SBP 4 Stoke Prototype

Ghost0

Ghost0

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SBP 4 Stroke Prototype

Just thought I would give all the members here a sneak peak at the new 4 Stroke unit. Time to start testing but of course our lovely weather up here in Washington is raining, as usual.
 

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I Like It I Was Thinking About Going To 4 Stroke,on My Next Project. Now You Need To Get A Tuned Pipe For It.that Would Be Sweet.how Much Did It Run You, If You Don't Mind Me Asking?
 
Well if someone would send me one I might.

D4of4,
This is our prototype. We will be testing it over the next month or so and then get it on the market. BTW tuned pipes don't do any good on a 4 stroke.
 
Sweet! If that was my bike I would get that throttle on my left so that I can pull the rope with my right. Of course you can still run it easier on the right and on the left it throttles backwards but on my bike it's way cool and a bit anti theft cause crooks be a bit confused.
Anyway,forget what I just typed. That went together quite well.
 
Hi Everyone,

"BTW tuned pipes don't do any good on a 4 stroke."

You might want to re-think this comment. When I raced 4 strokes on the dirt tracks, exhaust sytems made the difference between winning & losing. The exhaust system on my Ducati single added over 1000 RPMs by using the factory tuned pipe. On my Harley XR750, simply cutting a 45 degree angle at the end of each pipe added 250 RPMs. My Whizzer increased the RPMs by 900 by switching the pipe at Dawson Springs, KY last year.

It makes such a large difference that we are offering a "tuned" flex pipe as an option for the Easy Motorbike kit [4 stroke]. A friend of mine, Ron Dow, had the same concept about pipes until he changed the length & I.D. of the pipe on his Whizzer and reported back to me that it made a difference of 3 MPH on the top end of his Whizzer on his Dyno.

Are "headers" considered tuned pipes? If so, does it make a major difference in HP in race cars?

The pipe included with the current 4 stroke kits is very restrictive [including our kit], and last week one of our dealers changed the exhaust on a small 4 stroke [not our motor] using our drive system and it made enough difference to allow the motor to pull taller gear ratios.

The only difference on my personal EZM motor kit is the drive train & exhaust system, and many that have rode it can testify to the ample power difference. Pulling a ratio of 16.30 X 1, my motor will easily climb to 37 MPH, and leave the stop sign under power [no pedaling needed]. I am not saying the exhaust is the only reason, because our drive system has reduced the "drag", but the exhaust does help.

Have fun,
Quenton
Get YOUR EZmotorbike TODAY!
 
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Hey everyone - I'm pretty darn sure Jim knows exhaust systems can make a difference on ANY IC engine. What he was referring to was the tuned 2 stroke pipe (an expansion chamber) - which indeed will not work on a 4 stroke engine, in particular no exhaust/vacuum scavenging effect......
 
Hi Pablo,

Sounds 100% correct to me, and I am sure "Jim" knows exhaust systems. Sadly when it comes to exhaust systems, many don't have a clue. In fact Whizzer released a muffler insert several years ago and it almost stopped the motor from reving above 5000 RPMs. And from the looks of the current pipe on the 4 stroke 49 CC motors, it appears to be a 2 stroke pipe with different "guts".

Have fun,
Quenton
Get YOUR EZmotorbike TODAY!
 
Yes proper exhaust can make big differences in horse power on any engine, but my point, as Pablo pointed out, there is not such a dramatic performance increase improving the exhaust on a 4 stroke as there is on a 2 stroke. However Q you are correct that the stock one on the 4 strokes is horrible, some backpressure is good on a 2 stroke but horrible on a 4 stroke. So yes there is definitely performance to be gained with a proper exhaust on a 4 stroke.
 
I would love to see a performance exhaust for a Honda 4 stroke. For now, I'm happy using the stock exhaust with a hole drilled next to the outlet.
 
Houghmade: Where exactly did you drill a hole, at the end of the pipe on the bottom of the fat part? And does it help.
 
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