Gear up kit for Buddy 50 Confirmed!! 70mph Runner

[babblefish]

Forgot to mention, find out how the Zuma crank gets it's rod bearing lubricated. It may not be compatible with the Buddy lubrication system. If totally different, it could cause oil starvation not only to the rod bearing, but also to the main bearings. The reason I mention this is because some 2T engines inject their oil directly into the rod bearing through the main bearing. Not sure if the Buddy system does this.

[jickel]

Your ignition timing sensor looks pretty beat up. Might want to check and make sure it's still good. Also, there's a good chance that your crank failed the way it did due to the high RPMs causing a harmonic vibration to occur with the stator flywheel which over time caused the crank to break due to metal fatique. Whatever you do in the future to repair the engine, it would be wise to have the flywheel balanced, dynamically if possible. That's a lot of weight hanging off the end of the crank so any imbalance will be greatly magnified at higher RPMs. For sustained high RPM use though, balancing the flywheel with the crank would be best, but I don't know of any shop who can do this for small engines. Automotive engines, yes.

Yeah the stator housing took the magnetic pickup out so that's why the lights went out and I coasted to a sad stop when this happened. I'll replace all of that when I swap in the new crank.

I just got the measurements for the Zuma crank. The variator side is 1mm smaller than our PGO cranks, so a Zuma aftermarket variator will be needed, which will eliminate the electric start. I may just take the easy way out and go with the Motoforce crank and set the scoot not exceed 15k rpms.


Stock Zuma Crank Specs:

[Ohh buddy]

Your ignition timing sensor looks pretty beat up. Might want to check and make sure it's still good. Also, there's a good chance that your crank failed the way it did due to the high RPMs causing a harmonic vibration to occur with the stator flywheel which over time caused the crank to break due to metal fatique. Whatever you do in the future to repair the engine, it would be wise to have the flywheel balanced, dynamically if possible. That's a lot of weight hanging off the end of the crank so any imbalance will be greatly magnified at higher RPMs. For sustained high RPM use though, balancing the flywheel with the crank would be best, but I don't know of any shop who can do this for small engines. Automotive engines, yes.

Yeah the stator housing took the magnetic pickup out so that's why the lights went out and I coasted to a sad stop when this happened. I'll replace all of that when I swap in the new crank.

I just got the measurements for the Zuma crank. The variator side is 1mm smaller than our PGO cranks, so a Zuma aftermarket variator will be needed, which will eliminate the electric start. I may just take the easy way out and go with the Motoforce crank and set the scoot not exceed 15k rpms.


Stock Zuma Crank Specs:

Those specs of the Zuma crank maybe a bit helpful for me.. I would have to measure the Buddy crank and see what would work and would not. If it at least installs inside the PGO crankcase and rotate freely without any clearance issues this could be a good start of upgraded cranks on the market

[Ohh buddy]

I wonder if the crank kits used on Yamaha Zumas will work for us? This would eliminate the oil pump, but we could just premix the old fashioned way anyway.

I'm going to measure my crank, and luckily my friend has a stock Zuma crank laying around that he'll measure and compare.

https://www.scooter-attack.com/shop/en/ ... 6-HPC.html

He's running this crank now in his Zuma, so if the only thing we lose is the oil pump then I'll order this setup. It's possible we may have to switch to a different variator and bearing setup, but I'm thinking/hoping the shafts are the same length and diameter.

Dunno, the Buddy and Zuma cranks sure look different, though the bore and stroke are the same:

they do look different but not by much IMO. if I had a zuma crank laying around I wouldn't be wasting any time installing it to see if it has any clearance issues inside the casing😊

[Meis]

Thread resurrection!

This is a great thread full of super useful info. What is the brand of that digital tachometer?

[sc00ter]

Looks like a CenTec from Harbor Freight.

[Ohh buddy]

I believe you are correct I recently just bought one from Harbor Freight.. this micrometers seems pretty precise

[jickel]

Thread resurrection!

This is a great thread full of super useful info. What is the brand of that digital tachometer?

That's a Stage 6 tach. I have the same one on my buddy. Easy to install and works great:

http://www.scooter-attack.com/rev-count ... 30-39.html

Follow up on the crank:

I ended up going with an Athena 10mm replacement crank since I'm not planning on spinning to 16k rpms. Was working great until I burned up my Stage 6 MK2 head earlier this summer (probably shouldn't have been winding it out in 100 degree temps). I heard a rumor that Stage 6 got bought out, and finding another MK2 sport pro head is hard to find.

Any update with OP's scoot?

[Ohh buddy]

Nahhh it's been parked for about a few months now waiting for the weather to cool off again so I can dig back in again.. not sure what crank I'm going to go with yet. I miss riding it thoo

[jickel]

I hear ya. I melted my S6 MK2 head in the middle of summer because I refused to give the scoot a break on some long pulls. The temps are brutal on these high rpm air cooled heads. I'm trying an Athena Evolution head this week (and a larger main jet too lol). Hope to be hitting 70 mph again soon!


Honestly if I were to do the crank all over again, I'd just go big with a 94 cc kit (or at least an 80cc kit if you want to keep it air cooled)

[Ohh buddy]

I hear ya. I melted my S6 MK2 head in the middle of summer because I refused to give the scoot a break on some long pulls. The temps are brutal on these high rpm air cooled heads. I'm trying an Athena Evolution head this week (and a larger main jet too lol). Hope to be hitting 70 mph again soon!


Honestly if I were to do the crank all over again, I'd just go big with a 94 cc kit (or at least an 80cc kit if you want to keep it air cooled)

any updates on your project? I decided to pull the trigger and buy the bgm full circle crankshaft.. I was able to free up some dough so it was my moment to buy it.. and I'm quite pleased with it

[Ohh buddy]

Here are some pics of that crankshaft ive purchased it's a nice piece a good upgrade if you're running a mid-race 70cc setup.. this was listed for fitment for a PGO Big Max 50, Pmx 50, T-Rex 50 and other Pgo 50cc 2t scoots.. I also will be installing crank today hopefully everything goes smoothly

[babblefish]

Very nice looking crank. Please do let us know how things turn out.

[jickel]

I hear ya. I melted my S6 MK2 head in the middle of summer because I refused to give the scoot a break on some long pulls. The temps are brutal on these high rpm air cooled heads. I'm trying an Athena Evolution head this week (and a larger main jet too lol). Hope to be hitting 70 mph again soon!


Honestly if I were to do the crank all over again, I'd just go big with a 94 cc kit (or at least an 80cc kit if you want to keep it air cooled)

any updates on your project? I decided to pull the trigger and buy the bgm full circle crankshaft.. I was able to free up some dough so it was my moment to buy it.. and I'm quite pleased with it

Nice crank! Did you get it installed yet? Is it a 10mm? Seems like we don't get any 12mm love for the PGOs. One thing to note is that I ended up breaking the Athena crank believe it or not at the exact same spot my OEM crank broke (at the stator), so I ditched that motor and swapped in a low mile OEM long block. The crank broke under light load, so I'm wondering if these OEM ignition bell housings aren't well balanced from the factory. Probably a good idea to switch to a lighter inner rotor ignition setup if you plan on spinning this thing pretty high in RPMs.

I figure if I'm going to do the crank again, it's time to go 94cc and a watercooled setup. So far the stock crank is holding up fine (not revving past 11k with my setup).

[Ohh buddy]

Geezz it's been that long since I last posted about the bgm full circle crank? . but anyway to make things simple and short, The fitment of the crank was simple even the stock OEM main bearings from the original crank fit easily. I'm even using the stock oil pump with the Bgm crank!! The flywheel and the stock variator parts fit with no issues. I've put about 100 miles on the crank and it's been working flawlessly. Shoot it even seems like it's a little more peppier than the stock crank being that a full circle crank is able to increase the primarily crankcase pressure. But I am not done with this baby yet..

[Ohh buddy]

I hear ya. I melted my S6 MK2 head in the middle of summer because I refused to give the scoot a break on some long pulls. The temps are brutal on these high rpm air cooled heads. I'm trying an Athena Evolution head this week (and a larger main jet too lol). Hope to be hitting 70 mph again soon!


Honestly if I were to do the crank all over again, I'd just go big with a 94 cc kit (or at least an 80cc kit if you want to keep it air cooled)

any updates on your project? I decided to pull the trigger and buy the bgm full circle crankshaft.. I was able to free up some dough so it was my moment to buy it.. and I'm quite pleased with it

Nice crank! Did you get it installed yet? Is it a 10mm? Seems like we don't get any 12mm love for the PGOs. One thing to note is that I ended up breaking the Athena crank believe it or not at the exact same spot my OEM crank broke (at the stator), so I ditched that motor and swapped in a low mile OEM long block. The crank broke under light load, so I'm wondering if these OEM ignition bell housings aren't well balanced from the factory. Probably a good idea to switch to a lighter inner rotor ignition setup if you plan on spinning this thing pretty high in RPMs.

I figure if I'm going to do the crank again, it's time to go 94cc and a watercooled setup. So far the stock crank is holding up fine (not revving past 11k with my setup).

I installed the crank a couple of months back. I'm quite pleased with it should be stronger than stock the crank supposably can handle high RPM if I remember correctly. But that flywheel for the stator is probably not good for high RPM it's probably not balanced very well or just too much weight spending at the end of the crank causing fatigue and then failure. I've been searching around for a performance or smaller alternator flywheel, and come to my findings Stylepro has come out with a racing alternator for pgo 50cc scoots, what it looks like a copy of the ncy version for minarellis.

[scottwinatl]

Hey All, new here and new to scootering....not technical at all. Use my scooter as a daily commuter here in Atlanta. Can cruise on the flat most of the time about 42 if the speedometer is correct. Have trouble on some hills, some I stay at 30-35 others bog me down to 20-25 have read about the 70CC kits and am interested in having it installed on mine. Do they work, will I get more power up the hills, and a little faster on the flat, and is there anyone in Atlanta that I can go to, to install it?

BTW, bought the 2009 a few months ago, it only had 1600 miles on it, almost like new. Loving it!

Thanks!

[cummingsjc]

Yes, the 70cc kits will give you more low end power and top end speed. They generally involve a complete re-tuning of the engine exhaust, air flow, and transmission systems as a result of the increased displacement. Many folks on here like them a lot but most will admit that adding 70cc kits will generally require regular tweaking to run in peak performance and will not be as durable as the stock parts. You will probably lose some degree of reliability from your Buddy with some folks saying you will only get 2-3 years of use before it needs to be replaced (obviously, your mileage will vary based on your riding style, size, roads, etc). The other discussion that will come up will be that if you needed more speed you should upgrade to a bigger displacement scooter, such as a Buddy 125, that will be much more reliable, faster, fuel efficient cheaper than upgrading a Buddy 50. Any reputable scooter dealer should be able to install a BBK for you.

As a curiosity, are you running the Buddy 50 in order to avoid getting a motorcycle license? That is a major reason we see on the forums for folks buying 50's then realizing they don't have enough power. If that is the case, do yourself a favor and upgrade your license and get a bigger scoot.

[Ohh buddy]

Well since Photobucket is now asking users to pay for services to post your images up for third-party use($400 a year!) I will be removing all photos and taking them elsewhere but I will repost on here all the replacement images that have been blocked by Photobucket..It may take some time unfortunately.

[babblefish]

Well since Photobucket is now asking users to pay for services to post your images up for third-party use($400 a year!) I will be removing all photos and taking them elsewhere but I will repost on here all the replacement images that have been blocked by Photobucket..It may take some time unfortunately.

I always upload pictures directly from my computer to MB...

[jickel]

any updates on your project? I decided to pull the trigger and buy the bgm full circle crankshaft.. I was able to free up some dough so it was my moment to buy it.. and I'm quite pleased with it

Nice crank! Did you get it installed yet? Is it a 10mm? Seems like we don't get any 12mm love for the PGOs. One thing to note is that I ended up breaking the Athena crank believe it or not at the exact same spot my OEM crank broke (at the stator), so I ditched that motor and swapped in a low mile OEM long block. The crank broke under light load, so I'm wondering if these OEM ignition bell housings aren't well balanced from the factory. Probably a good idea to switch to a lighter inner rotor ignition setup if you plan on spinning this thing pretty high in RPMs.

I figure if I'm going to do the crank again, it's time to go 94cc and a watercooled setup. So far the stock crank is holding up fine (not revving past 11k with my setup).

I installed the crank a couple of months back. I'm quite pleased with it should be stronger than stock the crank supposably can handle high RPM if I remember correctly. But that flywheel for the stator is probably not good for high RPM it's probably not balanced very well or just too much weight spending at the end of the crank causing fatigue and then failure. I've been searching around for a performance or smaller alternator flywheel, and come to my findings Stylepro has come out with a racing alternator for pgo 50cc scoots, what it looks like a copy of the ncy version for minarellis.

Just checking in again. How's that crank holding up for you? I broke my 2nd Athena crank at the alternator again, so I'm going to either look for this Stylepro ignition or buy a friend's 80 mph LC Zuma and call it a day.

Is this the ignition you're talking about? http://scootertuning.ca/en/ignition/700 ... acing.html

[Ohh buddy]

Nice crank! Did you get it installed yet? Is it a 10mm? Seems like we don't get any 12mm love for the PGOs. One thing to note is that I ended up breaking the Athena crank believe it or not at the exact same spot my OEM crank broke (at the stator), so I ditched that motor and swapped in a low mile OEM long block. The crank broke under light load, so I'm wondering if these OEM ignition bell housings aren't well balanced from the factory. Probably a good idea to switch to a lighter inner rotor ignition setup if you plan on spinning this thing pretty high in RPMs.

I figure if I'm going to do the crank again, it's time to go 94cc and a watercooled setup. So far the stock crank is holding up fine (not revving past 11k with my setup).

I installed the crank a couple of months back. I'm quite pleased with it should be stronger than stock the crank supposably can handle high RPM if I remember correctly. But that flywheel for the stator is probably not good for high RPM it's probably not balanced very well or just too much weight spending at the end of the crank causing fatigue and then failure. I've been searching around for a performance or smaller alternator flywheel, and come to my findings Stylepro has come out with a racing alternator for pgo 50cc scoots, what it looks like a copy of the ncy version for minarellis.

Just checking in again. How's that crank holding up for you? I broke my 2nd Athena crank at the alternator again, so I'm going to either look for this Stylepro ignition or buy a friend's 80 mph LC Zuma and call it a day.

Is this the ignition you're talking about? http://scootertuning.ca/en/ignition/700 ... acing.html

Yes that's the ignition rotor kit I plan on getting soon but as far as the bgm crank it's holding up real good !!!

[jickel]

I installed the crank a couple of months back. I'm quite pleased with it should be stronger than stock the crank supposably can handle high RPM if I remember correctly. But that flywheel for the stator is probably not good for high RPM it's probably not balanced very well or just too much weight spending at the end of the crank causing fatigue and then failure. I've been searching around for a performance or smaller alternator flywheel, and come to my findings Stylepro has come out with a racing alternator for pgo 50cc scoots, what it looks like a copy of the ncy version for minarellis.

Just checking in again. How's that crank holding up for you? I broke my 2nd Athena crank at the alternator again, so I'm going to either look for this Stylepro ignition or buy a friend's 80 mph LC Zuma and call it a day.

Is this the ignition you're talking about? http://scootertuning.ca/en/ignition/700 ... acing.html

Yes that's the ignition rotor kit I plan on getting soon but as far as the bgm crank it's holding up real good !!!

Great to hear! Hope it's the last crank you'll ever need for your scoot. I've got the ignition system on my scoot now. Word of caution: Make sure you order a 3 bolt pattern fan for it. Luckily my local scoot shop had an NCY ignition that provided a 3 bolt fan I could use.