Modern Buddy

I took a road trip from Galveston, TX area to Dallas, TX area a couple of weeks ago and really enjoyed myself riding 60-65 mph on state highways (EDIT: not interstates) with my 2007 Buddy 125 (upgraded to 162cc). I took the back way through East TX and it was beautiful. On the way up there, I experienced more of the engine hesitations I talked about in these threads but it didn't seem like a big deal:

http://www.modernbuddy.com/forum/topic31780.html
http://www.modernbuddy.com/forum/viewtopic.php?t=31798

I wasn't too concerned until I left Dallas to go back home and about an hour into the trip the scoot started sputtering and backfiring like crazy. It was getting late, and the parts stores were closed so I couldn't get Seafoam. Instead, I got some STP fuel cleaner from a gas station which didn't help. Loosening the gas cap didn't help either. So I turned back, and had a motorcycle shop in Dallas area called 5 Star Cycles look at it.

The shop cleaned the carb and also said it was totally out of oil. Oops. I feel pretty embarrassed about the oil because I should have checked that before I left. With a cleaned carb and oil it ran much better. So I got on the road again but it died about 3 hours into the trip home! First, it started the hesitations again. Then, I stopped and checked the oil (learned my lesson!) but it was full. Next, the engine just cutoff completely while on the highway at 55 mph. I tried to start it, and found it would only stay running for about 15 seconds.

I called Scootersmith shop here in Houston today. They are the shop that the previous owner used and are the ones who converted it to 162cc. He said that even scooters that are 162cc shouldn't be driven on the highway because you are basically redlining it for hours on end. He says it's possible there was serious engine damage from me riding it on the highway on a road trip. He says if engine damage turns out to be the case after they look at it, they may be able to replace the top end or whatever was damaged.

I guess I'm sort of surprised. I thought people did road trips on these things sometimes. I guess he's probably right, but if that's true I feel double stupid for destroying my scooter. Do you think he's right? If only someone had told me this when I bought it, lol. Sigh.

Did your scooter get re-jetted after it got the 162cc BBK? Has anyone looked at the spark plug recently to see if you are running lean? Running out of oil could have damaged the engine and/or you could be running too lean.


There is a chance the stator went bad, but only a small chance.

A Stock Buddy 125 can run full throttle all day. Modified ones can too but they need to be tuned properly. If you were having engine issues you probably shouldn't have gone out and rode full throttle for hours on end. Also, before going on a long ride you should check your oil, I check mine before any ride over 200 miles. It is also good to check it every few weeks along with the pressure in your tires.

scootERIK wrote:Did your scooter get re-jetted after it got the 162cc BBK? Has anyone looked at the spark plug recently to see if you are running lean? Running out of oil could have damaged the engine and/or you could be running too lean.


There is a chance the stator went bad, but only a small chance.

A Stock Buddy 125 can run full throttle all day. Modified ones can too but they need to be tuned properly. If you were having engine issues you probably shouldn't have gone out and rode full throttle for hours on end. Also, before going on a long ride you should check your oil, I check mine before any ride over 200 miles. It is also good to check it every few weeks along with the pressure in your tires.

I don't know what re-jetting is but will ask the shop about whether it was done when they did the conversion. The spark plug sounds like a good thing to check, thanks. I hope the engine having no oil didn't damage it but agree this could be the issue. I'm definitely flogging myself for that.

The most interesting part of your comment though is that they can run full throttle all day. What the guy at the shop said contradicts that, but I tend to side with you. What sort of special tuning does a modified one need? Thanks!

Re-jetting means putting new jets of a different size in your carburetor. It would be done after converting to a bigger engine because now there is a bigger cylinder to fill. If you're still using the jets that were meant for a smaller space, you're not pulling as much fuel into that space as you should be (lean condition), so usually you get a bigger jet. Think of it like a thicker straw.

On the oil front, I think you're likely not pulling in enough for a different reason. At least on the Buddy 50, the oil is distributed based on a fixed gear into the engine - the faster it spins the more oil gets delivered, but its a fixed ratio. If you make the cylinder bigger you probably need a bit more oil, but that's impossible because it's still on the old fixed ratio which is calibrated for a smaller cylinder.

I'm actually not sure if this second point applies because I think the 125 has a different oil system, but I've never owned one so who knows.

I had a bbk kit on my Zuma 125. Outside of using a small bit of oil between changes, the motor was rock solid and super reliable. I beat the poop outta that scooter, long WOT runs included. So I suspect your motor wasnt set-up 100%. I did silly long WOT runs on both of my stock Buddy 125's and neither one ever missed a beat. I gave a friend a Buddy 150 engine to save him time and money, instead of doing a bbk kit on his 40,000 mile 125 motor. I rarely mess with motors anymore and honestly dont wanna split the case on the 125 and go thru the whole thing with him. Swapping to a bigger stock engine just seems easier.....

People do take these on long road trips, but they are mostly taking backroads, not interstate highway. Redlining it with poor jetting wouldn't have taken three hours to cook the top end, it would have happened much sooner. Your bike does have an oil pump and a filter, and any oil starvation could have led to serious damage.

I tend to worry about the big bore kits for extended full throttle runs, because the cooling fins are the same size as stock, the fan is still the stock size, and now you have more power and to my mind, more heat. If the engine got too hot on a long stretch, I can also see it doing damage and causing blowby.

All this is to say, I hope it won't be too expensive a repair, and try to avoid the highway going forward.

Could be your stator going bad. Everyone always first thinks it's a fuel delivery problem.

Stanza wrote:People do take these on long road trips, but they are mostly taking backroads, not interstate highway. Redlining it with poor jetting wouldn't have taken three hours to cook the top end, it would have happened much sooner. Your bike does have an oil pump and a filter, and any oil starvation could have led to serious damage.

I tend to worry about the big bore kits for extended full throttle runs, because the cooling fins are the same size as stock, the fan is still the stock size, and now you have more power and to my mind, more heat. If the engine got too hot on a long stretch, I can also see it doing damage and causing blowby.

All this is to say, I hope it won't be too expensive a repair, and try to avoid the highway going forward.

Thanks! Hmm, interesting about the possibility of overheating.

Also, I only rode on state highways, never interstates.

Well first, what happened to ALL the oil in the crankcase? Why would a Buddy use all that oil in a few days? Our Buddy is over 10 years old and does not require adding oil between changes. You might check the compression to see if that is the oil explanation. Second (and I know some others will disagree with me), putting the larger cylinder kit on the Buddy 125 puts more strain on the engine and adds more heat at speed. You shouldn't be surprised if that reduces reliability/longevity. The bigger Buddys (150/170) have an oil cooler installed at the factory which the 125 does not have. That also tells you something about engine cooling with the larger displacement.

I second k1dudes suggestion of a failing stator. When the stator starts to go power to the spark plug is weak and inconsistent which can cause a number of poor running symptoms.

I had the stator on my 2007 Buddy 125 fail and your description, particularly the engine hesitating, intermittently cutoff completely and then restarting only to run for about 15 seconds sounds very similar to when mine failed.

Definitely sounds like a stator issue, and the oil loss could either be a leak, or poorly seated rings (was it broken in properly?).... or it wasn't filled it up properly to begin with.

Two things you can do to improve cooling: Get an NCY fan and rotate that air intake cover 90 degrees to turn it into a scoop. (you'll only have two screws holding it on, but that's OK)


And ride your scooter where and how you want - it's a 2007, so it's not like you invested a ton of cash into it.

Thanks everyone for the replies. I just got it back from Scootersmith and it's running great. They replaced the stator, just like some of you guessed. So I guess I'm out of the woods (of East TX?) but will keep an eye on my oil to see if there is an issue there.

I'm still on the fence as to whether is a bad thing for me to drive it 65 mph, so let me know if any more of you have thoughts on my state highway (not interstate) driving.

Cool deal and back on the road! Anyways, just make it a habit to check the oil now. I got lazy and finally checked the oil on my Liberty and it was very low, like barely showing on the very tip of the oil stick. So I got a lesson in topping it up because the oil fill hole is silly tiny. My scooter has a low oil light and luckily I've never seen it come on. I dont do WOT runs on the Liberty, maybe a short blast thru a tunnel or to mess with someone. The poor thing has its work cut out enough hauling 2 up everywhere!

soup wrote:Thanks everyone for the replies. I just got it back from Scootersmith and it's running great. They replaced the stator, just like some of you guessed.

That's great! So glad our members could help.

Happy Scootering!!!

Glad it's running! The missing oil bit is really striking to me. That seems like a red flag. Did you go really long without checking the oil? I'd make sure that the oil filter and drain plug are snug. The filters have to be fairly tight on these bikes, otherwise they self-loosen and leak. I'd also take a paper towel under the engine and see if there was any drip spots... maybe there is another loss pathway.

I have been running a 161 kit for quite some time with an upsized carb with no problems.

I lived in Texas and the state roads are just as fast as the interstate. I have ridden mine long distances but not WFO all day. I back off the throttle maybe 5 mph so run at about 60 mph with a ton more torque

Also if I know it's going to be hot I pull the plastic in front of the valve cover for more air flow.

The stator does apperar to be a weak point on older Buddys especially 07 to 09.

Glad everything worked out for you!