How To Build A Fast Elite! Build and Tune info (56k beware)

burnt_toast · Post by **burnt_toast** » Mon Mar 10, 2008 11:41 am

The following thread explains in much detail how I put together my 2001 Honda Elite SR50 which did 35mph stock and turned it into a ministroked 72cc which is capable of 70+mph. This was my winter project and spanned about 5 months, started getting parts in November 07, with most parts sourced I began the build in January 08 and had it together by end of March 08, with tuning still ongoing. This is being stickied for others interested in similar builds to get a good baseline and idea to start from, enjoy!

Here's the latest details on my project. Parts I have lined up listed HERE. I decided that after spending top dollar on almost everything new, using a used $40 82cc Taiwan cylinder wasn't going to cut it.

SO I shelled out big bucks and got a CORSA! (Along with my Ruima Ministroke)

And here's how its coming together:

Look at all that grease and grime lol

Apart and cleaned up

Problem was I had already started cutting the cases for the 82cc kit witch has a much bigger boost port. You can notice in the pics what would need to be taken off, and how I patched it up once the Corsa came in.

Once I cleaned up the gasket material off everything and polished some surfaces I decided to have the cases and new crank put together at a machine shop

Not very pretty from this angle, but looks better from top view

Slightly ported and polished intake

The mighty Corsa, in all its glory! heh

Shiny new Oil Plug goin in

And here's the gaskets I cut out to compensate for the extra stroke, used paper/rubber type material that is supposed to withstand gas and oil. Thickness was 0.8mm per gasket,
stock crank= 41.2mm
ministroker=44.1mm
So I used 4 gaskets total= 3.2mm to compensate, you'll see why..

This is exhaust port clearance with the ministroke and NO extra gaskets, meaning exhaust port would clear, but..

Notice what happens here, piston would hit the head. BUT since exhaust clears means if you raised the head and had enough clearance then 78cc would be possible

This is exhaust port with the 4gaskets installed, exhaust port definitely clears with space left over

The piston now clears too, but displacement is down to ~72cc, which I'm okay with since I dont have extra head gaskets and not something I want to mess with at this time

Installed and cleaned up, head bolts converted to studs with bigger head nuts

Exhaust port view compared to stock, just for kicks. Wonder how it will clear with the PG now that the cyl is raised..

So thats where I'm at right now. I'm gonna be pretty busy with classes this week and I probably wont get to do much more until Spring break, Stay tuned.

Dac · Post by **Dac** » Mon Mar 10, 2008 3:40 pm

so im kinda lost...

So even tho' you went mini stroker, it didn't make one bit of a difference?

But man... Nice Pics! I cant wait to see this bike done!

burnt_toast · Post by **burnt_toast** » Mon Mar 10, 2008 5:35 pm

Dac wrote:so im kinda lost...

So even tho' you went mini stroker, it didn't make one bit of a difference?

But man... Nice Pics! I cant wait to see this bike done!

lol, yes it should make a difference. notice the ministroke takes up more crank volume and has teflon spacers, it should also hold up better than the stock crank.

but displacement wise going from 72cc like with a stock crank, no I didn't go bigger. I could have if I messed with head gaskets and head instead, note the comments.

stillspeeding · Post by **stillspeeding** » Thu Mar 13, 2008 4:50 am

I have a 44.4 mini which is the largest built by qwik-fix, i believe he shaved the piston skirts to clear the crank which is how you make a contessa into a corsa, its a true 76cc.

burnt_toast · Post by **burnt_toast** » Thu Mar 13, 2008 11:27 am

stillspeeding wrote:I have a 44.4 mini which is the largest built by qwik-fix, i believe he shaved the piston skirts to clear the crank which is how you make a contessa into a corsa, its a true 76cc.

I believe that, they probably added head gaskets too. Piston crank clearance is actually one thing I forgot to check, but it seems to feel okay.

burnt_toast · Post by **burnt_toast** » Sun Mar 16, 2008 11:28 pm

Spent about past three days piecing things together, and here is the latest story, with LOTS of pics for your viewing pleasure

Malossi straight cut Primary on clutch drive closeup

Straight cut primary and secondary, torque transfer baby

Engine case mounted. And adjustable throttle cable installed, that was a pita..

Another case shot, note red throttle cable

Extra base gaskets closeup

Boost port view

I cut the spark plug opening larger to accommodate plug socket, since cyl is bigger and raised

PG mockup fitment

PG Long installed with multitude of washers, helps dampen vibrations

Flange View

Trans components re-installed and heavily degreased, decided to stick with stock vari and clutch setup for now, but rollers at 41g down from 51g stock

Stock manifold vs CT chrome mani, wow almost no difference.. hahaha

28mm OKO and Ghetto rigged Dac style filter , atleast until I can find/order a nice UNI

Nice angle of PG, check out the degreased and cherry rear whitey wheel

With everything needed to run installed, I got some 93 premo and premixed with 32:1 using Castrol oil.

Carb settings: 52pilot, 142main which is very rich, but the point I picked to downjet from.

And? She rumbles!

But.. the super rich setting was good enough only to make some noise but no power. At this point it was dark outside and my parents wanted their garage space so till next update, stay tuned.

Dac · Post by **Dac** » Mon Mar 17, 2008 12:18 am

im diggin' it!

lol i like your filter

. Believe it or not, that gave me a good idea for one for my 96 till mine gets in. (i ordered a real one. Well, not stock but a OKO one. )

but man nice bike. What else do you have in mind of this thing? like a full body and all? or are you going to go sleeper? i cant even imagen any more performance parts.

burnt_toast · Post by **burnt_toast** » Mon Mar 17, 2008 1:11 am

I still have a few parts I haven't installed, sitting in closet:
Lightened Keli Pulley and ramp
Daytona adjustable shock
and Low Profile JDM mirrors

For the most part I prefer the sleeper look, all the bling is in the engine heh

There's still a few more things I'd like to get in the future, but key point now will be tuning everything and hoping my extra base gaskets hold up.

itzmepete · Post by **itzmepete** » Mon Mar 17, 2008 2:40 am

PG stack is darn nice, black would be nicer and a sleeper. But then the sound would probably give it away, bummer.

Don't mean to be critical here, just shooting some info. Base gaskets, run down to any small general aviation airport, have them sell you a small piece of 1/8 is 3 mm or .125 thick aluminum, easy to get. I think next size up is .187 3/16 about 4 .5 mm and .250 1/4 inch or 6 mm is too thick. Draw out a template. Drill all the way around it if you don't have a die cutter or if you know someone with a zip saw, ok, better yet, run down to home depot, buy a zip saw, use it, pack it back and return it, they take anything back within 90 days! Just say it did not work right as you expected, TRUST ME...my friend works there. If your like me you will just keep it. Anyway, Zip saw you can cut it out in minutes. Clamp it down, watch fingers! Drilling many little 1/16 holes around the outline takes a while, ok forever, but can be done. Cut insdie first, then outside. Easier with small drill press. Can later use a grinder piece on a drill , again easier on a drill press and give it that pro smooth look, spay it hi temp black engine paint, good to go. Take into consideration the two base gaskets you will need for aluminum thickness. Aluminum comes in so many thicknesses. Ideally, Stainless Steel is better but harder to cut although its thin stuff. Any small aviation shop would give you a small piece or at the most charge you $5 bucks tops. Why do all this work? Sucks going all out as you are doing and having the possibility of a weak link somewhere. The gaskets will probably hold BUT can possibly compress with time, can cause the head torque to slowly decrease to be less than recommended, leaking head gasket, the problems that come with that, air leaks possible head warpage etc.. Can't retorque for fear of maybe bringing down the head and well you get the idea. Indian Head Gasket sealant works great with paper gaskets and metal surfaces that are not under high pressure such as a cylinder head and can be applied with a Q tip. Its a brown stick shelac type sealer. Unlike silicon, cleans off with thinner and doesn't squeeze outside or better yet inside where it can break loose and be eaten.

Did you take into consideration that raising/lowering the cylinder might affect the ports intake exhaust timing? Ignition shouldn't be affected but port timing should.

Yeah my Corsa head shoots the plug at the same wrong angle. I think I will take my head to work, bead blast it and mill my stock head to match my new bore and use it instead, eventually or find another aftermarket head with the correct angle. I don't want to cut my shroud opening. Plug boot is inserted then I adjust the shroud, a pain.

Good choice on keeping the stock Vari, ok, sorry, I couldn't help it! Be interesting when you run it and then run the kelli using same weight and ramp see what preformance diff! Ok, sorry again, no more Vari stuff.

That PG pipe looks really sweet!

tru72 · Post by **tru72** » Mon Mar 17, 2008 4:12 am

make sure you break that bore in "really" good, like 10 gas tanks worth before holding it wide open . Nothing beats a good broken in polini. Unlike the hard breaking in, i wouldnt advise to do it with this cylinder. Those things when they are fresh heat seizes pretty easy . The best ones is the ones that people have used ,they have gone thru many heat cycles and are very stable. When breaking that in make sure you try not to go up hills or put any unnecessary load on it. Also make sure you use a temp gauge, and good synthetic oil like castor. They are killer bores and produce alot of power. Be aware of the mini stroker, they tend to break cranks some times because of the added rpms..
good luck

burnt_toast · Post by **burnt_toast** » Mon Mar 17, 2008 9:47 am

tru72 wrote:make sure you break that bore in "really" good, like 10 gas tanks worth before holding it wide open . Nothing beats a good broken in polini. Unlike the hard breaking in, i wouldnt advise to do it with this cylinder. Those things when they are fresh heat seizes pretty easy . The best ones is the ones that people have used ,they have gone thru many heat cycles and are very stable. When breaking that in make sure you try not to go up hills or put any unnecessary load on it. Also make sure you use a temp gauge, and good synthetic oil like castor. They are killer bores and produce alot of power. Be aware of the mini stroker, they tend to break cranks some times because of the added rpms..
good luck

Wow really.. 10gas tanks worth?? I was just plannin on 100mi of speed up/ slow down riding at a fairly rich setting, you don't think that will be enough? Man I was plannin on hard breaking in too.. Hmm, well I will try to take it easy then for this break-in.

Temp and tach gauge are on the todo list, but will be using an IR hand held one in the meantime. Ministroke has brand new Honda bearings and Seals so I hope it holds up.

burnt_toast · Post by **burnt_toast** » Mon Mar 17, 2008 9:52 am

itzmepete wrote: Did you take into consideration that raising/lowering the cylinder might affect the ports intake exhaust timing? Ignition shouldn't be affected but port timing should.
..
Yeah my Corsa head shoots the plug at the same wrong angle. I think I will take my head to work, bead blast it and mill my stock head to match my new bore and use it instead, eventually or find another aftermarket head with the correct angle. I don't want to cut my shroud opening. Plug boot is inserted then I adjust the shroud, a pain.
..
That PG pipe looks really sweet!

I did actually consider doing something like that, but taking the alum piece and having it cnc milled, however that would end up costing too much.

I didn't technically check the port timing, but you can see what BDC and TDC look like in my first post, after the base gaskets.

And I think dremeling the shroud and using correct head is a bit easier than modifying stock head.

I plan on painting PG flat black, but need the clear coat to burn off first and going to see how it holds up to rust first.

itzmepete · Post by **itzmepete** » Mon Mar 17, 2008 2:50 pm

Yeah, CNC is not cheap. Aviation aluminum is really thin and a zip tool will eat thru it really easy. You need the right router bit. Actially, on a small drill press with the right zip tool, you can grab the piece and manuver it around the bit and get a nice finish, but it is work.

Yeah, milling the stock head is work. I can't help but think the combustion chamber on the stock head might be smaller than the Polini. I am lazy now, but its eating at me. I wanna pull it, do a volume c.c (not comporession) check on both and compare which has less volume hence more compression. I can just use a dremel to mill/smooth down the corner edge on the old head, thats all that really needs to be trimmed as any sharp corners tend to be hot spots in a combustion chamber.

burnt_toast · Post by **burnt_toast** » Fri Mar 28, 2008 1:32 am

Well its been a while since I've updated, so here's the latest most done over spring break:

Keeping stock centerspring and close to stock rollers was a definite NO NO, did 12 different jetting combo's before pin pointing that problem was not in carb, but in trans. At this point I also found a much nicer proper UNI filter albeit .5" smaller than needed ID, mounted it with a coupler and its holding so far. In search of 2" UNI in progress

Next I dropped the weights to 5.3g x6 and it let me get into the powerband from 20-40mph, then would fall flat, due to too fast upshifting as I figured out.

So having a spare 1.5K Kaku spring, I installed that and retuned jetting and here is the current setup:

1500rpm center spring (15% some say)
32g in stock variator
142 main 50 pilot A/F 1.5out
B8HS plug

Low end needs more work (due to stock clutch grab springs/stock clutch and rich a/f and pilot) but once past 20mph.. SHE FFLYYS

Have hit GPS speed of 62.8mph on a short stretch with a bit of WOT, I dont see the needle heh. Temps staying under 350F, using autometer gauge with thermocouple touching cylinder head.

And of course, some update pics. Enjoy

And unfortunately that sweet looking breather filter came off on one of the test runs..

itzmepete · Post by **itzmepete** » Fri Mar 28, 2008 7:04 am

Toast, don't you have 7 to 1 gears on that scoot of yours? My take off is quick like a stock 50cc for the first 3 to 6 feet then it slingshots and you can feel it pull hard thru the fuel guage area where it dissappears. The pull doesn't easy off till the needle is gone.
I'm using the stock 9 grams in the Kelli Vari, 8:44 to 1 final and the Corsa, Polini Belt and a new stock clutch off of a 92 Elite, thats it. I do think my carb runs a hair rich at start out though, but the plug looks great so why mess with it for now. Maybe once its broken in, I'll drill a few extra jets down a few sizes and try it out.
I'm gonna get my GF to speed check me tomorrow, then maybe make a video although all I have is my cell camera and I don't wanna break my butt holding on with one hand, its scary. But maybe she can video it instead on her speedo.
You know if your carb is too big, it will kill your low end torque until the engine reaches speed and can suck it in more. At least that was the case when we did our Mopar V-8's and we didn't have the Cu In, Cam and Compression to deal with a big carb that looked cool. Low gears, as in high speed also did the same for take off. The engine couldn't get the power off cuz the low factory gears held it down. 7 to 1 is kinda steep but your top end speed should be unreal.