. Would taking the bike to a dyno shop help get it set up faster?

Thanks for any help.

[Steve]

A dyno tune can do wonders if...

> they also test at less than full-throttle

> they have an exhaust gas analyzer to determine the fuel ratio

Let's face it...full-throttle is nice, but how much of our riding time is actually spent at that setting? :shock:
You can't just put the bike on the dyno and run it at 5,000 rpm to see what it does. You need to add the right amount of load on the dyno to get the correct throttle opening to test the correct circuits in the carbs. Yes, full-throttle jetting is critical. It is the basis for all the other jets, but you need to test all the others, too.


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[Dave8338]

What Steve says...Dyno tuning works great, however, few can afford the time on the dyno it takes to set things up for street use. In addition, you need to have a shop that is willing to either make changes, or allow you to make changes, to get things dialed in. TIME and the ability to pay for it, are the two biggest factors.

[chef1366]

Do you have BS 34ss Mikunis CV carbs? How do you have the Dynojet kit set up. I didn't follow the suggested jetting cause it was too lean. I had to go up one on the pilot jet. (2.5) Use the 132 Dyno main jet and try the needle set at the second notch from the bottom.

[80GS1000]

Do you have BS 34ss Mikunis CV carbs? How do you have the Dynojet kit set up. I didn't follow the suggested jetting cause it was too lean. I had to go up one on the pilot jet. (2.5) Use the 132 Dyno main jet and try the needle set at the second notch from the bottom.

Yep, they're the 34 mm CV Mikuni carbs.

Problem is, I made a mistake and took the carbs to the local GS guru while off the bike to have them cleaned and rejetted while doing all the other work on this project, so I don't know how they're set up. I should have waited to be done with the rest of the work and taken the bike and carbs as a whole over to his shop before monkeying around with the jetting. That, and I've never rejetted or taken apart carbs before. The main jets used were the DJ 118s (they're the ones missing from the jet kit), which appears to be wrong when using carbs according to the directions. I may just trailer the bike over to his shop and have him rejet it over there - the dude is a rockstar tuner and dragracer, his GS1100 dragbike does 8s in the quarter. Know any good resources for a newb on how to rejet carbs?

[Dave8338]

Sounds like you're going to have to go old school on the tuning for this one... \\/ Plug chops, color reads, jets and more jets!!! It's kinda fun though, and once you nail the curve, that first ride when it's right, is always the most fun!!!!!!! :-D Good luck and start with the mains.