YZ250F (1979) Transmission Problem

[ats666]

I also have a 79 yz250.

Yamaha wanted $75 for each thrust bearing!!! I said screw that.
This last winter I replaced my swing arm bearings and lower chain roller with the allballs kit.
I drilled and installed grease nipples in the swingarm so I wont have to touch it again in along time.
Make sure to get the swing arm protector (so the chain doesn't chew the metal casing and the rubber seal)


My bike does not have an upper chain roller and I cant seem to picture where it would be. Any chance you can get a close up picture for me so I can see it???

If you get in a jam and cant find parts on ebay or through yamaha then just message me (I have collected some spare parts over the years)

 

[whenfoxforks-ruled]

The old 2 bolt oil drains got yet another? I know Suzuki states that both have to be pulled. Never knew Yamaha's had this setup also. One of the funniest threads was trying to tell a guy which hole it belongs in. Stupid online micro fiches are priceless. Just the swingarm bearings, man did you find a steal! Nice bikes.

 

[BadgerMan]

I also have a 79 yz250.

Yamaha wanted $75 for each thrust bearing!!! I said screw that.
This last winter I replaced my swing arm bearings and lower chain roller with the allballs kit.
I drilled and installed grease nipples in the swingarm so I wont have to touch it again in along time.
Make sure to get the swing arm protector (so the chain doesn't chew the metal casing and the rubber seal)


My bike does not have an upper chain roller and I cant seem to picture where it would be. Any chance you can get a close up picture for me so I can see it???

If you get in a jam and cant find parts on ebay or through yamaha then just message me (I have collected some spare parts over the years)

My bike does not have a swingarm protector/chain slider and it looks like it should. The parts fiche does not show one that I can see. Where can I buy one....OEM or aftermarket?

 

[whenfoxforks-ruled]

Ats666, see the upper roller?

 

[BadgerMan]

The old 2 bolt oil drains got yet another? I know Suzuki states that both have to be pulled. Never knew Yamaha's had this setup also. One of the funniest threads was trying to tell a guy which hole it belongs in. Stupid online micro fiches are priceless. Just the swingarm bearings, man did you find a steal! Nice bikes.

The YZ has just one plug that also serves as the drain. The bike needed a little more than just swingarm bearings. I have replaced the plastic, tires, tubes, bars, clutch lever assembly, grips, cables, and pipe mount. I have gone over the bike completely, changing all the fluids and regreasing everything. I am pretty sure the steering head and swingarm bearings had never been regreased. I am thinking about pulling the trigger for a new DG pipe and muffler as the stock pipe has a small leak and the muffler has no packing left. I just don't want to end up having more into the bike than it is worth. :laugh:

 

[TRexRacing]

Here's the part number on my '80 465 fish for the swingarm protector,431-22151-03-00.And a pic of the fish.It's number 10.A quick google search and it seems to be available.And you need it.

And aren't Yamaha's prices getting just a bit outta hand?Went to order pistons for my RZ350 and the dealer said $150 each.I looked at him and said "you're making it hard to support the local dealer 3 months ago they were $54 each.And I can still get a pair online for $160 shipped."He shrugged his shoulders and I'm buying them from someone else.

 

[2strokerfun]

I just don't want to end up having more into the bike than it is worth. :laugh:

Everyone has more money in their vintage bike than it is worth. Part of the fun is tinkering with them. Everytime I tinker, it costs me at least $40.

 

[whenfoxforks-ruled]

Sheeeeet! No fox rear shock man? I know a guy with a bunch of forxs also, 1500 hundred bucks a pop! Boy would it feel plush! When I pulled my 370 engine down, I was surprised to see it really was the first time. Kinda like when I found my wife? But, the appearance from the outside, a double bagger for sure, the bike I mean! Most aluminum swingarms I have been looking at, they require massive welding, the chain slider and shock mounts? Decent frame? And wtf happened to them sweet magnesium covers? Did guys put acid in the trannys? You have a really impressive find there!

 

[whenfoxforks-ruled]

Mail orders, try Service Honda, they do cover ALL jap bikes now.

 

[TRexRacing]

Service Honda wants $141 each for the Yamaha pistons.W/O shipping.

 

[BadgerMan]

Anyone have suggestions for gaskets or gasket kits....other than OEM?

 

[TRexRacing]

Nah it's not worth it.

 

[ats666]

Thanks for the picture!

2 years ago I scored big on ebay for my 79yz.
Cyl head (combustion chamber reshaped because he raced)
New head gasket
Fresh cyl on its second over bore with a new matching piston, rings, circlips for a whopping $150!!!


Ebay has some great stuff sometimes if you can be patient.

 

[whenfoxforks-ruled]

Top end kits from wiseco for sure. Flea bay has all the sizes, cheap. Mods or repairs, It goes to Eric, and he has good prices on whats available, Wiseco, Hotrod, and they usually come with gaskets, or optional. I think he is still taking entire motors.

 

[TRexRacing]

I do my best to find OEM engine parts.Sure it can be expensive but I'm only 2nd over on a 29 year old MX bike.And I do ride it.

 

[wfoyz250]

cool bike for sure. I have one myself that I race post-vintage EVO series. The bike is fast and a handful to keep on the ground. I was lucky to find mine as it was an original, standard bore, low-use bike. I have done some suspension upgrades with fork springs and emulators. I also scored a FOX air shock for the rear.

 

[BadgerMan]

Very nice! I’ll bet the suspension mods were a big improvement.

I don’t know how much further I am going to go with mine. It is all stock right now. I have corrected all the bugs and it runs pretty good for a thirty year old bike. If I keep it, I need to replace or rebuild the shock….it damps OK but it has never had an oil change that I can tell. I also need to find some taller period-correct bars for it and am contemplating a new DG pipe and silencer to quiet it down a bit. I plan to strip it down soon and paint the frame and engine.

 

[wfoyz250]

where did you get the green background and number? I like the retro look.

 

[TRexRacing]

Retro look?Dood it's 30 years old.

 

[BadgerMan]

where did you get the green background and number? I like the retro look.

The plastics came from DC Plastics as well as the backgrounds which they made for me out of some thicker more durable material. The numbers and lightning bolts were custom made by copying the numbers (font) on photos of Bob Hannah’s 1979 OW40 works bike. Yeah, I think it turned out really nice. Now I just need to spit shine the rest of the bike, LOL!

Where did you get your rear brake arm?

 

[wfoyz250]

brake arm?....ah you noticed that huh.
would you believe it's a high dollar, machined from billet......blah, blah,blah......
Seriously, it's from a early/mid '80's CR 125 or 250.

 

[BadgerMan]

brake arm?....ah you noticed that huh.
would you believe it's a high dollar, machined from billet......blah, blah,blah......
Seriously, it's from a early/mid '80's CR 125 or 250.

I might have to seek out one of those high dollar items :nod:

 

[TRexRacing]

Yeah they're available in billet but stupid expensive.So now the cost of early '80s CR brake arms just went up. :yikes: