Katana College Study

[VexxeD]

I've picked up a 92 Katana to use in a summer independent study. I want to look at the widespread use of aftermarket exhaust for performance gains. Currently my bike doesn't run well (doesn't hold idle, revs high, and stays for awhile) I know this is due to a carb leak and I already know about carbs 101/102. This is the first half of the class, which scheduling has prevented me from starting.

I need to find some published result using a aftermarket system ( preferably Vance & Hines - http://www.vanceandhines.com/store/s.../suzuki/12540/)
A Dyno reading would be ideal, a published result basically being a wet dream. Do anyone know of any resources on the subject? I was surprised V&H doesn't publish results similar to aftermarket car exhaust manufacturers. Any help would be appreciated!

[Kreylyn]

Well, an after market exhaust alone does not improve the over all performance of the bike. Actually may slightly reduce it with out compensation for the new exhaust being made elsewhere. Stock exhaust systems are tuned to provide a better street ride performance. Quiet, more power down lower in the RPM range. Most after market exhausts will move the existing power higher up in the RPM range. It's just a change in where the primary power range of the engine is.


An after market system is used to assist other modifications that will improve performance. A jet kit for example is generally necessary to compensate for the change.


A jet kit will improve performance, but not power. A jet kit allows you to better tune for the RPM curve for a smoother delivery of the power generated by the engine. That's the improvement.


If you want more power, then engine modifications would be necessary to increase power. Then, carb jetting and exhaust swapping happens to better take advantage of the engine mods.


As such, you won't find much about an exhaust improving the performance. You might find someone who has, or will be willing to post some dyno results, but those are going to have more than just exhaust changes. Almost all of them would include at least jet kits, if not cam mods and other things done.


Krey

[Maverick.Marq]

Is it purple? the purple 92's go faster.

But in all seriousness, I have a 92 600 (purple of course) with the SS2R exhaust
and jet kit ( mains only)

no access to a dyno or anything like that, but I can tell you that they do need some sort of further adjustment carb wise. I get very low amounts of torque under 4krpm

[Kreylyn]

Is it purple? the purple 92's go faster.

But in all seriousness, I have a 92 600 (purple of course) with the SS2R exhaust
and jet kit ( mains only)

no access to a dyno or anything like that, but I can tell you that they do need some sort of further adjustment carb wise. I get very low amounts of torque under 4krpm

I'd suggest you double check for arcing from the plug wires/plug caps is going on, or a plug boot not securely on. Every time I've experienced low rpm power issues, it's been because of that primarily.


Krey

[VexxeD]

A jet kit will improve performance, but not power. A jet kit allows you to better tune for the RPM curve for a smoother delivery of the power generated by the engine. That's the improvement.

Krey

Thanks for the info! I'm trying to get with a local Dyno shop so I could see the change in power delivery along the entire RPM band. I also have some different jets on order and they will be changed, adjusted and synced between tests.

[Maverick.Marq]

I'd suggest you double check for arcing from the plug wires/plug caps is going on, or a plug boot not securely on. Every time I've experienced low rpm power issues, it's been because of that primarily.


Krey

Thanks Krey, my spark plugs look good, but are probably due for a replacement, I also think my battery is getting a little weak, people kept taking it off the trickle charger all winter.

I also plan on doing a valve clearance check ( have never done it) and don't know when it was last done. I was gonna do it this weekend, but it's too nice to have the bike in a garage

[Kreylyn]

Thanks Krey, my spark plugs look good, but are probably due for a replacement, I also think my battery is getting a little weak, people kept taking it off the trickle charger all winter.

I also plan on doing a valve clearance check ( have never done it) and don't know when it was last done. I was gonna do it this weekend, but it's too nice to have the bike in a garage

Just to clarify, I wasn't talking about the plugs. I was talking about the wires... if they are not connected tightly, or have a bad spot that is arcing... that's a loss of power especially at low rpms.

Best to check for that by running the bike with the tank off, in low light/darkness to see the arcs.

Krey

[Maverick.Marq]

Just to clarify, I wasn't talking about the plugs. I was talking about the wires... if they are not connected tightly, or have a bad spot that is arcing... that's a loss of power especially at low rpms.

Best to check for that by running the bike with the tank off, in low light/darkness to see the arcs.

Krey

I'll do that soon. I'm too busy installing my race tech springs and emulators

[VexxeD]

So, I'm cleaning those carbs from the college project I asked you about before and I found the washer from all four main jets is missing! The carb has had work done on it before and this is when I suspect this happened. The vacuum o-rings on the top cap are all missing too!

How would this affect over all performance? I'm sure there a has to be some effect. But for now I'm waiting since the local Suzuki dealer isn't open today. Is there another source for these washers? I doubt they are a general part.