4 stroke with sickbikeparts jackshaft

toker_ace

Member
Oct 15, 2008
476
1
18
alabama
Anyone have any cvlt1feedback on this setup. I've had a 2stroke with SBP jackshaft but would like to try the 4 stroke set up. Any advise would be great. toker_ace brnot
 

KCvale

Well-Known Member
Feb 28, 2010
3,967
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Phoenix,AZ
Love 'em, built a handful, this one just left the shop this morning.

Big Red II.
Macargi Pantera 7S with aftermarket front shock fork and 3-speed internal rear hub gearing.
$350 gasbike 49cc HS 152F 4-stroke and 4G transfer case.
$200 SickBikeParts 4-stroke shift kit.





I did the gasbike engine kit opposed to just an engine, tranny and basic parts like gas tank and throttle because I can use all the let over parts that the SBP 4-stroke shift kit replaces later so price them separate from the JS kit for just what you need if you don't want extra parts, the thing is when I shopped I only saved like $25 from just getting a whole direct drive 4-stroke kit and I got alot of left over parts for dirt cheap opposed to piece-mealing the part buys.

Many build options but a nice system indeed.
 

toker_ace

Member
Oct 15, 2008
476
1
18
alabama
I guess I am going to take your advise. I have built 20-30 2 strokes over the years but know nothing about the 4 strokes. I love my 2 stroke with SBP jackshaft and three speed sram hub. It appears the 4 strokes are alot faster than the 2 strokes? Jeff
 

KCvale

Well-Known Member
Feb 28, 2010
3,967
51
48
Phoenix,AZ
I guess I am going to take your advise. I have built 20-30 2 strokes over the years but know nothing about the 4 strokes. I love my 2 stroke with SBP jackshaft and three speed sram hub. It appears the 4 strokes are alot faster than the 2 strokes? Jeff
Speed is an irreverent measurement for the most part from my personal rides around the same test area with multiple configurations of the same bike base.

A 49cc 4-stroke 3-speed will run with a 66cc direct drive in every way even off the line.
Even a 49cc DD will run with a 66cc DD on the open road once you get it wound up but unless you pedal to help a bunch from the line the 66cc 2-stroke will kick it's butt in a 1/4 mile every time.

Of course a 48cc 2-stroke can't compete with a 49cc 4-stroke in any way stock but there are many options to make a 2-stroke actually perform more like a 4-stroke which tilts the odds as few thing are available to help that 4-stroke short of some sort of turbo/super charger I have yet to see beside the same carb/exhaust stuff.
 

buck0

New Member
Apr 24, 2011
376
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Orange County, Ca
I have one of the SBP's jackshaft setup on my motorized bicycle. It was used with a 212cc preddy & now a GX120. Theres about 1 dozen of races with SBP's jackshaft mount, I had never had a problem with it.

 
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MotoMagz

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Aug 2, 2010
1,704
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Michigan
I guess I am going to take your advise. I have built 20-30 2 strokes over the years but know nothing about the 4 strokes. I love my 2 stroke with SBP jackshaft and three speed sram hub. It appears the 4 strokes are alot faster than the 2 strokes? Jeff
If you are going to a 4 stroke with a shift kit I would not go lower than the 79cc...I have ran all the smaller 4 stroke 99cc and less.my favorite is the lifan 98cc with shift kit parts.tons of torque in all 5 gears just pulls..You have built plenty of 2 strokes so go for it you will love it.Nothing wrong with.a.49cc but you will just want.to move up in cc's real fast
 
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KCvale

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Feb 28, 2010
3,967
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Phoenix,AZ
If you are going to a 4 stroke with a shift kit I would not go lower than the 79cc...I have ran all the smaller 4 stroke 99cc and less.my favorite is the lifan 98cc with shift kit parts.tons of torque in all 5 gears just pulls..You have built plenty of 2 strokes so go for it you will love it.Nothing wrong with.a.49cc but you will just want.to move up in cc's real fast
I agree depending on your legal situation and willingness to gamble with your states laws and enforcement of them not just by the cops but the courts.

If your legal situation is such that most any run in with the law would be a bad thing stick with what works best for your needs and budget as there are many legal options, if it's not an issue then power on!

I am all for bigger and better and really liked the HF 79cc Pred direct drive I built and think it would be an awesome 3-speed internal shifter maybe even for the racers.

Speaking of racing I would be right there with you guys if my body could but all that stupid body damage I did at my peak is back to haunt me on a 24/7 basis so I no longer have the skills for racing.

HOWEVER, my very athletic 'no fear' 24 year old unemployed son will be moving into my home/shop mid next year.

I may not be able to ride them, but I am ready to make a race bike and coach my son how to ride it if he wants to have some fun and make his dad smile ;-}
 

captzuzu

Member
Jan 29, 2013
54
0
6
New Mexico
the jack shaft looks easier to put on a bike then the kit .
Do you have any problems with the foot pegs grabbing with the engine and spinning your feet?
and would this be a easy why to mount on a 29" Genesis Astra Cruiser 7 speed?
 
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KCvale

Well-Known Member
Feb 28, 2010
3,967
51
48
Phoenix,AZ
the jack shaft looks easier to put on a bike then the kit .
Do you have any problems with the foot pegs grabbing with the engine and spinning your feet?
and would this be a easy why to mount on a 29" Genesis Astra Cruiser 7 speed?
Since you have more than 36 spokes using the drive side with a 7-speed is a natural for using a shift kit so using the existing bike drive train works best but is far from 'easy', there is no room for slop in anything transferring big power rotational force.

Do it right and a good KMC or Diamond 7-speed chain and you should be good and ya, gears change everything ;-}
 

waynesdata

Active Member
Jul 10, 2017
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If you are going to a 4 stroke with a shift kit I would not go lower than the 79cc...I have ran all the smaller 4 stroke 99cc and less.my favorite is the lifan 98cc with shift kit parts.tons of torque in all 5 gears just pulls..You have built plenty of 2 strokes so go for it you will love it.Nothing wrong with.a.49cc but you will just want.to move up in cc's real fast
79cc shift kit build examples are had to come by. Any advice would be welcome.
 

MotoMagz

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Aug 2, 2010
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Mags that's still a great build, doing it right stays cool!

Rick C.
Yep those were oldies but goodies. I like the shifter bikes ...they are fun... but can be a little more work setting up. Also adjusting chains till they are done stretching is not that big of a deal,as long as leave room for adjustments.
 
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indian22

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Dec 31, 2014
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Yep those were oldies but goodies. I like the shifter bikes ...they are fun... but can be a little more work setting up. Also adjusting chains till they are done stretching is not that big of a deal,as long as leave room for adjustments.
Significant details Mags. One off builds aren't in the same universe as kit bike builds...lots of work involved to get them right and most guys don't have the experience or patience to get it right. To top it off you have to spend money for parts that usually require modifications to make them work & have the experience and patience to do it. Always leaving room for adjustments, knowing where to leave room requires.... you got it, experience, patience coupled with foresight.

I always have a wry grin for those who whine when all does not go their way, always complaining about the crappy little import engines, sorry service, delivery, high prices and how it's always everybody else's fault...but never suspect that what is really wrong is that they lack experience and patience in dealing with any of life's problems and with relations dealing with others. Though serious it's also quite humorous and to be expected in most others, but should never accepted as rational behavior in our own lives.

Keep building them good Mags. It's a proper example for us all!

Rick C.
 
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waynesdata

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Jul 10, 2017
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I can not seem to track down the correct engine.

The homedepot site has.

Internet #203281925
Model # LF152F-3Q


This may or may not be the correct engine.
 
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MotoMagz

Well-Known Member
Aug 2, 2010
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Michigan
you are going to have to find Db30 Doodle big mini bike engine. They have been replaced by the ohv. Look on Craigslist usually $50
 
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