Vintage Dirt Bike Q & A

Hey guys, I got my transmission and crankcases back together tonight. I was shifting through the gears with it on top of the work bench and it seems to bind up when shifting into 4th and 5th and then back down. I split the cases again and it looks like 3rd gear is not engaging with 4th on the mainshaft, the three prongs on 3rd are pushing on the 4th gear instead of fitting down in the slots of 4th. It takes some force but if I twist the main shaft and counter shaft in oposite directions the gear falls in the slots and engages like it should. I have 3 manuals and the parts list that I followed when putting it back together so I believe everything is correct. Is this normal and the gears will slide into place properly when the engine is running or is there something wrong. Any help will be appreaciated.

Thanks,
Matt

Matt:

I have found the same problem without oil in the case. Did you have oil in there?

Lee

No I didnt have oil in the case, also the clutch and kick starter gear were not on would this make a difference.

Matt

I believe this is normal for an engine that isn't running and/or a bike that is standing still. If it were rolling the gears would be rotating and mesh as soon as they line up.

I was rotating the mainshaft while I was shifting gears, so it should line up the gears as it rotates.

Matt

I encounterd this same issue 2 weeks ago. The oil in the gearbox seems to be the cause because when I buttoned it up the shifting was slick. You need to turn the main shaft a lot to get these to mesh easily but without oil they tend to bind.

I think we all have been amazed by the fact OIL counts! How many times have you looked at the thrust washers thinking DID I PUT THEM IN RIGHT!
Just to find out after the oil was in the problem went away. It never tells you anything like this in a Clymer or Hayes book.

Live and learn.

Lee

Well I guess I'll put it back together tonight and hope for the best. I've heard that the transmissions are prone to break on the 73 and 74 Elsinores. Is there any way to prevent this or signs of it starting to go.


Thanks for the help,
Matt

It was pretty common that the 73-74 CR250 transmission gears failed. I switched over to a 1975 CR250 transmission which bolted right in & problem solved. Shifts nice!!

I think there is a way to modify your 73-74 gears which makes them better (is it called die cut?).

Good Luck

Small world. Let my S.O.'s little brother ride my MT250 and after beating it he came back saying he thought the clutch was slipping. Next one to ride it was my son-in-law a few months latter, yes I mainly wrench and only ride once or twice a month if that often during the winter. He came back and said "No second gear" so I got on it and sure 'nuff nothing there.

It was a used '74 transmission but looked ok when I put it in. I will keep an eye out for 1975 parts.

Well after the hard drive crash so I thought I might get the ball rolling.

Just picked up a used 1976 MT wide ratio transmission for my bike off eBay for $52.

Two things worth mentioning are it is local so no shipping fees and it comes packed inside a 1976 MT. Bike is terribly bent, looks like someone ran it into a wall at speed. The only thing missing are the tail light and turn signals.