Dellorto Stage 2 kit from Rock Solid Engines

GoldenMotor.com

ebikeforum_com

New Member
Jul 12, 2010
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California
I am thinking about getting this kit and am just wondering if anybody has any experience with them. Basically what I am looking for is a kit that already has all the performance mods done to it and is as reliable as possible. If anybody has any other suggestions on such a kit please let me know.

Any and all help would be much appreciated.

If you do a google search for "rocksolidengines" you can find the kit I am asking about below. I just can't create a direct link since I am still a new member.

70cc HP Stage 2 Engine: Dellorto type flat slide racing carburettor, Accelerator cable to suite, MSD terminal, lead & boot, Billett Aluminium Performance cylinder head, All bolts are replaced using high tensile Allen key type, Loctite 243 thread locker, Inlet manifold porting, Exhaust porting & exhaust modifications, Carburettor idle screw adjusted, Carburettor fitted to manifold, Clutch adjusted to ensure right setting, Individually stamped identification with engine builder & numbered for ID.

Engine kit: comes complete with

* 415 chain
* Penrite running in oil 200ml
* Chain clip
* Clutch cable
* Aluminium clutch handle with clutch locking pin
* Throttle cable
* Twist grip throttle mechanism with kill switch
* 200ml running in oil
* CDI ignition box
* MSD 8.5mm lead
* MSD 90 degree boot
* MSD triple insulated terminal
* NGK spark plug
* Roller bearing chain tensioner (chrome plate)
* Sprocket wheel installation kit with high tensile Allen key bolts & Nylon lock nut bolts
* Chrome plate 44 tooth rear wheel sprocket
* Silver 2lt fuel tank
* Kartech fuel line
* Fuel pet cock
* Fuel filter with magnetic disk
* Engine mounting brackets including high tensile Allen key bolts & Nylon lock nut bolts
* Dellorto type flat slide carburettor & round air filter
* Y ties with stainless steel locking pins
* Electrical scotch clips
* Wiring crimp connectors
* Chrome plate exhaust
* Copper exhaust gasket
* CNC cut 1.5mm Inlet gasket
* Exhaust mounting bracket
* Large round tube engine adaptor
* Silver chain guard
* Screw tool
* Comprehensive fitting instructions
 
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nogig

New Member
Mar 18, 2010
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south carolina
Its a real good kit, All those mods are what most of us do sans the flat slide carb. They are in australia if I remember right so its kind of an expensive shipping proposition for those of us in the US in my opinion. But yeah the kit is a very good upgrade without having to source a ton of different parts.

Bicycle Engine Kits - Rock Solid Engines
 

ebikeforum_com

New Member
Jul 12, 2010
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0
California
Its a real good kit, All those mods are what most of us do sans the flat slide carb. They are in australia if I remember right so its kind of an expensive shipping proposition for those of us in the US in my opinion. But yeah the kit is a very good upgrade without having to source a ton of different parts.

Bicycle Engine Kits - Rock Solid Engines
Yes, they are in Austrailia. I just checked and the shipping is $222. I just get an email from rock solid and they are working on other shipping options. If anybody is interested in going in on a group buy let me know maybe we can get better pricing and split the shipping costs.

The Stage 2 kit is located here
 
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nogig

New Member
Mar 18, 2010
122
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south carolina
WOW !!!!! 464.00 for that you could my a franco morini or for 375.00 I could build you a comparable motor with 6 month warranty. if interested pm me
 

kalvin1973

New Member
Sep 14, 2011
4
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mississauga,ontario
thank you for that but i want the same rock solid have 70cc hp stage 2 that is so nice look and powefull engine.i ask rock solid they charge me $710 to shipped to canada..that is alot
 

decoherence

New Member
Aug 23, 2010
476
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0
sebring,fl
well that is your options. i'm pretty sure you could get all of that a lot less than 700 by building it yourself.
you can either have them just ship that head from there. or pick up some of the other custom heads that are for sale on this hemisphere.
that zb engine that he just linked to is supposed to be pretty bad a55.
 

richirich

New Member
Aug 16, 2011
297
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Port Angeles, Washington
I also checked out that 70cc motor. the price is high ,but i think its for the whole kit. im thinking about contacting them if they woukd sell motor only. that would probably drop the ship weight in half. 250$ for shipping is outraegous.
Oh well, i guy could dream......
 

kalvin1973

New Member
Sep 14, 2011
4
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0
mississauga,ontario
did you.... i just want the engine only...do you have any connection.. for the same engine must be 70cc stage 2 HP. if you could find me one i buy you a cast of beer that a promiss
 

richirich

New Member
Aug 16, 2011
297
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Port Angeles, Washington
I havent contacted rock solid about it yet, it wouldnt be for a month till i woud have that kind of $ to throw down. But i can tell you this, i have reaserched and researched and have not found anybody in the states yet that would have anything with that close to quality that rocksolid is putting into their motors.
It is a shame, they would really have one **** of a market here.
RIDE ON>>>>>
 

Tohri

New Member
Aug 28, 2010
159
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0
People's Republik of Massachusetts
If you wanted to do up a kit that'd perform like that, ere's your build list:
Start with any chineese 2 stroke kit, 66/70/80/whatever CC.

Throw out the stock chain, head studs, motor mounting studs, stock head, stock acorn nuts, and stock intake if it's cast aluminum.

Purchase hardened studs from SBP, or cut your own from threaded rod. (Note, some of the motors have M8-1.0 thread pitch studs for the bottom end, with M8-1.25 pitch top ends. Whoever designed this will suffer my wrath, as 1.0mm pitch is impossible to find even on Mcmaster.com)

Use 'Heavy' nuts for the head studs, and double nut the motor mounts. Bore out the motor mounts to 8MM if you have the tap, and use the hardened rod for those. I had a rear mount stud shear clean off at the block recently, I had to sharpen a drill specifically to bore it out.

Do NOT use the stock chineese hardware for any load bearing applications. I should not have to make myself clearer.

Purchase the following: https://www.treatland.tv/puch-moped-70cc-hi-compression-head-p/puch-hi-comp-head-70cc-maxi.htm
https://www.treatland.tv/dellorto-SHA-15-15-carburetor-p/dellorto-sha-15.15-lever-carb.htm
Your choice of expansion chamber Exhaust. Or make up a header and use all black exhaust chamber - 28mm.
If your stock intake was cast aluminum, get Dellorto SHA 15.15 W lever Choke and 19MM bushing instead of the treatland dellorto.
https://www.treatland.tv/SHA-15mm-clone-carburetor-p/sha-15mm-clone-cable.htm This carb is still superior to most of the clone carbs out there, the aluminum is nicer and it has a mixture screw. I'll give a more detailed analysis shortly, my moped guru has one I'd like to buy.

Once you have all your treasures, buy a dremel and mcmaster Part number 42955A22. A right angle attachment for your dremel will help tremendously. Drill out the holes on the treatland head to 21/64", and then go to town on the stock china jug. Raise the transfer port ceilings till they're flat with your carbide cutter, and aim the ceilings so they point at your spark plug. Check this with a cut off popsicle stick. You want both incoming charges to collide over the spark plug. The transfers on these kits range from poor and ambigious, to downright useless.

About now you're saying 'But I just want to BUY a motor that will rip as soon as I bolt it on!' It doesn't work like that, at least not till somebody on here buys in 10 or so jugs and ports them out. =P A bigger better carb and pipe won't help you unless your porting is corrected. THAT is the secret sauce nobody will tell you about.

Once your transfers have been corrected, clean up the intake and exhaust ports. The exhaust can be widened a mm or two, but don't get crazy, and hang a ring. And don't raise it at all unless you like having no bottom end power. Same goes for the intake: Raise that port, and bad things happen. A little width will help a bit, but not much over here due to the intakes on these motors being so small. Leave the surfaces rough on the ports, a little turbulance helps flow believe it or not.

IMPORTANT: Chamfer or radius ALL port edges. go over them with a small grinding stone or very lightly with your carbide burr and put a little fillet or chamfer on them, then scrub down the edges with some 800 grit plus sandpaper on a popsicle stick. If you have rubber polishing bits for a dremel, use those here. Remember: only you can prevent hung rings and scraped pistons.

Clean the cylinder VERY well, we don't want granules of aluminum in the motor, and slide it down over the piston. Bring the piston to top dead center, and look in the intake port. See that piston skirt overhanging there? Either cut the piston skirt to match the intake at TDC for more high end RPMs, or use JBweld to correct the intake port shape to conform to the piston skirt (Or a bit below, remember, this is all about timing something that follows sinusodial motion) to bring up low end grunt.

The piston skirt defines the opening and closing of the intake port. Cut the piston skirt to increase the open time (And make the port open sooner/close later) and you'll lose some primary compression. Lower the port ceiling, and open time decreases, the port opens later and closes earlier. Your call.

After you've ripped your motor asunder in this manner, port match your intake and exhaust of choice, make new gaskets all around (Head gasket can survive for now, but making one from copper foil has been phenominal for me.) Lap flat all the mating surfaces of the head, Cylinder, Intake, and exhaust with at Least 600 grit sandpaper, 800-1500-2000 series if you're insane like me. A mirror, windowpane, granite surface block are all good surfaces for this operation.

Balance your crank, or have someone do it for you! Seriously important, even a 'super duper pro screamer race motor' will shake your teeth out if it's not had proper balancing done. There are people who understand it better than I do on this forum, I'm a 'Keep drilling holes near the crank pin till the shaking goes away' brute force approach type of guy. Oh, and stuff the balance pads and hollow crank pin with something like ultra grey to bring your crankcase volume down, and your primary compression up. While you have the cases apart, lap the mating surface where the cylinder meets the cases, and match the cases to the cylinder. You'll thank me later. While you're there, if you have access to a sandblaster, mask off your bearings REALLY well (Or pull them out and re-assemble with press fit loctite) and texture the inside of the crank case. Every little bit helps.

Now you're ready for re-assembly! =D Buy a decent BMX chain, and make sure your front sprocket fits freely. If not, very carefully grind it with your handy dandy dremel so you have good free movement. Replace all the stock gaskets with ones you've made from Felpro (Or your material of choice) All the stock hardware with stuff that won't strip under standard amounts of torque, and install on your bicycle. Usual rules apply there.

With an expansion chamber, decent carb, cool running puch head, BP6HS plug, and premium gas mixed with your favorite synthetic (Or castor) oil, the above modded stock motor will be reliable, consistent, and most of all Powerful. This is the kind of work they do NOT do at the factory so they can sell a motor kit for 200$ and make a profit. Yes, it takes time and patience, skill, and lots of research. Consider what I outlined above a stage 4 or 5 motor kit. =P If we are to use that manner of crude parliance.

...Stage 6 is what I'm going to be experimenting with this winter, and as with everything, I am planning on posting a how-to guide on the theory behind it.

(Addendum: If somebody WANTS, I'll build and sell em a stage 5 motor. But it is not going to be cheap.)
 

richirich

New Member
Aug 16, 2011
297
0
0
Port Angeles, Washington
I can understand what your saying, but it is not true with everyone. I consider myself somewhat mechancaly inclined. I have built a really nice bike. i have gone thru alot of trial and error. I have done all the standard upgrading i could possibly do beside actually taking the case apart and grindind out ports and messing with the piston. I have spent days reading all the posts on this and it is still overwhelming for someone who has never seen it done. the post ive seen on it dont really say what exact motor there are doing it to and everybody seems to have their idea on whats right.
Having a motor with this work already done to it, i would have more confidence in doing my own motors like it. Im kinda looking at it like how many motors and top ends would i go thru before i got it right?
I am thinking this winter when washighton is snowed in ill just buy a few motors and experiment with all the porting and transfer ports and pistons. hopefully i wouldnt screw them all up.
Anyway, just buing a 400$ motor and copying from there seems like an easier solution.
But then again nothing ever seems to be easy...
at least ill have something to do this winter..