I'm the third owner of a '83 Maxim and it recently stopped working for me.

I was driving to work tuesday morning, and about 3/4 through my trip, while I was pulling out on to a main road from a stop sign, all of a sudden I couldn't shift up. I was reving up in first, I tried to shift to second, and I couldn't. It feels as though the shifter arm gets stuck just before reaching the point where it changes gears. Applying force does nothing. It's locked in first, and I can't even get it into neutral.

My first thought was there is some blocking the transmission, and I'm still not entirely sure. I'm waiting until this weekend before I begin opening up the engine for a real diagnosis. But I did open up the gear selector box, in the hope it might be something closer to the outside of the engine like a bent selector fork or something... that wasn't it.

Any advice anyone has to offer me about this would be greatly appreciated. I'm a mechanical trogladite, but I have the haynes manual, and I'm pretty good with following instruction for LEGO and Ikea furniture.

I had the same thing happen on my seca, when pulling away from a stop light it went into first but then wouldn't up shift. I got lucky and it was just that the adjuster that raises the level of the shift lever loosened up so the lever would hit the engine case when I tried to shift. I just re-adjusted it and made sure the locknut was tight and went on my way. I hope yours is that simple. If not then it sounds like a bent shift fork shaft to me (cheap part but in the center of the transmission). Does the shifter feel any different up until it gets stuck?

I found the problem.

I've taken the engine out of the frame and dismatled it. When I first opened up the oil cooling pan (belly pan) I found pebble sized chunks of black plastic everywhere. It was one of these piece that was blocking the shifter from shifting.

I continued to dissasemble the engine, split the crankcase case, more black pieces everywhere.

It turns out the primary chain guide exploded, and that is where all the black plastic was coming from. And the primary chain guide is one of the most inaccesable parts on the whole bike.

That's where I'm at now, I've ordered the parts, and hope to start reassembly in a week or two.


Has anyone else had this problem? It seems odd that yamaha would decide to put in a hard plastic chain guide in the core of the engine, it's the weakest piece in there. I can't be the only one who's had the thing eventually shatter.

Plastic?!? Bummer! I can not even imagine why or who thought that one up. I just hope plastic is not a factory standard. Is the new part you ordered plastic?
Best of luck. B)

It is what it is.

Plastic guide in the front and back on the tensioner.

Not to mention the plastic coated metal from for between the cams.