Modern Buddy

Hello all -

I've done everything I can on the carburetor. I've verified it's operating properly with the diaphragm and the jets/float seem to be clean and clear. The engine will turn over, RUN for 2 or 3 seconds (sometimes) and then just die. I couldn't add throttle because it would immediately die. Restarting right after, it will catch, turn over, and die.

One thing I did not mention, was the owner of the scoot who I am fixing it up, said that after the Buddy died on him, he checked the oil level, and it was empty. He added oil to it. I was puzzled to that, as when I checked the oil myself, it was black, and not fresh. I did the fingertip compression test, and a good puff of air was felt as I pressed the starter.

My next question is, would a engine who had imploded due to lack of oil be able to start at all? Would it turn over and run for a few seconds?[/b]

Go borrow a compression tester from your local AutoZone with their Loan-A-Tool program. Connect it to the spark plug hole and zero the dial. Leave the kill switch off, open the throttle and run the starter for a few seconds.

Check the gauge dial; you should see a reading between 110psi and 140psi. If the reading is 90psi or less, the rings are shot and/or the cylinder is scored and it's not building enough compression to run.

I still suspect that your issue is fuelling, but this test will tell us if the engine can at least build enough compression to run.

Ya that should be my last thing to try before I bring it to the dealer to have a look at it.

Dumb question - what size for the inlet on the pressure tester?
(What size for the spark plug threads?)

Spark plug hole has 10mm threads.

So here's an update -

Brought the Buddy to the dealer ( Carlisle Cycle and Scooter ) he put it on his lift and checked everything. Turns out the variator when separated from the belt, spun very smoothly. Apparently that isn't supposed to happen. He said that it indicated to him that the crank bearings were toast. That would explain why it would start, run a few seconds and then just give up.

Thought you guys would like to know what happened.

Kaboom! Yep, oil is important.

I smell bad half open reeds.

You may also have air leaks if its a 2t model

125 is a 4t

dasscooter wrote:125 is a 4t

Timing is off or chain has slack, in certain cases if when you engage clutch and it stalls then your clutch is burnt out causing binding.

RoaringTodd wrote:So here's an update -

Brought the Buddy to the dealer ( Carlisle Cycle and Scooter ) he put it on his lift and checked everything. Turns out the variator when separated from the belt, spun very smoothly. Apparently that isn't supposed to happen. He said that it indicated to him that the crank bearings were toast. That would explain why it would start, run a few seconds and then just give up.

Thought you guys would like to know what happened.

Ok, something doesn't sound right about that. Firstly, the crank bearings have nothing to do with the variator spinning freely since it (the variator) is not directly attached to said bearings. The bearings support the crankshaft and that's it. The variator is attached to the end of the crankshaft via splines and a big nut so should not spin freely even with the belt removed. On top of that, there is still going to be drag coming from the timing chain/camshaft/valve springs connection. Now, if the piston rings are bad (due to wear or breakage), then it would be possible to easily turn the variator by hand, along with the crankshaft/connecting rod/piston/cam/etc, even with the sparkplug in place. But, it still wouldn't just spin freely. Even bad rings offer some drag on the up and down movement of the piston.
I'd ask your mechanic for a better explaination and/or do a compression test. An engine with very low compression would exhibit the symptom you described.