01 elite s sa50 90cc big bore tuning help

[nightstalker]

i have an 01 elite s sa50 just perchased a 90cc bbk off ebay with 9:1 gears the add said it would work with stock carb and pipe, the kit came with a 100 main jet everything installed the scooter wont go over 15mph

removed the stock air box, variator backing plate, and drilled out the washer in the pipe, and messed around with all the tuning options on my stock carb wich are basicaly none

my question is, is this setup even going to work with the stock carb and pipe? or am i just wasting my time?

any and all help would be appreciated if anyone has a simmilar setup or knows my next step please help me out i need this thing back on the road!

[Wheelman-111]

Greetings:

Quoth NightStalker:

i have an 01 elite s sa50 just perchased a 90cc bbk off ebay with 9:1 gears the add said it would work with stock carb and pipe, the kit came with a 100 main jet everything installed the scooter wont go over 15mph

(Emphasis Added). But was everything installed Correctly? What was the static compression after you bolted it up? Did you make any attempt at break-in? Did the kit come with a 50mm cylinder head? What if anything did you do to increase the lube rate for the 80% displacement increase? There's just not a lot to go on here.

removed the stock air box, variator backing plate, and drilled out the washer in the pipe, and messed around with all the tuning options on my stock carb wich are basicaly none

The Stock Carb needs some kind of attention when you yank off that airbox. Put it back and see if it's better. Slapping in a 100 Main may or may not meet the needs of the bigger displacement you created. Temp gauge or at least a plug read might be revealing.

my question is, is this setup even going to work with the stock carb and pipe? or am i just wasting my time?

While it's not going to give you the absolute Maximum your "90cc" setup can produce, it should be possible at least to exceed Stock performance. It's all in the tuning.

any and all help would be appreciated if anyone has a simmilar setup or knows my next step please help me out i need this thing back on the road!

There's a lot of information in the Tech sections. The key to getting help from Those Who Have Gone Before is to demonstrate a little initiative and having read a little in there will gain you more sympathy if not Respect. What specific "90cc" setup did you purchase. FYI lots of vendors can't do Math. What they're calling "90cc" is most likely 82 if you bought a 50mm cylinder, for example. 90cc requires a 51 PLUS a Ministroke 44.1 crank.

CC Displacement equals pi times the cm. Radius of the bore squared times the cm. of the stroke.

D = pi R(Squared) x Stroke

2.5 x 2.5 x 3.1416(pi) x 4.14 = 81.2cc

[veedubh20]

my question is, is this setup even going to work with the stock carb and pipe? or am i just wasting my time?


yes the stock carb waste of time!
the block need to be split the case to match boost port.
should have gone another route.. get a polini contesta bore..is bolt on, no case split need!

on most taiwan bore over 50mm bore, must split the case, need work on boost port/intake port. Or you cant go back to 72cc ,need to find another stock block..

[nightstalker]

ya wheelman comps good at about 125, big bore kit is almost broke in and yes done right, still running a 35:1 mix along with split cable oil pump. bbk was from chopchop on ebay, cylinder, head, studs, gaskets, 9:1 gears, 100 main jet. sorry about the lack of info im in the garage messing with it now.

i put the airbox on and the bike barly does 10mph, did a plug check seems to be running rich doesnt make any sence to me

ive been in and out of the tech foums over the past few days trying to find some answers before posting my stupid noob questions but figured id give it a shot thanks for the help guys

[swimmingfree]

do a compression test ... 35/1 pulse the oil pump you running way to munch oil i wood let up on the gas oil mix some and get a new plug...
swimmingfree

[nightstalker]

do a compression test ... 35/1 pulse the oil pump you running way to munch oil i wood let up on the gas oil mix some and get a new plug...
swimmingfree

compressions good ill try a 40:1 mix with new plug im still at the tail end of break in thats why im running a little more oil

[Wheelman-111]

Greetings:

35 or even 40:1 PLUS the pump is WAAAYYY too much oil. Yes it's rich in oil and that would account for the wet-looking plug, but it's going to be 2 or 3 jet sizes too lean on the fuel/AIR ratio, because that much oil leaves too little fuel combining with your unobstructed intake air. I'd be surprised if it didn't seize. Maybe the only thing that saved it is it couldn't rev high enough to burn itself out. 35 or 32:1 is plenty but the pump's added input puts you at something like 20:1. Maximum premix is 70:1 if you insist on keeping the pump. Better yet, buy a plug for the pump socket and run 32:1. Don't forget to reinstall the airbox with a properly saturated NEW filter element. Yankin' that thing off does little for performance, and completely trashes the low-speed mixture and the transition from low- to high-RPM running.

I disagree with VeeDubh, respectfully. The stock carb/pipe CAN be made to work acceptably if not with real good performance. Matching the boost port is necessary if you want it to Be All That It Can Be, but lots of Posters don't bother with it for a Daily Rider, apparently without problems.

[nightstalker]

Greetings:

35 or even 40:1 PLUS the pump is WAAAYYY too much oil. Yes it's rich in oil and that would account for the wet-looking plug, but it's going to be 2 or 3 jet sizes too lean on the fuel/AIR ratio, because that much oil leaves too little fuel combining with your unobstructed intake air. I'd be surprised if it didn't seize. Maybe the only thing that saved it is it couldn't rev high enough to burn itself out. 35 or 32:1 is plenty but the pump's added input puts you at something like 20:1. Maximum premix is 70:1 if you insist on keeping the pump. Better yet, buy a plug for the pump socket and run 32:1. Don't forget to reinstall the airbox with a properly saturated NEW filter element. Yankin' that thing off does little for performance, and completely trashes the low-speed mixture and the transition from low- to high-RPM running.

I disagree with VeeDubh, respectfully. The stock carb/pipe CAN be made to work acceptably if not with real good performance. Matching the boost port is necessary if you want it to Be All That It Can Be, but lots of Posters don't bother with it for a Daily Rider, apparently without problems.

ya i wasnt realy sure what the pump put out, thanks for the input ill back off on the premix, but i think i found the major issue i was getting angry so i cut the end off the stock pipe it was almost completely plugged up and full of oil put it back on now its doing about 40mph and getting there fast adjusted the primary and moved the needle up one notch for midrange enrichmenti still think im going to go up one main jet but the 100 main is the only size i have

[Wheelman-111]

Greetings:

In that case, 40 MPH is already faster than a healthy Stock engine could go. If this is with 9:1 gears you might see 50 or more with good tuning. Consider another plug chop and inspection, or better yet install a CHT gauge to read what's happening in real time. The 100 is big but not huge for 80+cc, and there's still a chance of overheating. Particular caution is indicated when coasting down from a high-speed run. The tiny Pilot will struggle to keep enough fuel going down to cool the engine.

Max Pump Output for the S pump is about 70:1 or 1.5% so maybe you're not as thick on oil as I first apprehended. Adding tank 70:1 premix makes for about 3% or 33:1 right in the ballpark.

[nightstalker]

Greetings:

In that case, 40 MPH is already faster than a healthy Stock engine could go. If this is with 9:1 gears you might see 50 or more with good tuning. Consider another plug chop and inspection, or better yet install a CHT gauge to read what's happening in real time. The 100 is big but not huge for 80+cc, and there's still a chance of overheating. Particular caution is indicated when coasting down from a high-speed run. The tiny Pilot will struggle to keep enough fuel going down to cool the engine.

Max Pump Output for the S pump is about 70:1 or 1.5% so maybe you're not as thick on oil as I first apprehended. Adding tank 70:1 premix makes for about 3% or 33:1 right in the ballpark.

thanks for the info Wheelman! no the 40mph is everything but the 9:1 gears (is there any how to's on installing them on here? ive looked everywere in the search box) i did a plug chop at idle midrange and wot, and i do need a little bigger main jet for sure. does anyone sell different pilot jets for the stock carb? and were would i get a CHT gauge from? real time monitoring would be nice.

[Wheelman-111]

Greetings:

Just go to Technical Documents and scan the titles for Gears. If you have a big-* press, the biggest gear (#4) comes off the axle and the slightly smaller Ruima gear goes on. Then swap the countershaft for the bigger Ruima item. Button up, paying attention to the countershaft clearance. You may need to sand down the plastic countershaft shim washer to half-thickness or it will bind when you tighten the cover. Add 3 oz/90cc of leftover 10W-30 and you're done.

Search for vendor DayWot on eBay. He carries the stock carb jets in a Daytona set up to 105. I would not be surprised if you needed a bit bigger still. If you do, indexing drills from Harbor Freight is your only option if you wish to stick with the stock carb. Find the drill that just barely fits the 105 and drill a size bigger. An electonic caliper can help you know exactly what mm size you're drilling. 1.1mm = 110 in Keihin-speak.

As for CHTs, eBay again if you can find a Vapor electronic gauge. You'll need the short wire extension to reach the spark plug, under which you replace the plug's crush washer with the copper 14mm gauge sender.

[nightstalker]

This thing is still running lean got a 105 main jet stock carb box needle raised all the way i tried a 110 main and it doesnt run at all, the bike also runs great for the first 5 minutes or untill it warms up then after that it feels like the motors realy struggling to turn. I know this isnt the right setup to be running a stock carb with a bbk but im going to try to make it work