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Post by larry001964 on Sept 19, 2011 8:51:44 GMT -5
As Some of you may know, my scooter has died... Granted I was really pushing it hard to get a job and driving it far beyond its design limits.. I was driving up to 80 miles a day and with a little over 4500 miles she failed.. It gave its life that I may work. I got the job :-)
I dont believe the 72 BBK caused the problem.. It did I believe accelerate the problem.. The long distance driving I've been doing combined with the cheaper metal used in Chinese manufacturing process turned my crank bearings to mush and the rod is knocking on the crankshaft..
So the next stage is a rebuild, Im going to make it stronger and faster, and will be posting here as to componets im using, where I got them and include pictures and in some cases even video of the rebuild process..
I will be using the Hoca Stroker crank, and combining it with the NCY 83cc BBK... All the components im using are Taiwanese, and built with much better quality than the original, this should withstand the driving im doing...
Since many here and expressed an interest in the stroker crank I will document the rebuild here in hopes of answering questions others may have.. Wish me Luck :-)
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Post by Pony66 on Sept 19, 2011 8:54:50 GMT -5
Good Luck to you. I look foward to reading about your build.
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Post by Scooter Boy on Sept 21, 2011 23:04:36 GMT -5
Larry,
Good Luck on your rebuild.
I know you can bring the Old Scooter back to life!
It will carry you proud once again.
Please post all the details you can.
Hope you can join us on a Sunday ride again, someday.
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Post by skuttadawg on Sept 21, 2011 23:46:46 GMT -5
I too had cracked China pistons but so far Air Sal 82cc BBK seems to be a winner . I was thinking about making my lil scooter a sleeper that can outrun a 150 . I have looked all over to try to find out how much more displacement the stroker crank adds . Longer stroke means more torque . I think you may need to add extra base gasket or shim for clearance issue so do homework prior to build . I have not used NCY parts but I read they are way better than China ones . I could not find a BBK with a forged piston and wondered if a XR80 piston would fit since www.wiseco.com makes forged billet pistons but 130.00 yikes |
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Post by larry001964 on Sept 22, 2011 11:17:59 GMT -5
Special Thanks to the following people and companies involved in this rebuild. Jeremy Hall "Enviormoto" For consulting time, stocking good quality parts PartsForScooters. Stroker Crankshaft, free shipping, John at Adventurous Scooters. Consulting, and stocking parts.. NAPA Machine shop, Logansport. Pressing old oil pump gear on new crankshaft. Jerry at 8 and Up Mobile Auto Repair, My neighbor. ( Use of his impact ) My mother and brother for hauling my butt back and forth to work while I fixed this little scooter. September 22, today I purchased the Stroker crank and flywheel puller from Partsforscooter.com. Total amount was 212.00 including shipping, will post again when it arrives. Next week will be Enviormoto for the NCY 83cc BBK kit, A9 cam, Big valve head, timing chain, oil seals, oil pump, and gasket kit.... This is a total build out. From what I've seen on 49cc.com this will be about 86.39cc's when completed. That should be enough power for the driving I'm doing. Also thinking of getting 6 gram Dr. Pulley Sliders Here's the cc displacement chart on 49ccscoot for the stroker crankshaft 49ccscoot.proboards.com/index.cgi?board=4perfrom&action=display&thread=2608Septerber 14, After thinking about what Jeremy told me, combined with what parts I have seen on Enviormoto's website and Parts for Scooters and 49cc.com. A build came into my head "Part's For Scooters" has a stroker crank, Not much is known about them, not to many have actually done this kind of build. However I believe I have the experience, and resources to actually make this happen, Even though they make a stroker crankshaft no difinitive kits or builds are out there with them, and there is much speculation surronding using them from timing chain to spacers.... Hummmmmm makes me think... Any way here is the build that came into my head. Hoca Stroker crankshaft, NYC 85cc BBK, NCY High performance cam, NCY BB 50mm head, free flow stainless exhaust ( resist corrosion from winter ) and perhaps upping the finial drive a tooth or two, sliders. Perhaps once I have a smooth running scooter, all of this can be but into a kit... If nothing else others will know it will work how much it will cost, other specifics.. |
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Post by skuttadawg on Sept 23, 2011 0:54:44 GMT -5
So 86.39 cc with a 72cc BBK ? Please post if it has more torque
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Post by mainepeace on Sept 23, 2011 1:22:21 GMT -5
Sure, displacement may only increase 3cc but the mechanical advantage would also increase as you now have a slightly longer lever, so more torque.
Greg
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Post by larry001964 on Sept 23, 2011 9:40:40 GMT -5
So 86.39 cc with a 72cc BBK ? Please post if it has more torque Hi skuttadawg not a 72cc but an 83cc BBK |
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Post by larry001964 on Oct 12, 2011 9:45:32 GMT -5
September 22, today I purchased the Hoca Stroker crankshaft and flywheel puller from Partsforscooter.com. Total amount was 212.00 including shipping, will post again when it arrives. Next week will be Enviormoto for the NCY 85 BBK kit, timing chain, NCY Hi Performance cam, NCY Big valve head, oil seals, and gasket kit.... This is a total build out from what I've seen on 49cc.com my engine will be about 93.44 cc's when completed. That should be enough power, and combined with the stroker crank I'm hoping the greater mechanical leverage will actually lessen the stresses, on the rod or at the very least, equal the stresses to the same levels as before. because I'm upping the power with a bigger BBK. I'm not totally convinced that an offset of only 1.3 mm On the stroker crank compared to a stock crank will do much but we will see. September 27, Today the Hoca crankshaft arrived, UPS delivered it to the wrong address. I can't imagine how they can make such a mistake, the Partsforscooters has the correct address on the package, and the address UPS delivered to is completely different. Fulton has a population of about 30 so where it was delivered the people knew us and brought the package to us... Thank god for honest people.. She said they just dropped it off didn't wait for anybody to even come to the door. UPS GET IT RIGHT, I would have given you hell had I not gotten a 212 dollar package... Thursday I plan on ordering the rest of my parts from Enviormoto, Jeremy normally uses USPS. that means ill get a slip of paper in my P.O Box and ill have to go to the post office counter and sign for the packages. Over all that's much better than having my stuff delivered to the wrong address.   October 4, Today I broke the flywheel puller I bought from scooters Plus, the T-handle part. I was hitting the handle pretty hard with a hammer trying to break loose the flywheel and instead of the flywheel coming off the flywheel puller broke. The important part is still intact so ill get a steel bolt and put in it and use an impact... Hopefully that will break loose the flywheel.. Can't do much with it until that flywheel is off.. Also tried to order my parts from Enviormoto, the Ecrator account he uses for credit card payments is blocked by the stupid library and I didn't have my Paypal account updated with my correct address or phone.   October 5, I finally got Paypal updated today with the correct address and phone number.. What a pain that was, but it's done now so tomorrow I should be able to start ordering the rest of the parts.. Wish me luck.. I need to also note that the library also has Photobucket and most other similar websites blocked, I may have to just get my own internet and laptop again so I can properly post pictures and video of this rebuild, I know many here are curious as to the stroker crank and have questions, seems no better time to answer them then someone in my position needing more speed and power. But working around the library restrictions is really a pain. Even utube is blocked, my god that system admin is silly. He don't understand what he's doing so instead of learning the proper protocols and ports to deal with he just hits the problems with a hammer and blocks all... Stupid... Special note I learned we lost Bluefont, I was late in learning this as I guess we lost him some months ago around July, I em truly saddened by this I was really looking forward to his comments on this build, and miss in general posting with him, to his family they have my sincerest condolences.. He is missed.. October 6, Finally purchased the NCY 85 BBK, and High performance cam shaft, just a few more parts to go, but with these parts I can do some test fittings and see how things will line up and fit together, and make if necessary make adjustments or machine adjustments accordingly.    Jerry my next door neighbor and I got the flywheel off today minuets before I had to leave for work, Jerry has a much more powerful impact and after I got the new bolt for the flywheel puller and it popped right off, Now I can get into that engine and see all the damage and begin the repair.. Now comes the fun :-). Ill be a dry fitting to see the difference between the stroker crank and the stock, Ill include pictures of this so all here may see as well..   October 11, Took my engine to the carwash today, wanted to clean it but more importantly I needed to blow out all the metal shavings in the engine. My bearing on my old crank it seems were not mush, but the rod was definitely knocking leaving metal shavings that needed to come out.. And today I also bought a digital Micrometer from home Depot, now I have a means of getting exact measurements, cost 37 dollars,  |
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Post by Pony66 on Oct 12, 2011 10:03:25 GMT -5
Hi Larry, if you want to get real accurate measuring your piston clearance, get some Plastiguage. Its pretty cheap. You just put a strip on the piston, turn the engine and measure the squish on the Plastiguage chart.
Cometic can make any head gasket you need. They are multilayer steel and you can get any thickness. I had some made for one of my Subarus. I should have posted before you resolved the clearance issue.
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Post by qwertydude on Oct 12, 2011 15:53:46 GMT -5
I too have a hard commute and with larry's experience here I don't believe BBK's are entirely without consequence. Mine only lasted about 10,000 miles before I had the same problem, connecting rod knocking on the crankshaft. I previously thought it was the crank bearings but after ripping the engine apart last month it was connecting rod bearing.
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Post by freedomscoot on Oct 12, 2011 23:06:36 GMT -5
I too have a hard commute and with larry's experience here I don't believe BBK's are entirely without consequence. Mine only lasted about 10,000 miles before I had the same problem, connecting rod knocking on the crankshaft. I previously thought it was the crank bearings but after ripping the engine apart last month it was connecting rod bearing. I'd say 10K miles on a tiny engine running between 40-50MPH is pretty darn good! |
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Post by qwertydude on Oct 13, 2011 2:15:06 GMT -5
On my Honda Metropolitan I sold it at 15,000 miles and the thing didn't even need a valve adjustment yet, still ran like new.
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Post by Scooter Boy on Oct 18, 2011 0:40:54 GMT -5
Larry,
Sounds like you got it all figured out.
I'm glad to hear it's all going together OK for you.
I hope you can soon be riding again.
I can't wait to hear your engine roar.
Good Luck & keep us posted.
We all know a 150cc would be cheaper but you wouldn't have half the fun!
John
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Post by mykul on Oct 18, 2011 9:34:54 GMT -5
I'm dying to hear how this works out! I remember many years ago a guy I knew had a stroker AMF Harley and it went like hell, he said it actually became more reliable but I assumed that was the result of all the other changes he also made being an aircraft mechanic.
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Post by mykul on Oct 19, 2011 10:05:36 GMT -5
You can surely obtain a longer chain? Failing that you can add a link or two yourself but DO NOT use a spring link to join it, you have to peen over the roller ends onto the side plates like the manufactured versions do. A lot of high power bikes use 'endless' drive chains now so the stuff to do it is out there.
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Post by mykul on Oct 19, 2011 10:08:40 GMT -5
I too have a hard commute and with larry's experience here I don't believe BBK's are entirely without consequence. Mine only lasted about 10,000 miles before I had the same problem, connecting rod knocking on the crankshaft. I previously thought it was the crank bearings but after ripping the engine apart last month it was connecting rod bearing. I think 10k miles on a pumped up small motor isn't all that unreasonable. What is the big end bearing? White metal shells or rollers? |
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Post by larry001964 on Oct 19, 2011 10:12:47 GMT -5
Larry, Sounds like you got it all figured out. I'm glad to hear it's all going together OK for you. I hope you can soon be riding again. I can't wait to hear your engine roar. Good Luck & keep us posted. We all know a 150cc would be cheaper but you wouldn't have half the fun! John Ohh ill figure it out, will just take time. |
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Post by larry001964 on Oct 19, 2011 10:17:12 GMT -5
You can surely obtain a longer chain? Failing that you can add a link or two yourself but DO NOT use a spring link to join it, you have to peen over the roller ends onto the side plates like the manufactured versions do. A lot of high power bikes use 'endless' drive chains now so the stuff to do it is out there. Yea that was my thought too, Ill call Enviormoto and see if he has any thoughts on a longer chain.. He's really been a big help on this... I dont often give kutos to some one, but honestly he's earned it.. |
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Post by organdoughnut on Oct 19, 2011 16:06:06 GMT -5
looking forward to the results if you get your own Internet can you take a video of it running and accelerating please would love to see it , good job  |
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Post by larry001964 on Oct 22, 2011 9:51:03 GMT -5
October 22,
Took a break from buying parts, bought instead a cheap laptop and having my internet installed.. Soon Ill be able to show pictures and video of this rebuild.. You know its almost impossiable to do anything now days without internet and a computer of some kind..
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Post by organdoughnut on Oct 22, 2011 14:03:49 GMT -5
Yeah thats the problem its just so usefull, and wehre all looking forward to seeing it run  |
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Post by larry001964 on Nov 5, 2011 10:29:26 GMT -5
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Post by larry001964 on Nov 5, 2011 10:43:22 GMT -5
October 30,
The Hoca stroker crankshaft conclusion:
orginal crankshaft rod length.. 106.65 mm
Hoca crankshaft rod length .....105.85 mm
difference of................... 0.50 mm
Variance in measurements can be as much as 0.02 mm,( gasket measurements are the inconsistency some are as much as 0.52 mm ) I don't expect this to effect my compression ratio much. If I can place that piston within 0.02 mm of where it's designed to operate by NCY ( plus or minus ), I think all will be fine.
What Hoca did was to move the rod out 1.30 mm for a total distance of 2.60 mm However they compensated by shorting the rod. So my conclusion is that even thought it is a stroker crank they stayed within the confines of the standard gy6 engine's engineering.. Meaning only 1 extra base gasket of 0.50 mm is needed using NCY parts and 50 mm head ( a must have ). I did have my old oil pump gear pressed on it, but other than that no extras are needed.
Since the piston rod is shortened the piston only travels an extra 0.50 mm up and 0.50 mm down the cylinder. Little additional cc's will be gained with the stroker crankshaft.. However it's main advantage is the additional torque that is gained from the 1.30 mm offset of the crankshaft rod, and in my case the NCY Performance cam ( suppose to provide more low and mid range torque ) larger head, and better flow of engine gasses fuel/air and exhaust. This is my conclusion. Since I used the NCY exclusively my findings are for the NCY, any other kits may have different findings..
I have decided to continue using my original carb for now, The 50 cc bb head can accommodate a bigger carb. but I believe my original will be fine, I will merely up jet it, I think both idle and main jet this time. I don't think as a 83 I would have to do this, but as a 93 cc I believe I will need more. I'm well beyond even a normal BBK kit here.. Again Ill have to have some work done. I want to replace the rubber diaphragm, and I have a stuck bolt that needs to be drilled out and re tapped.. Best to do it now and get it done..
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Post by Enviromoto on Nov 5, 2011 18:30:56 GMT -5
Interesting.
Keep up the good work.
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Post by skuttadawg on Nov 5, 2011 21:59:00 GMT -5
Bummer you had some gremlins on rebuild . Thanks for sharing your info on the stroker . I would like to hear what you think after its up and running . I read with stroker you need extra base gasket and or a shim . With the shim or gasket would the piston be at the same TDC in the combustion chamber . If its not as close you might have less compression . Does the crank use ball beraring or roller bearings ? Do you know the max RPM it will support ?
I see you have NYC parts but I think its NCY is what you meant to say .
Could you tell a dif with cam upgrade ?
Since you ride long distances ever thought about installing an oil cooler ?
Sounds like you will have a fun toy with premium parts to enjoy .
Did you upgrade the suspension or tires ?
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Post by larry001964 on Nov 6, 2011 12:24:06 GMT -5
Bummer you had some gremlins on rebuild . Thanks for sharing your info on the stroker . I would like to hear what you think after its up and running . I read with stroker you need extra base gasket and or a shim . With the shim or gasket would the piston be at the same TDC in the combustion chamber . If its not as close you might have less compression . Does the crank use ball bearing or roller bearings ? Do you know the max RPM it will support ? I see you have NYC parts but I think its NCY is what you meant to say . Could you tell a dif with cam upgrade ? Since you ride long distances ever thought about installing an oil cooler ? Sounds like you will have a fun toy with premium parts to enjoy . Did you upgrade the suspension or tires ? Thanks for the NCY correction skuttadawg I fixed it. I did take some Micrometer reading of the HP cam, they were interesting actually the cams lobs were exactly the same measurement as the orginial. The difference is in the position of the lobs and duration of lift.. I too can't wait to see how it performs. Actually yes I em considering building a liquid cooling system on the engine. this system would drive a pump on the stator side of the engine, along with a mechanical fuel pump for fuel injection.. I'm still in the design phase on this so I em not sure yet if i will even build it. The Hoca Stroker crankshaft was pretty much identical to the original the bearing were exactly the same type.. I have upgraded the suspension system a little, as I bought new motor mounts made of a better rubber. Tires I'm planning on buying Pirelli tires, and having them balanced. Most of the vibrations at higher speeds are caused by unbalanced tires, With 50 cc scooters there's really no need for balanced tires when your top speed is 25 to 35 mph.. So very very few manufactures ever bother with this. I'm actually planning to move very soon to Delphi Indiana as that's where my job is.. It will be a much shorter drive every day on the scooter. in winter weather that's a plus. But there will be many occasions still where I will be driving it over 60 miles a day so this upgrade is not a wasted one.. From what I can tell about the stroker crankshaft, It's identical to the stock in most respects, better metal and hardeners ( as advertized ) so I'm guessing it will probably have the same rpm limitations as the original, Nothing over 8 grand. I did goof in my last parts order, as I wanted 7 gram sliders and bought 5 gram by mistake, to late to change it as the parts have already been shipped.. So at some point Ill probably have to reorder 7 gram sliders... Ohhh well that's life.. Since Ladybug effectively died that Saturday taking me to work, I have decided to rename my Scooter.. I have decided on the name Fawkes the name of the Phoenix in Harry Potter.. Rip Ladybug you served me well, welcome Fawkes. Now for the bad news... How much did this all cost me ? LOL 434.39 Enviormoto gave me 10 % scootdawg member discount 43.59 so the total for Enviormoto is 390.80 390.80 214.98 Parts For Scooters ( free shipping) 319.50 Scrappy 20.00 NAPA 5.00 Engine De greaser and car wash. 879.28 Total... So Far Not done yet |
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Post by skuttadawg on Nov 8, 2011 0:21:11 GMT -5
Wow so we can get a discount by being a member here  ?? Cool . I have seen a GY6 BBK that also converted to water cooling www.mbe-motorsports.com/catalog/index.php/cPath/19_106_104?osCsid=mrdg4avagrlnvn45ietov2omi7 but no kit for 50cc to convert to LC . EFI you will need eletric fuel pump . My Echarm has EFI with Ducatti ECU . I turn the key and hear the pump pressure up and the I hit the starter button . EFI is great , more efficient , no bogging or carb issues like clogged jets . If you wanna go or seem to go fast ride with a buddy who has a stock 50 lol . I loved outrunning stock 50s with my BBK . |
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Post by larry001964 on Nov 8, 2011 12:44:11 GMT -5
Wow so we can get a discount by being a member here ?? Cool . I have seen a GY6 BBK that also converted to water cooling www.mbe-motorsports.com/catalog/index.php/cPath/19_106_104?osCsid=mrdg4avagrlnvn45ietov2omi7 but no kit for 50cc to convert to LC . EFI you will need electric fuel pump . My Echarm has EFI with Ducatti ECU . I turn the key and hear the pump pressure up and the I hit the starter button . EFI is great , more efficient , no bogging or carb issues like clogged jets . If you wanna go or seem to go fast ride with a buddy who has a stock 50 lol . I loved outrunning stock 50s with my BBK . Well some suppliers here give discounts, Not all, best to let them know when you place your order that you are a scootdawg member and give them your userid... I deal almost exclusively with suppliers here on scootdawg, they are very reputable and I have a means of voicing any misgivings if needed.. So far that hasn't been the case.. The EFI Idea im working on does not use an electric fuel pump, it uses a mechanical, with a bladder system, not unlike the water system in a country house with a well for water.. It's benefits are that its a lot easier on the electrical system, and will start the scooter even when the battery is dead. as the ECU has it's own battery and only uses the scooters power to keep it charged. It's still in the works as i said i may never build it.. But that's the concept.. Got the most of the engine back together today, Top half is done, crank is done, just a few more checks and ill start torque down the bolts... We are getting very very close.. I'm so excited !!! |
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Post by Enviromoto on Nov 10, 2011 18:58:57 GMT -5
Hows it going?
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?? Cool .