I have a quick question about any experts out there on the moto 4. I have an older (1986 about) moto 4 i just picked up and the rear end is out. The whole back end is out and a mechanic said that it needs to be replaced or have the right part fixed. He said that buying an used whole rear end might be less expensive then buying the part needed. My question is: can anyother moto 4 (different size) rear end work on my 80cc moto 4? (I have seen 200cc moto 4 rear ends for sale, would that work?). Also, if anyone needs to get rid of any 80cc parts, email me or if anyone knows of a good parts site.

Thanks
Swift

 

Problems with the rear ends were common on these machines and still happen on the newest 80's if they are not maintained. Usually it's the ring and pinion gear that go out. The problem there is that the ring gear is made to the axle on that model. When the gear goes bad, you have to replace the axle.
To replace the ring and pinion gear along with the bearings and seals, you will be looking at about $600.00 to fix. Yamaha doesn't sell the rearend as a assembly.

The only othewr model that has a rearend similar to the 80 is the Yamaha Champ 100 that was discontinued a few years back. It has the same parts as the 80. None of the other Moto-4 models have parts that will interchange.

 

Hey Knowsalot, is that true of the Raptor 80 and Badger rear end as well?
That's all the same rear end isn't it? I saw two Moto 4 junkers on E-bay, one had the rear end out of it.

 

From what I was told, any of the rears that have a dipstick, have the newer supposibly better rear gear setup. The older ones that don't have a dipstick are the ones to stay away from. As far as any other rears exchanging with yours, I really don't know, but it looks like they bolt up the same.

 

I can't remeber where the year model break is, but I do remember that the ones with the 4 bolt pattern to the drive shaft tube are far more reliable than the 3 bolt type. The 4 bolt type were the only ones that had the dipstick. I've seen a few of these go out but no where near as many as the older 3 bolt type.

The newer version will not interchange with the old one. Everything from the engine back is different. Including the swingarm and axle. [The axle is still one piece with the ring gear though]

I have to also make a correction into something I said in my above post. While checking into this, I found that the 100 Champ also uses the 4 bolt rearend instead of the older 3 bolt type. Sorry about that. Everything used in the rear of the 100 Champ has the exact same componets as the Badger 80 and Raptor 80. Every part number is the same across the board.

So that leaves nothing that will interchange with your 80 except for the Moto-4 80. If the swingarms would interchange, you could use the entire rear end from a newer model, but I can't verify if the change is that easy or not.

 

A good friend of mine has a champ that his family bought new in 86. As far as I know, they didn't make these very much later than this one. The biggest difference in it and my sons badger is the champ does not have rear suspension. Their champ does not have the better rear end in it, and they have had to replace it twice so far. Our badger is a 94, and from what I have been told and seen, it is one of the first years for the improved rear end.

 

Knowsalot, I have a first year Champ 100 ('87 I think, and the rear end is out too) that has the 3 bolt type rear end. The following year model included the rear end change, as well as adding the shock to the suspension. I'm planning on taking an old Honda ATC 70 and mounting the motor and axle housing to it to make a Hondahaha out of it.

 

And that same rear end/swing arm, on the Raptor 80, or Badger for that matter, can be vastly improved by remounting the shock forward. (But you have to replace the bent rear subframe struts with straight ones to get the increased travel.) We're getting 7" of travel in the rear, the swing arm and U-joint are holding up fine, despite easily 50 jumps, some in third gear WOT that we did for the ATV Action Mag photoshoot. That was with my dardevil 13 year old riding it, who regularly jumps his 660 Raptor. Now that the quad is back to being ridden by its' intended rider, age, almost 5, suspension is considerably less "stressed".
.... I'm hoping for a long durable life for this axle/swingarm setup. Getting the daredevil back on his own ride was the first step. [img]i/expressions/face-icon-small-cool.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-smile.gif[/img][img]i/expressions/face-icon-small-wink.gif[/img][img]i/expressions/face-icon-small-tongue.gif[/img]

 

can anyone tell me the exact chain tensioner bolt size for the 87 champ

 

You might get a 100 champ rear end to fit it, any model above that won't be anywhere near interchangeable.