My buddy bought an 1983 FL250 which I’ve been handed the responsibility of trying to get it to run and when we picked it up the wheels wouldn’t even budge. The seller claimed that it drove to its last spot where it sat at for many years until the day we picked it up. I highly doubted that claim… what do you guys think it could be? I’m fearing the worst case scenario. I’ve disconnected both braking systems to count out possibly of brakes being locked up. Could the motor (( Internal Combustion Engine ? ))/piston be seized? Or possibly transmission related? I assumed even if the clutch went out it would still roll, would it not?

If you have disconnected the brakes and removed the belt then my money says the transmission chain has piled up inside or all the oil leaked out and the chain rusted up.
Here is a link to a free manual you can download if you don't have one.
https://oddatv.com/fl250-fl350-factory-manuals/
(Link is near the bottom of that page)
I also am including the parts fiche for download.
CO

This site is now almost ded.
Most members have got old or just left.
So you will have to wait for answers and check for a few days to see if anyone replied.
There is still an incredible amount of info on this site.
Just use the search box to find what you are looking for.
In the search box type ONE word ONLY and hit enter. If you don't you will get to many hits.
When the list of threads comes up there will be another search box there on the right.
In that box type ONE word ONLY. Keep doing this as many times as you want until you have narrowed it down. Some common words will be ignored like "Engine" "Honda" etc.
Also at the very bottom of any thread you read will be an area where there a similar threads to the one you are reading. You can click on them to read.
CO

Edit: This ain't fagbook so answers are accurate and to the point but you will have to wait for a reply due to very few members showing up now.
CO

Here is some more reading for you.
viewtopic.php?f=1&t=10532
http://www.pilotodyssey.com/250trans.htm
CO

Thank you for the info. So I took the reduction case er tranny apart to find nothing is wrong with it. So does this mean the worst case scenario of the piston being seized up? Could it just be rusted stuck or is the motor (( Internal Combustion Engine ? )) likely a goner and no hope of it ever running again?

"So does this mean the worst case scenario of the piston being seized up? Could it just be rusted stuck or is the motor (( Internal Combustion Engine ? )) (( Internal Combustion Engine ? )) likely a goner and no hope of it ever running again?"

Since you took the transmission apart it's apparent you have mechanical skills.
No Engine is a "goner". It can all be repaired.

You say the tranny is good but I thought you said that the brakes were released and took the belt off the Engine ?
Did you use the pull start to see if the Engine turns over before you started removing the tranny ?
You may have released the brakes on the adjustments but they may not have backed off and just rusted in place after all these years.
It could also be rusted up bearings on an axle.
CO

Edit:
From what I'm reading I would do a complete re&re on this machine.
If you don't then you won't know what you got.
CO

Maybe I missed something here? Even if the Engine was seized the buggy would still roll. The belt will allow the wheels to turn without turning the Engine. Now if the clutch was somehow holding the belt, that would make it very difficult to roll the buggy, even with a working Engine.

If you have the tranny apart, I assume you have the belt off, if the wheels still won’t turn, there is no belt connecting the tranny to the Engine, so it would seem to me the axle not turning has nothing to do with the Engine.

Like CO said above, see if the Engine turns over with the belt off, then check the other things he mentioned, like brakes, bearings, and transmissions. My guess is the brakes are seized up.

All 4 tires locked up or just the rear

If just the rear is locked you check if the caliper is stuck or the E-Brake is stuck?

Yes that is correct. I found the tranny internals and chain to be working just fine. Once I removed the drive belt I was able to determine that the tranny was not the cause of lockup and neither the brakes. Completely disassembling both braking systems was the very first thing I had done.

About the pull start, it would not turn the motor (( Internal Combustion Engine ? )) at all, rope would not come out or budge but when I removed the recoil starter assembly and then pulled on the rope it moves freely and I can see the 3 ratcheting teeth functioning properly.

About the axle, I completely removed it when pulling the tranny so rusted bearings isn’t it either. I should also mention that when I first found the rear wheels to be locked up it was due to the drive belt still being connected. Once drive belt came off the rear wheel lockup was not the main issue.

I did remove the top of the cyl head and found slight rust on piston. I doused it with PB Blaster and gently tapped on it getting it to break free/budge about 1/8” or maybe just 1/16” but with the cyl head removed, piston exposed, I still can’t get the crankshaft to fully rotate. I’ve tried excessive force but fearing I’ll break something or perhaps I didn’t use enough force. Not sure what to do at this point.



As I’ve mentioned in my previous response to CO, I’ve determined that the wheels being locked up was due to the drive belt still being connected. Once that came off during my removal & disassembly of the tranny I found that the wheels now spin but the underlying issue is something inside the Engine. I cannot seem to get the motor (( Internal Combustion Engine ? )) to turn. This is beginning to drive me nuts trying to figure this out.

Here’s an update on my latest progress…

I was able to get the flywheel/clutch to rock back n forth enough for the piston to travel up n down nearly 1/2”. But what could cause the travel to abruptly stop /lockup preventing complete rotation of the crank?

STOP !!!

It's possible the piston has a broken ring and it's snagging a port when you try to move it.
You have to be careful here or you will badly damage the cylinder.

I hate to tell you but that entire Engine will have to be disassembled and rebuilt.
Patience is needed here.
CO

Have to agree with C/O here, there are other possibilities, but piston ring or piston land damage sounds likely. Any chance the starter bendix is stuck out, jamming the flywheel?

Well fellas… here’s what’s going on as of lately. I made 2 short videos so you guys can actually see and hopefully identify something I haven’t. The first video is of the cylinder head being moved up and down since I couldn’t actually move the crankshaft and piston itself. This was to show that it couldn’t be the rings being caught on anything. The second video is of the tiny bit of movement when I turn the crank back n forth. I’m completely stumped guys. The reason I pulled the cyl head off this way is because I had to order a special tool to remove the clutch and it hasn’t arrived yet. So this was the next best route to try and uncover the culprit.

1st video:
https://flic.kr/p/2oJzJc2

2nd video:
https://flic.kr/p/2oJyyCy

Ok, C/O is gonna be way more help here than me, he’s rebuilt a bunch of these, I’ve only done top end work, and it’s been decades. One thing I can say is, it’s possible something like a rock, or a nut or bolt could have made it through the intake into the bottom end, or maybe an issue with the counter balance?

I assume the cylinder came off with no resistance or you would have mentioned it, that would likely rule out broken pieces of piston or rings falling into the bottom end.

I guess the roller bearing for the rod or crank could have come apart? At this point it looks like you’re committed to having to split the case, so you will find the culprit one way or the other.

I’m sorry man, disregard everything I’ve said, I was thinking Fl350 not 250. Sometimes in trying to help I just get in the way.

Looking at those videos it just screams "Piled up crankshaft bearing".
One of the bearings on the crankshaft most likely came apart.
Just my opinion.
CO

Maybe a magnet came off of the flywheel and is jamming it up. Something in the bottom end or a bad bearing.
Otherwise, not a lot to go wrong with a simple 2 stroke like the FL250.

That is correct, I felt no abnormal resistance while lifting the head entirely off of the piston.
Also correct, if I wasn’t fully committed before, I sure am now. Lol. Y’know, it’s kind of funny that when I first began troubleshooting this, I never actually thought it would lead to full blown labor. I thought taking on this project was gonna be easy, quick and fun. Lol. Now I’m just determined to finish what’s been started.

I had a ton of fun with a few different 250’s when you get bored with it, find a 350 or a pilot. It’s a life style..lol

One of the first things I did was check the entire electrical system since the factory harness was compromised so I completely remade a new one. I also checked the stator and did the 3 component tests mentioned in the manual. I found that the exciter coil needed replacing. Having to pull the magneto off at this time, I can confirm it is in good shape.



I’ve never experienced a crankshaft failure of this kind before so I’m still trying to wrap my head around it. I’m eager to see it up close. But after everything we’ve uncovered so far, this must be it.

Pull that Engine and split the cases so you can see what’s going on. Pictures would be nice once you get the Engine apart.

I would plan a total rebuild. FL250 parts should available.

Yes I definitely planning on doing a complete rebuild. I’m gonna speak with the owner and discuss this with him. Sourcing the parts I’ll need is going to be the most difficult thing for me. I’ve already done a quick search and can’t find anything like bearings. If anyone knows of any sources or leads please lmk. I decided when doing the rebuild and when I crack the case open finding the main culprit for this rebuild I’ll take photos to share on here in case anyone else ends up needing to do the same in future for their fl250.

Parts:
The crank bearings on an FL250 are just your standard 6306 bearing. You should be able to get these at a place like NAPA or some other automotive place. I don't know where you live but I get my bearings and seals at BCbearing here in canada or at NAPA.
You can get the 6306 2RS bearing as well. The 2RS just means it has a seal on each side but you remove those with a pick. They come out very easily. It's the most common type.
I would also browse OddATV for other parts or seals https://oddatv.com/product-category/fl250-new/

Since you took the Engine apart without leak testing it first, you now don't know if the crank seals are good or not. You could gamble and hope they are ok or you can replace them. Since you are in the states you could also try Colonial seals. They used to have a great website where you could type in the number of the seal you want and it would tell you if they got it. Now it's no longer on their site so this is a bummer. Now you have to phone. https://colonialseal.com/

When your Engine is back together you WILL have to leak test it.
Here is a video of it being done to a FL400 Pilot Engine. https://www.youtube.com/watch?v=zdq7NRcUIp8
Please note that these guys forgot to tell you that your piston MUST be in the down position so that the ports are open.
I think the guys here might lynch me for posting them guys. LOL.
Here is a great read from Klemmvintage. These guys really know their stuff. http://www.klemmvintage.com/airleaks.htm
CO

Edit: Please note that I posted a parts book for you to download earlier in this thread and all of the numbers are there for you to use. Not sure if you downloaded it.
CO