Skeptics Review of SBP Tuned Pipe

Well... I finally went for it. The famous tuned pipe kit. I promised I'd never spend more for a hop-up than for a new motor. But it was highly recommended by a couple individuals here whose opinions I respect and only $1 over my limit sooooo..... turned out to be well worth the investment.

The install took less than a half hour with a Zoom 67cc slant on one of my Magna Glacier Point bikes even encountering a couple small issues.

The first was holes on the flange were too small for standard HT exhaust studs. Only took a minute with a hand drill to fix that. Might suggest doing that a service to customers or at least mentioning in the manual. At that point I noticed a defect in the flange surface that might cause leakage (see pic). SBP promptly responded to email with suggestion to machine the surface (yeah right!) or send it back for replacement (yeah right!). I decided to simply plow ahead and see if and how bad it might leak.

After a few minutes of fitting and twisting it became apparent the stock mounting hanger was not going to allow use of my regular kickstand. The manual mentions switching to a different type kickstand. Not an option for me. So out with the kit hanger and in with some galvanized baling wire(see pic).

Positioning the pipe is a little tricky due to clearance issues between front tire, left and right pedals, and rear tire. It also initially wanted to direct exhaust onto the rear rim. A few minutes of twisting and re-aiming came up with a reasonable compromise. Cutting an inch or so off the copper tube solved front tire clearance. Bending the pipes original pocket bike mounting bracket out of the way helped with right pedal contact. It still hits occasionally so I'll probably cut it off completely at some point.

Next problem was the hose clamps are too small. They were both the same size and barely fit over the small end of the silicone tube and not even close to fitting over the fat part. Fortunately I had one of those Harbor Freight assortments and the biggest ones fit. Now we're ready to go!

It was immediately apparent more low end power was available. However the motor ran out of poop and made that "too lean" sound at WOT. And I noticed full choke don't stop the motor any more which is the only way I ever shut down. Needle clip down one notch fixed the choke. Replacing my "wide open filter" (see pic) with the stock air filter cover (see pic) took care of the WOT problem. I may investigate opening up the jet from it's current .028" and taking the stock filter off again later.

Once more with feeling! Even before getting to "dynamometer hill" the increase in low end torque was obvious. Even with the 36t sprocket ($12 BGF) it was now possible to get rolling w/o pedalling and took much less time to get up to speed. Evident beyond the realm of placebo effect. Prior to the install I did a test run up dyno-hill at the expected 23mph. Now it zipped up at 27-28mph. The GPS don't lie.

Noise was significantly louder than stock. Part of this may be due to leakage caused by the flange defect but I suspect SBP sells that lawn mower muffler option for a reason. After the test runs I put on the smaller silicone tubes but no real change in sound. Like mentioned by others it now has that "dirt bike" sound specially when throttling down. No room to stick a muffler on the end because of kickstand clearance but not as bad as a stock exhaust w/holes.

IMO only room for kit improvement might be bigger hose clamps and mentioning undersized flange holes or even drilling them out. Maybe remove the original pocket bike mount too. Easy for a machine shop. Maybe others don't have problems here.

I'm not sure how much of the power increase is due to the leak and how much due to the tuned pipe. In any case well worth the $78 in terms of engineering and materials. I bought the same exhaust w/o fititngs from another vendor last year for about half that but, after assessing effort needed to adapt to a HT, put it on the shelf. A wise move considering how easy it was to intall the SBP kit. Definitely a keeper.

Attached Thumbnails

     

Not positive but.... I think you should have two more pieces of silicone tubing around the connections on the copper piece. One on each joint... that (they) don't require clamps. Are your CDI wires resting on the pipe?

__________________
You do not need a parachute to skydive.
You only need a parachute to skydive twice.

wow,
that thing is lowwww....

__________________
My Production Bobber Build Up
'BrettMavriK
"Everything Is Possible...If You Can See Beyond The Invisible"

I just posted this elsewhere but I thought you may be interested in the low cost yet effective and easily adjustable rear mount I came up with, so I hope you don't mind if I go ahead and quote myself lol;

The length of the header (and that copper straight bit) allows for some tuning of the pipe, I've not messed around w/that other than trimming the copper one just to get it to fit - but I'm quite happy with the response it has now.

I had the same problem with the second hose clamp over the large end of the blue tubing, a shame really because they're quite nice clamps... I did manage to get it to fit with some soapy water and frustration, but I'll weld that section at some point anyway.

Much as they're handy, I've too many blasted hose clamps on my bike already


edit: did you remember to make the center hole in the gasket larger? It's quite a bit smaller than both the exhaust port and the manifold, a somewhat serious restriction of flow, I found I made the hole about 30% larger than stock... (oval instead of perfectly round)

What I'm really lovin' is the duct tape on the engine!

__________________
For engine kits & bike service in Los Angeles, visit us at- www.VeniceMotorBikes.com

On mine I found after a while leaving the springs to hold the top assembly had allowed it to vibrate to much and start leaking. To fix that I used plumbers tape to attach the header to the the frame. I also used rtv on the connections, the main one I found to leak is where there is no silicon coupler. The copper coupler that attaches to the part that mounts to the motor, that's where most of my sound was coming from. Once it's all sealed up the sound level goes way down and you can hear it from the rear of the exhaust instead of from the front.

Also you could try sweeping up the rear of your pipe, that should give you some clearance, so you can go over curbs with out dragging your pipe. The plumbers tape will work well for securing the rest of your pipe as well.

P.S. Barely I like the hose extension. I used a copper 45 on mine to aim it away from my bike. But that looks much cleaner, I may have to try that.

__________________
Sun Tzu: To secure ourselves against defeat lies in our own hands, but the opportunity of defeating the enemy is provided by the enemy himself.

Yeah Shadeslay, I just stuck it on there to see how it would look and it happened to fit perfectly! So naturally I had to ride around w/it


xlite,
Hmm, due to Venice's duct tape comment I took another look... what is that doing for ya? o_O

BTW, ya might wanna flip the manifold plate around so the loop for the springs is underneath, making the springs wrap around the pipe. This provides a more uniform pressure and holds everything together better.

You defo wanna get both springs on there, they're all that are holding the pipe together. Those springs are so prone to breaking from vibration and heat combined with time that they are usually backed up with a safety-wire tether (something I've been too lazy to attend to lol).

Having a second one reduces the stress and provides a "second chance" should the other fail. I really don't wanna run over my exhaust system at any speed

Thanks for the honest review. Sorry about the defective header. We can replace it for you, don't know what else we can do about that. We have not heard of the header not fitting the studs though. We will look into that. As far as the hose clamps they were not intended to go over the enlarged section of the pipe but on either side. I guess we should clarify that in the instructions. Again thanks for the feedback. We are constantly working to improve our products but without feedback we don't know what we need to do.

__________________
Design is easy, execution the hard part.
www.sickbikeparts.com

Some engines have a wider exhaust bolt spacing.

__________________
My Production Bobber Build Up
'BrettMavriK
"Everything Is Possible...If You Can See Beyond The Invisible"

As mentioned in my post the small silicone tubes were installed after test runs. Made no immediate difference.

Not obvious from the photo but the wires are actually 2" or so away from the pipe which is in same position as the stock exhaust was. I put thousands of miles a year on these bikes... believe you me... problems like that got ironed out some time ago.