rs34's

timebomb33 wrote:

about the only flatslides that dont rattle alot are the ones everybody is putting on there harleys the 42,45 mm mikuni flatslides are supported by roller bearings up and down bothsides so it keeps them quiet.

I think those are HSR´s not RS that are used on HD´s. Roller-bearings are also in Mikunis TMR -line-up. These are the evolutuion of TM and RS I think.(Sorry about links in German)Maybe you´l find same in on Sudco etc. pages.

www.mikuni-topham.de/DEUTSCHSITE/Deutsch/FRAMEDEUTSCH.html

These are my wet dream. Mikuni TMR36:

I tried the bike without the baffle and it seemed to run even better - with less clacking! I don't know if they really rattled less or if I just couldn't hear it! Anyway, I'd love to ride without the baffle but we get tickets around here for such crimes against society.

Now that the carbs are dialed in, I think I'll try another exhaust. I have a nice big Yoshi pipe I've been dying to try out - nearly 3" of pipe all the way back! That V&H street system I have really seems to be choking the 1260 motor.

79MKII wrote:

That V&H street system I have really seems to be choking the 1260 motor.

In my experience, the V&H pipe will work well with a competition baffle. Stock baffle chokes the exhaust and no baffle seriously hurts low end and mid range and ears. Competition baffle is the answer.

Z1109R Fin wrote:

...Mikuni TMR36....

Beautiful carbs. But appear more of a down-draft design, and am dubious as to whether feasible on KZ's where carbs are fitted in level position.

Good Luck!

i have no rattle or clack in my RS34's. i have a 2 1/16" I.D. baffle. sometimes u may hear the odd clack at idle.
The Keihins flat slides do have rollers on the slides.
I do have an annoying creek somewhere though.

davel wrote:

79MKII wrote:

That V&H street system I have really seems to be choking the 1260 motor.

In my experience, the V&H pipe will work well with a competition baffle. Stock baffle chokes the exhaust and no baffle seriously hurts low end and mid range and ears. Competition baffle is the answer.

I do have the comp baffle in there already. It's better but not great. I even drilled it to open it up a bit more. It just seems that the end of the collector is so small even compared to the kerkers. I was always a big fan of the V&H pipe because it has less bends, but the collector size has me wondering. It's the same pipe I had on the bike before but now it's bigger cc, head work, bigger carbs etc... and doesn't seem to work as well.

What is the ID of your collector? my KERker is 2 5/16" id , 2.5 OD.
mine works better with a baffle than without in the low and mid range.
Morriwaki's pipe for the ZRX12 looks to have a 2.5" od collector.

www.moriwaki.co.jp/global/product/ex.php...SAKI&model=ZRX1200#1

i dont seem to see any pipes with big 3" collectors anymore.
This is the size prescibed by a header tuning artical for a 1327cc and 1075cc motor.
This book has tons of good information.

ISBN 0854292756

Performance Tuning in Theory & Practice by A. Graham Bell

--- Header Collector Specs (Conventional Straight Tube) ---
Diameter= 2.188 to 2.438 Tuned Lengths= 13.2 best and also 6.6 or 26.5
--- Header Collector Specs (Megaphone or Diffuser Cone Shape) ---
Diameter= 1.688 taper to 2.688 Megaphone/Diffuser Length= 13.2 inches

Best HP/TQ Tuned Collector Lengths= 13.2 , 26.5 , 53.0 , 105.9 inches long

Worst HP/TQ Loss Collector Lengths= 19.9 , 39.7 , 79.4 , 158.9 inches long

---- Collector's Harmonics (includes Intermediate, Muffler , TailPipe) ----
1st Harmonic = 105.9 inches long ... longest with Mufflers and TailPipes
2nd Harmonic = 53.0 inches long ... longest recommended with Mufflers
3rd Harmonic = 26.5 inches long ... more bottom-end Torque
4th Harmonic = 13.2 inches long ... highly recommended , best Torque Curve
5th Harmonic = 6.6 inches long ... reduced Torque , more top-end HP sometimes
6th Harmonic = 3.3 inches long ... reduced Torque , not recommended

Here's a 1075 motor, 8K Peak HP RPM with 2x

--- Single Primary Pipe Specs --- for 65.599 CID from 6000 to 8500 RPM
1075 cc Diameter= 1.014 to 1.139 (3/8”= .375, 7/16”=.4375”) Length= 22.5 to 25.1 inches long
(1327cc Diameter= 1.153 to 1.278 Length= 22.3 to 24.9 inches long)
1075cc:
--- 2-Step Primary Pipe Specs ---
1st Dia. inches= 1.014 Length= 11.2 to 12.5
2nd Dia. inches= 1.139 Length= 11.2 to 12.5
--- 3-Step Primary Pipe Specs ---
1st Dia. inches= 1.014 Length= 7.5 to 8.4
2nd Dia. inches= 1.139 Length= 7.5 to 8.4
3rd Dia. inches= 1.264 Length= 7.5 to 8.4

--- Header Collector Specs (Conventional Straight Tube) ---
Inside Diameter= 2.201 (Kerker = 2.3125”) Tuned Lengths= 13.2 best and 6.6 or 26.4

--- Header Collector Specs (Megaphone or Diffuser Cone Shape) ---
Diameter= 1.701 taper to 2.201 Megaphone/Diffuser Length= 13.2 inches

-- Total Exhaust System Tuned Lengths (Primary ends to TailPipe end) --
Best HP/TQ Tuned Collector Lengths= 13.2 , 26.4 , 52.9 , 105.7 inches long

Worst HP/TQ Loss Collector Lengths= 19.8 , 39.6 , 79.3 , 158.6 inches long

Note=> measured from where the Primary Pipes end inside the Collector to the point the tailpipe exits into the atmosphere.

Note-> all Pipe Diameters are OD and based-off .0625 inch Pipe thickness

79MKII wrote:

...I do have the comp baffle in there already. It's better but not great. I even drilled it to open it up a bit more....

Was thinking V&H offered two competition baffles in addition to the standard baffle, but below link indicates only the standard plus one competition.

V&H Baffles

Good Luck!

[Click on image to enhance view]

79MKII wrote:

I do have the comp baffle in there already. It's better but not great. I even drilled it to open it up a bit more. It just seems that the end of the collector is so small even compared to the kerkers. [/quote]

what is the ID of a comp baffle?

Can only measure OD's right now, but here's what I have:

V&H = 2.1"
Kerker = 2.5"
Yoshi = 2.9"

The ID of the V&H comp baffle is 1.75"

Well it's nice to have tose 3 pipes at your finger tips.
According to Bells math. the smaller pipe is best. but he also says that is only a starting point. u will need to try all 3 to see wich 1 suites YOU best.
as u change pipes u should only see a movement in the torque curve, up or down 600 rpm or so. larger diam will raise the curve.
if u do try dif 1's, record your results with each 1 and please let us know how it works.
u may even have to change your jetting??
That is the sort of testing i would love to undertake. my problem is the ZRX12 swing arm. it calls for a modified bend.

I agree one hundred percent. If I hadn't of done it to my bike I wouldn't have believed anyone who told me that. I was enjoying riding with the open pipe because of the nice sound and upper end speed and then I put the comp baffle in and woh! What a difference!
davel wrote:

79MKII wrote:

That V&H street system I have really seems to be choking the 1260 motor.

In my experience, the V&H pipe will work well with a competition baffle. Stock baffle chokes the exhaust and no baffle seriously hurts low end and mid range and ears. Competition baffle is the answer.