Modern Buddy

Posted: **Thu Aug 30, 2012 9:45 pm**

Hello:

Anyone did a Buddy 125cc upgrade with a Prima 161cc Big Bore Kit?
My indicated spedometer speed before upgrade sometimes went over 60MPH. After Big Bore kis installation, now max speed is only 42MPH indicated speed.

I already upjetted from orignina 92 to 102. Suppose to go faster, not slower. Anyone got any ideas on what the problem is?

Thanks

Posted: **Fri Aug 31, 2012 1:28 am**

Who installed the kit? I very nearly set my cam timing to the wrong mark.

Posted: **Fri Aug 31, 2012 3:11 am**

I did the 161 kit with a Prima pipe and NCY big valve head. The scooter runs great. Lots more power and top end speed. I am reaching 75mph indicated on my speedometer.

I am looking to upgrade to a 26mm carb and upgrade the transmission now! I am afraid I am hooked...

Posted: **Fri Aug 31, 2012 3:39 am**

rick71454 wrote:Hello:

Anyone did a Buddy 125cc upgrade with a Prima 161cc Big Bore Kit?
My indicated spedometer speed before upgrade sometimes went over 60MPH. After Big Bore kis installation, now max speed is only 42MPH indicated speed.

I already upjetted from orignina 92 to 102. Suppose to go faster, not slower. Anyone got any ideas on what the problem is?

Thanks

I'm with lovemysan on this one......sounds like the cam is one or two teeth off.

Rob

Posted: **Fri Aug 31, 2012 3:55 am**

jaswol wrote:I did the 161 kit with a Prima pipe and NCY big valve head. The scooter runs great. Lots more power and top end speed. I am reaching 75mph indicated on my speedometer.

I am looking to upgrade to a 26mm carb and upgrade the transmission now! I am afraid I am hooked...

I went transmission first, then up jetted.
New Carb came in and was the wrong throttle assembly. ...I got it working, but achieved the same result with the other jet on the stock exhaust.
I never did repurchase the 26mm.
Did you remove the air box?

Posted: **Fri Aug 31, 2012 8:26 pm**

Hello Jaswol:

Thanks for your response. YOu mean Prima exhaust pipe? Would you have gotten nearly the same performance withoug this pipe.

Rick71454

Posted: **Fri Aug 31, 2012 8:31 pm**

Hello Monamibuddy:

Thanks for your response. No I did not remove the air box, but I know about air flow characteristics. The scooter should not run 2/3 of original speed with a 161cc Big Bore Kit installed even if that is the only upgrade done.

Rick71454

Posted: **Fri Aug 31, 2012 8:40 pm**

Hello Lovemysan;Robbie:

Thanks for your response........
A mechanic at a Genuine dealership here in Oregon suggested to me that the problem could be in the cam or timing as you mentioned. They said if off by even one tooth, it would cause the scooter to run slower. The shop that did the actual work, did say they worked with the timing chain while servicing my scooter. A local scooter shop did the work.

Rick71454

Posted: **Sat Sep 01, 2012 12:54 am**

rick71454 wrote:Hello Monamibuddy:

Thanks for your response. No I did not remove the air box, but I know about air flow characteristics. The scooter should not run 2/3 of original speed with a 161cc Big Bore Kit installed even if that is the only upgrade done.

Rick71454

Rick, Didn't mean to HiJack your thread. My response was directed @jaswol, and his comment about the carb. Sorry bud. -Mike

Posted: **Sat Sep 01, 2012 1:47 am**

rick71454 wrote:Hello Lovemysan;Robbie:

Thanks for your response........
A mechanic at a Genuine dealership here in Oregon suggested to me that the problem could be in the cam or timing as you mentioned. They said if off by even one tooth, it would cause the scooter to run slower. The shop that did the actual work, did say they worked with the timing chain while servicing my scooter. A local scooter shop did the work.

Rick71454

So if a local shop did the work, it seems like you should take it back to them and have them adjust it correctly. I would think that the the adjustments should be done free of charge, since they apparently didn't do the work correctly in the first place.

Posted: **Sat Sep 01, 2012 3:46 am**

Monamibuddy: No, I did not remove the air box. I had the work done at my local shop. I had a ring problem and needed to replace the cylinder head anyway, so I upgraded with the stage 2 kit. The shop did have to modify the box in one place due to the cylinder head. I have thought about removing it, but needed to do more research. Do you have a recommendation? So, transmission should be my next upgrade...?

Posted: **Sat Sep 01, 2012 3:55 am**

Rick71454: I purchased the 161 cylinder and pipe as part of the stage 2 kit + big valve kit. I feel like the exhaust pipe and big valve kit were important, but I am not sure how much more performance I am getting over not installing those items because I did everything at once. Scooterworks claims that the cylinder kit is a 36% increase over stock by itself, and a 45% increase with the valve kit. No mention of the exhaust, although I highly recommend it just based on how my buddy sounds now!

Posted: **Sat Sep 01, 2012 5:22 am**

Hello..........

To those who mention about the cam might be off. I learned there is a device on the cycliner head called a CCT Cam Chain Tensioner.
It has an adjustable bolt. Do you know if adjusting this bolt would lead to a faster scooter? I noticed my engine might be at high RPMs, but goes so slow in caparison.

Rick71454

Posted: **Sat Sep 01, 2012 5:26 am**

Hello Pdxrita:

Your suggestion to take my Buddy back to the shop is one I will take. Wise thanks..Others say the same. I noticed you are from Portland Oregon too.

Rick71454

Posted: **Sat Sep 01, 2012 12:12 pm**

rick, I had to retune my trans after installing the 161 kit. I had I think 11 gram sliders and yellow NCY torque spring. The engine made more torque throughout the rev range and increased rpms everywhere. I put the stock spring in it. I didn't check top speed at the time because I was breaking it in. The prima pipe will won't make a huge difference in fact no discernible difference on a stock bike. Not sure how much top end you'll pick up because the cylinder head is the limiting factor on the top end. The small intake and exhaust ports combined with the long stroke crank are what makes a buddy such fun around town giving it lots of low-midrange torque. Acceleration will be stronger everywhere in the rev range and it will be hard to tell the difference after a few rides. My buddy with a 161 kit and pipe has no trouble pulling the front tire off the ground and would easily wheelie if I had any since of balance. I can get to 62mph indicated, which is about 51-52mph. Might be a little faster since I recently down jetted to a 100 main.

Posted: **Sat Sep 01, 2012 1:47 pm**

rick71454 wrote:Hello..........

To those who mention about the cam might be off. I learned there is a device on the cycliner head called a CCT Cam Chain Tensioner.
It has an adjustable bolt. Do you know if adjusting this bolt would lead to a faster scooter? I noticed my engine might be at high RPMs, but goes so slow in caparison.

Rick71454

I wouldn't think so. The tensioner is to take slack out after the chain after installing a different cam or after the chain stretches. A Buddy 125 has static timing and tightening the chain isn't going to change that.

Posted: **Sat Sep 01, 2012 1:48 pm**

Robbie wrote:
rick71454 wrote:Hello:

Anyone did a Buddy 125cc upgrade with a Prima 161cc Big Bore Kit?
My indicated spedometer speed before upgrade sometimes went over 60MPH. After Big Bore kis installation, now max speed is only 42MPH indicated speed.

I already upjetted from orignina 92 to 102. Suppose to go faster, not slower. Anyone got any ideas on what the problem is?

Thanks
I'm with lovemysan on this one......sounds like the cam is one or two teeth off.

Rob

Agree...this is the first thing I would check. If the proper spacers weren't used during the install it will be impossible to get the timing right.

Posted: **Sat Sep 01, 2012 3:33 pm**

Hello BuddRaton:

Thanks.........
I will approach the shop with mention of your thoughts about the spacers and timing not being right, such that full potential speed cannot be acheived if done less than correctly.

Rick71454

Posted: **Sat Sep 01, 2012 6:17 pm**

rick71454 wrote:Hello:

Anyone did a Buddy 125cc upgrade with a Prima 161cc Big Bore Kit?
My indicated spedometer speed before upgrade sometimes went over 60MPH. After Big Bore kis installation, now max speed is only 42MPH indicated speed.

I already upjetted from orignina 92 to 102. Suppose to go faster, not slower. Anyone got any ideas on what the problem is?

Thanks

Wow. Do you do a lot of hills? I regularly have an indicated speed of 65 - 70....today it got up to 75 (GPS said that was 65), though I confess that was slightly downhill. On the level I was getting 62-63 per GPS. Going up a bit of an incline it dropped to GPS of 57.

This is a stock 125, and I weigh (

) 165.

Posted: **Sat Sep 01, 2012 9:20 pm**

Hello michelle_7728;

Thanks for responding.............
You got a stock 2009 Buddy 125, you weigh 165, and you get over 60 MPH GPS? You got one of the better ones and your blessed with it. My stock 2009 Buddy 125 rarely got over 50MPH GPS. I weigh 170. If had yours, I would have never though about trying to make it go faster with upgrades.

Rick71454

Posted: **Sun Sep 02, 2012 7:26 am**

Actually, both of my Buddy 125s perform the same. I'm convinced my windshields help....do you have one?

Posted: **Sun Sep 02, 2012 11:05 pm**

Hello michelle_7728;

Yes, I do have a windshield, but I have not yet installed it. I will do it before winter arrives. I agree it might help increase speed, since it is likely smaller than the surface space of most riders. As such, it minimizes wind resistance deflecting it before wind hits the rider. It also keeps that cold cold oh so cold winter wind off our upper body.

Rick71454

Posted: **Mon Sep 03, 2012 2:26 am**

Rick, definitely get that bike back to the shop. Do so without giving them attitude or telling them how to do their job and it should go well.

My 150 has been getting to about 70 mph indicated (and could do better if I had a long enough stretch of road without State Patrol

). I don't have a GPS but that's gotta be around 60 real mph. I haven't increased the bore or changed the head; just done some stuff to the transmission.

I realize a new cylinder and piston is like a new motor and won't be broken-in yet, but you shouldn't see such a loss with those upgrades.

Posted: **Mon Sep 03, 2012 8:01 am**

Hello Buddy Pals:

I took my Buddy 125 back to the shop that did the Big Bore 161cc upgrade. The owner of the shop went into the mechanics area. The mechanic who actual work on my scooter came out oblivious that I wanted him to check out his own work. Instead he went on a spiel about how my Scooter could not have incresed speed as a stand alone Big Bore upgrade. He showed off his own 70cc converted to go very fast and when on to tell me I need to do this and do that to get any extras speed. I felt like it was a shine off, get rid of the former customer conduct by the shop.
They were not going to cooperate short of my going to the state on this.

I already did some of their suggestions such as adjsuting the air fuel mixture, screw, up jetted carburetor from stock 92 to 102, and I tried riding it with less air intake restriction. None of it improved speed. I think the CCT Cam Chain Tensioner needs adjustment or someing inside the cyclinder needs adjustment.

I
So I am taking it elsewhere to fix it. I am about to prove if the first shop messed up. I will let you know.

Thanks
Rick71454

Posted: **Mon Sep 03, 2012 12:38 pm**

The cam chain adjuster only removes the free play from the cam drive chain.
The cam is up in the cylinder head and this assembly had to be removed to exchange the cylinder and piston.

I maintain that the cam chain was inadvertently reinstalled onto the cam gear at least one tooth off, causing the cam to operate several degrees advanced or retarded relative to the crankshaft.

The modification should have provided a increase in the machines ability to achieve a given speed compared to stock.
The top speed acieveable would be the same or higher.....it would just reach that point quicker.

If the cam chain adjustment (free play) was incorrect your complaint would be noise related, not power related.

Rob

Posted: **Mon Sep 03, 2012 1:06 pm**

OK lets go over it again.

First there is no way you should have such a drastic reduction in power.

Second we have established that the tensioner is not the problem.

Third The cam timing may be off by a tooth, but it is more likely that an "experienced" mechanic used the wrong thickness spacer at the bottom of the jug causing the cam to be off by a few degrees. There are different sized spacers depending on what head is used. Missing a tooth would put your timing off by many degrees, the wrong sized spacer would put if off by a few degrees...enough to make it run like crap.

I haven't done a tooth count (anybody know what it is?) but its a small cam so lets say that it has 36 teeth. If you are one tooth off your timing will be off by 10 degrees. I don't see it even starting being off that much.

Posted: **Tue Sep 04, 2012 12:03 am**

Hello BuddyRaton:

Thanks for your further clarification........
Might you be a scooter mechanic? Even if not, you know alot so thanks.
I will address this spacer thing you mention with the next person working on my scooter. It idles excellent and does run between 0-42 MPH actual on level ground. Sould run at least 60MPH actual.

I will keep everyone tuned in.

Rick71454

Posted: **Tue Sep 04, 2012 1:56 am**

I'm just a tinkerer!

I have a shop set up but I don't work on anybody's bike for money. People come over and I help them with their projects or they help me with my projects. That way it stays fun, the way I like it... and I'm not responsible for what happens to someone's scooter.

Posted: **Tue Sep 04, 2012 11:38 am**

BuddyRaton wrote:OK lets go over it again.

First there is no way you should have such a drastic reduction in power.

Second we have established that the tensioner is not the problem.

Third The cam timing may be off by a tooth, but it is more likely that an "experienced" mechanic used the wrong thickness spacer at the bottom of the jug causing the cam to be off by a few degrees. There are different sized spacers depending on what head is used. Missing a tooth would put your timing off by many degrees, the wrong sized spacer would put if off by a few degrees...enough to make it run like crap.

I haven't done a tooth count (anybody know what it is?) but its a small cam so lets say that it has 36 teeth. If you are one tooth off your timing will be off by 10 degrees. I don't see it even starting being off that much.

Uh,

One tooth of a 36 tooth cam sprocket is five degrees since two turns of crank for one turn of cam.....and, they will run very well if retarded.....and they run out of power as RPM gets higher.

It doesn't really matter.....the cam tooth count is always double the crank tooth count.

Rob

Posted: **Tue Sep 04, 2012 12:08 pm**

Robbie wrote:
BuddyRaton wrote:OK lets go over it again.

First there is no way you should have such a drastic reduction in power.

Second we have established that the tensioner is not the problem.

Third The cam timing may be off by a tooth, but it is more likely that an "experienced" mechanic used the wrong thickness spacer at the bottom of the jug causing the cam to be off by a few degrees. There are different sized spacers depending on what head is used. Missing a tooth would put your timing off by many degrees, the wrong sized spacer would put if off by a few degrees...enough to make it run like crap.

I haven't done a tooth count (anybody know what it is?) but its a small cam so lets say that it has 36 teeth. If you are one tooth off your timing will be off by 10 degrees. I don't see it even starting being off that much.
Uh,

One tooth of a 36 tooth cam sprocket is five degrees since two turns of crank for one turn of cam.....and, they will run very well if retarded.....and they run out of power as RPM gets higher.

It doesn't really matter.....the cam tooth count is always double the crank tooth count.

Rob

Not disagreeing and as I said the first thing I would check is the cam setting. Good catch on the cam count double the crank count. No matter what it sounds like timing is off

Posted: **Tue Sep 04, 2012 2:25 pm**

You can check the timing yourself with an 8mm socket and a screw driver.

Posted: **Tue Sep 04, 2012 9:42 pm**

Or with a timing light. It really should have been set up right by the installer.

Posted: **Fri Sep 07, 2012 10:19 pm**

Hello Buddy Land:

Anyone actually installed this Big Bore 161CC kit stand alone and got improved power and or speed?

Rick71454

Posted: **Fri Sep 07, 2012 10:50 pm**

rick71454 wrote:Hello Buddy Land:

Anyone actually installed this Big Bore 161CC kit stand alone and got improved power and or speed?

Rick71454

Yes, I have about 550 miles on the kit. I jetted the kit to a 110 main and it was too much and caused it to misfire. Jetted down to a 105 and rain okay averaged about 50mpg for 500 miles. It was immediately able to pull the front tire off the ground. To wheelie all I have to do is scoot back on the seat and hold on. Stronger torque in the low and midrange. It felt stock after 30 mph. Top speed was unchanged. 2 weeks ago I jetted down to a 105 and picked up power everywhere. It pulls strongly to 40 mph. I picked up 2-3mph up topend. Top speed is about 62 mph indicated. I, 6' and 255lbs.

Your scooter should feel exactly the same, just stronger. The stock cylinder head will limit power in the top of the rev range.

Posted: **Sat Sep 08, 2012 12:22 am**

rick71454 wrote:Hello Buddy Land:

Anyone actually installed this Big Bore 161CC kit stand alone and got improved power and or speed?

Rick71454

Yes. Also did air box mod and upped to a larger carb with an NCY pipe. As said above it kicks butt off the line!

Posted: **Sat Sep 08, 2012 2:46 am**

Hello BuddyRaton;Lovemysan:

Thanks for sharing your own experience with the Big Bore Kit.
Yours is what I expected.

I have my scooter in for a second opinion with another shop. As a preliminary diagnosis, he thinks the piston might be installed backwards. In such as case, not enough oil lubricates the piston motion and it bogs down to like from 60MPH to 40 MPH.

What do you think of this idea?

Rick71454

Posted: **Sun Sep 09, 2012 12:33 am**

rick71454 wrote:Hello BuddyRaton;Lovemysan:

Thanks for sharing your own experience with the Big Bore Kit.
Yours is what I expected.

I have my scooter in for a second opinion with another shop. As a preliminary diagnosis, he thinks the piston might be installed backwards. In such as case, not enough oil lubricates the piston motion and it bogs down to like from 60MPH to 40 MPH.

What do you think of this idea?

Rick71454

Posted: **Tue Sep 11, 2012 3:07 am**

Hello monamibuddy:

Did you intend to send me some comments in your post yesterday, because there was none?

Thanks
Rick71454

Posted: **Tue Sep 11, 2012 5:17 pm**

Hello Buddyland:

I got my Buddy 125 back from the second mechanic. He found and confirmed that the original shop that worked on installing the Prima Big Bore Kit 161cc, had put the piston in backwards. The orientation arrow is suppose to point toward the exhaust port, not away from it.

Major major mechanic work error as such it likely damaged the engine due to the lack of oil lubrication, resultant friction, and lower speed of the engine. Bad mistake..................

Now, the scooter runs with increased strenght and speed off the starting block. Current top speed still only at 61 MPH indicated just slightly faster than with stock engine. Proof that a Big Bore Kit stand alone installed without other additiional mechanical upgrades does work.

How do you others get your Buddy 125 to go 75MPH and faster other than to weigh only 95 LBS and tuck?

Rick71454

Posted: **Tue Sep 11, 2012 6:39 pm**

Sounds like normal to me. After the big bore kit my scooters gps confirmed top speed is 52 mph, 63 indicated. If you're a big guy that's about all you'll get. You could play with cam, head and carb tuning to get more but there is no magic pill. I don't see how puting the piston in backwards could cause an oiling issue, I thought it was all splash oiled. Ive seen pictures on wrings put in backwards with no I'll complaints.

Posted: **Tue Sep 11, 2012 8:21 pm**

Hello lovemysan:

Thanks for your response. You are correct that the engine parts splash the oil inside a scooter engine. A car has an oil pump to move the oil around. I am not sure if piston rings backwards, or if there is such a thing makes much difference. A piston has little holes and canals where the oil flows through it to the cyclinder walls. With a backwards piston, that flow does not work so well. As such less oil flowing, more friction, more engine wear, slower speed.

Rick71454

Posted: **Wed Sep 12, 2012 1:57 am**

Sounds like the first mechanic was not competent.

Posted: **Wed Sep 12, 2012 3:24 am**

Good catch by the second mechanic. Really stupid mistake by the first. every arrow I have seen on a scooter piston points to the exhaust

Posted: **Wed Sep 12, 2012 4:45 am**

rick71454 wrote:Now, the scooter runs with increased strenght and speed off the starting block. Current top speed still only at 61 MPH indicated just slightly faster than with stock engine. Proof that a Big Bore Kit stand alone installed without other additiional mechanical upgrades does work.

I'm not sure that's proof of anything.

You say the first install likely damaged the engine. What did the second mechanics do? Replace the entire top end? Or just re-install? Were all the same parts used? Your cylinder, piston and rings are surely not in the shape they were when you bought the kit.

A cylinder kit needs to be broken in exactly as you would a new engine. And as with a new engine, performance will increase over time.

But plenty of others have done the install, had it done right the first time, and gotten good results.

Posted: **Wed Sep 12, 2012 9:53 pm**

Hello BuddyRaton:
Yes, stupid mistake by first mechanic shop.

Hello Lovemysan:
Yes, at least questionable competance by first mechanic shop.

Hello ericalm:
The second mechanic reoriented the piston so the direction arrow on it point in the right direction which is the exhaust port. That meant removing the cyclinder head after the first mechanic installed the piston facing the wrong way. I agree with the break period you mentioned and I hope it goes faster later.

Posted: **Mon Sep 17, 2012 5:52 pm**

I have 2 questions about this:

1. Does the 161cc Big Bore Kit change the power curve, necessitating different roller weights?

2. Can I use a stock 170i exhaust instead of the Prima 125 high performance exhaust to try and keep the volume down?

Posted: **Mon Sep 17, 2012 7:46 pm**

Rusty Shackleford wrote:I have 2 questions about this:

1. Does the 161cc Big Bore Kit change the power curve, necessitating different roller weights?

Yes and no. It does alter the power curve, but I wouldn't change weights from the start. You'll get better acceleration and power uphill, etc. — an all around stronger, if not necessarily "faster" engine. I'd wait until it's broken in, maybe 800+ miles on the kit, before making other changes. Otherwise, it's difficult to know exactly what changes in behavior are due to one or the other. Changing rollers is a bit of a trial and error process to find your personal sweet spot, so best to do it when you'll have consistent results to use for comparison.

2. Can I use a stock 170i exhaust instead of the Prima 125 high performance exhaust to try and keep the volume down?

No, but you can use a stock 125/150 exhaust. It'll still be louder/ "chunkier" than bone stock and will NEVER be as quiet or smooth as an injected scooter, though.

Posted: **Wed Sep 19, 2012 6:38 pm**

Hello ericalm;Rusty Shackleford:

I agree entirely with what ericalm wrote in their response about power curve and roller weights. I got about 600 miles on my new 161cc Big Bore kit. I am preparing to change to heavier roller wieghts do it myself. I have the Prima set of roller weights from 6g to 17g with 3 per same size. Stock roller wieghts in the Buddy 125 are 11g. I might jump to 3 of the 15g, keep the other stock 11g, and see what happens trial and error from that point.

rick71454

Posted: **Thu Sep 20, 2012 7:42 pm**

That is a really big jump in roller weights (78g vs. 66g). Since changing rollers only takes a couple minutes, I would start with a smaller gap (maybe 3x11g and 3x13g) and see how that works out.

Are the ramp lengths in your variator all the same, or are there two different ramp lengths/profiles? If you have a short ramp and a long ramp, go with the heavier weights in the short ramp so they come in sooner. If the ramps are symmetrical, just be sure to keep the different weights evenly spaced.

Use the sharpie method to see how high your drive belt is getting on the variator pulley. Once your marks are 2-3mm from the top of the pulley, you have pretty much maxed out the effective gear ratio of the front pulley and using heavier weights will not result in higher top speeds (but will effect acceleration and engine RPM's negatively).

Posted: **Thu Sep 20, 2012 9:22 pm**

Hello thatvwbusguy:

Thanks for your advice.

I have alread taken the kick starter and transmission cover off to watch with the CVT transmission work. As I move the throttle, I can see the drive belt around the variator pulley move out to the larger diameter. When I bring the throttle back to idle position, the drive belt moves to a smaller diameter.

I am thinking with my Big Bore Kit 161cc recently installed, it would handle that jump from 66g to 78g fine due to the increase in torque............. Stay tuned.

rick71454

Modern Buddy

Buddy 125 upgrade to Prima 161 Big Bore Kit

Buddy 125 upgrade to Prima 161 Big Bore Kit

Re: Buddy 125 upgrade to Prima 161 Big Bore Kit

Re: Buddy 125 upgrade to Prima 161 Big Bore Kit

Re: Buddy 125 upgrade to Prima 161 Big Bore Kit