Modern Buddy

Hey Folks,
I got a Buddy 150 today that had been sitting for a while. I cleaned the gas tank and carb, fresh gas and new battery and it feels like it just has low compression. bummer!! There is spark.
I'll test the compression valve clearance tomorrow; but i know what low compression feels like.

Question: If I have to do the top end job on it, what is the recommended kit to get? I don't necessarily want to go bigger; just a reasonable price.
Secondly, do I have to take the motor out or can I get away with pulling the head/cylinder while the motor is still in the bike?

Appreciate your feedback!

Thanks!

If it ran more or less properly before it was put away, the low compression could be as simple as sticking/corroded valves and/or lazy rings. You might consider a squirt or two of Marvel Mystery Oil down the spark plug hole overnight, and a shot or two of it in the fuel tank (with fresh fuel, of course). If you can get it started, sometimes the heat, oil, and engine cycling smooths out the schmutz without much additional work.

Above is a great start! Also, do 2, or even 3, compression checks to make sure you get a repeatable number. If it is low definitely try the above before tearing into it. Now if the compression number is within spec I bet a torque driver is dried out and sticking, causing the belt to be in the wrong "gear". Please keep us posted on your findings.

I've never pulled a motor out of a Buddy, but if needed it can't be that hard if you have the space and tools. I've done rocket bikes, Zuma 125, vintage Vespa, Lambretta and a Honda Silverwing and none of them were that bad to pull the motor from. I do recall the first time I had to disconnect a EFI line. I've since purchased a fuel hose tool kit!

Here are some clarifications:

Got the bike as it ran when parked, and they tried to clean the carb - I really doubt that's true actually...

the gas in the tank was varnish...that is why I took it out and thoroughly cleaned it with ethanol free gas.

Today I checked the valve, the intake was way too loose, just moving freely, the exhaust was also way out of speck. Put them both to .76mm. Checked the compression...nothing. Not much movement on the meter. Then I loosen the oil dip stick while compression tester still attached and oil spurted out of the filler hole upon crank - that's BAD right?

fijiman wrote: ↑Sat May 03, 2025 2:47 am Then I loosen the oil dip stick while compression tester still attached and oil spurted out of the filler hole upon crank - that's BAD right?

I might be wrong but I don't think that's a bad thing. If you crank over a properly running Buddy 125/150/170 with the dipstick out it will shoot oil out. If you start the scooter with the dipstick out it will spray oil all of the place, easily 6-8 feet, I accidentally did it once and learned my lesson.

You're right, I was thinking about compression testing the cylinder.
I'll do the Mistry oil treatment and repot back the results.

Question: Can I use seafoam instead of mystery oil, I have some of that laying around.

You're better off with MMM. If you do go with seafoom,mix 50/50 with 2 stroke oil.

Seafoam is - to the best of my descriptive abilities - a solvent. (I have my doubts that it does much of anything, anywhere.)

Marvel Mystery Oil is a light lubricant.

How many miles in the engine?

I pulled my Pamplona's engine to do a top end swap. I don't believe you have enough space between the frame braces to remove the top end in-situ.

Check Amazon for a cheap borescope before disassembling anything. It's well worth it to know that you're dealing with before teardown.

You may just need to pull the head, decarbonize things and lap in the valves for better sealing.

I have a sub-13K top end that came off a running engine that you're welcome to if it comes to that. I went ham on an NCY 61mm big bore with big valve head and performance cam. Getting everything running correctly was not plug 'n play. Unless you really want a big-bore Buddy, I'd advise staying close to stock.

Thanks everyone for your help...someone ended up making an offer on the scooter and I got if off my hands..