SET Valve Mod Question K6-K7-K8 600/750 (Updated w/K5-K6 1k info) - Page 5

xtremekramer · 05-20-2009, 07:35 PM

So I am about to do this mod since the damn FI light has been on for weeks. Seems like most of you have been happy with the results. Has any one noticed any difference in the low end torque after the mod? The service manual states this is the purpose of the valve. I know most of us agree its for passing sound tests...however being an engineer it makes sense you would loose some low end torque with the difference in back pressure. Just wondered if it was even noticeable? Or if noticeable the added throttle response made up for the difference in low end torque that that was lost that you just don't care about it?

I will let you know how it goes once i get mine done. Figure it can't hurt since the dealer wants to replace the motor saying it will take two hours of work at $75/half hour plus the cost of the motor. Figure a free mod is well worth a try.

jk750 · 05-21-2009, 09:02 PM

It's definitely a noise control solution. It says so right in Suzuki's first generation SET valve literature. An added benefit might be improved low speed torque, but that is not the reason for the valve.

If the low speed torque improvement was so advantageous, Suzuki, Yamaha and the others would be using them in racing to get the drive out of the corners with the Ducatis.

xtremekramer · 05-23-2009, 01:59 PM

Well all in all it took about an hour. Almost all of it was trying to get the plastic tail piece off! There is a screw that i was having a hard time getting to break loose at the weird angle you have to attack it at. It's been raining here pretty much non stop the last few days. Hope to get out to ride it this weekend. Took it down the street and back just a few minutes ago. Seemed to stumble when i first got on it. Other wise was doing fine. Will be curious if that goes away once the bike runs for a bit and the computer relearns the system performance. It was raining so i didn't get to really test it.