Fix your bottom end!

[nelsonccc]

So as many of you know on our last trip to the Paiute in June I somehow lost everything but 4th gear. Luckily it happened at the end of day 2 so no biggie. I have 4th gear but when I shift down it goes into neutral (a false neutral) and that's it. Then if I shift it back up it CLANKS loudly back into 4th. Being cheap like I am I decided to fix it myself, plus I like working on the bikes and figured it couldn't be that hard.

Pulled the engine (PIA) then I made my own case splitter once I determined it wasn't the shift assembly. Once I got it apart I found that one of the dogs on the 4th wheel gear on the drive axle is missing. It looks to have scarred the 4th pinion on the main axle as well. Seems weird that just loosing a tooth would shut the transmission down and that one tooth missing would cause it not to shift out of 4th. There is some scratching on the shift fork but its pretty minor. I found the tooth attached to the magnetic drain plug so I know it wasn't lodged in there affecting the shift fork function.

Here are some pics if you're interested. I hope I'm not missing something. Everything else seems to be in working order as far as I can tell but maybe you guys will see something that I'm missing.

I'm going to order the parts. It's expensive, especially since I'm in there I might as well change the top end, clutch plates, and all the misc screws and bolts that are broken or rusty. I'm watching a couple of trannys on ebay and hopefully I can pick up a complete assembly for $70 instead of the $200 it would be new.

Anyways here are a few pics. I'll post more as I assemble and test. I shot lots of pics and a video so I could remember how the damn thing goes in!


http://www.youtube.com/watch?v=p3QEhC0tMuc

[REDFOX]

I am curious as to what year your bike is and how many hours or miles you put on it with the original transmission ?

[nelsonccc]

it's a 2000. My friend bought it new in '01. He quickly figured it was too much power for him, he rode it intermittently for a year or so then gave up. I bought it from him in '04 after it had been sitting in his garage for more than a year and didn't run anymore. It just needed the carb cleaned up to run. Since then I've put about 100-150 miles a month on it, typically I average 1000+ miles a year.

In 2006 I did the top end and had the bottom end crank and bearings replaced. So it's the original transmission and is just now 10 years later giving me problems. So I'm happy with the performance and durability.

[JP]

Ouch, I know how that feels :eek2:

[REDFOX]

it's a 2000. My friend bought it new in '01. He quickly figured it was too much power for him, he rode it intermittently for a year or so then gave up. I bought it from him in '04 after it had been sitting in his garage for more than a year and didn't run anymore. It just needed the carb cleaned up to run. Since then I've put about 100-150 miles a month on it, typically I average 1000+ miles a year.

In 2006 I did the top end and had the bottom end crank and bearings replaced. So it's the original transmission and is just now 10 years later giving me problems. So I'm happy with the performance and durability.

Good information thanks ! Is your bike still a 250 or have you bored it out ?

[nelsonccc]

Everything engine wise is stock except for aftermarket reeds. So it hasn't been bored out. I can't imagine having more power.

[Reedus]

Looks all to familiar. Shoot me a pm if you have problems, I fix these things for a living

[nelsonccc]

Pretty straight forward right now. I put the shift forks, shift drum and pawls all back together in one half of the case and went through the shifting to make sure it works and that there isn't something I'm missing somewhere.

Ordered the new tranny stuff this morning. Placing another Bike Bandit order today for all the misc bolts (had one break in the clutch basket) and stuff. Hopefully I can get it up and running before next weekend.

Any pointers or things I should keep an eye on? I already made one expensive mistake! I thought I could leave the piston on and not emss with it but with al the cranking and splitting the case it must have knocked pretty hard 'cause the skirt broke off on one side. No biggie, since I was thinking about replacing it while I was in there anyways. The piston is from August of '06, so maybe it was just getting old/brittle anyways.

[Reedus]

Don't ever buy from Bike Bandit. They are super expensive. Try cyclepartswarehouse outta Texas or even Thumpertalk sells oem and they will match anyone plus they are right there in Vegas. Don't forget your circlips on the piston pin. I did once and it was an expensive mistake. No valves to shim or time, so you should be good to go.

[nelsonccc]

More work happened over the weekend. Spent 9 hours saturday. I'm pretty sure I could have done it in half the time but I was super careful to check everything twice. Like I assembled the entire tranny with only one side of the case to check the shifting and function, just to make sure I had it right.

Started by organizing all the new parts.
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Then I had read that it was extremely helpful to polish and completely clean the grooves in the shift drum and fork ends. So I spent an hour or so polishing and cleaning out all the baked on crap in the grooves.
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Looking at the new tranny (bought off ebay for $90 looked brand new), shift drums, and shift forks all assembled in the correct orientation.
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Pulling the cases together. Major PIA to do the liquid gasket. Kept 'stringing' across everything like hot glue. I used a steel block from the shop as a crank puller. Worked marvelously.
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Put in a new spring.
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then here is the shift pawl assembly ready to go in.
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Here is the shift assembly all back together. Ended up doing this like 3 times 'cause the manual has some weird verbage about rotating the pawl.
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Kick starter put back in. The spring was a serious issue. Pretty hard to wind it and get it into the right holes.
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Original clucth basket installed with the new clutch and the new Tusk HD springs.
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Clutch all together.
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Strator and CDI put back together (hope I got the timing right....) Hard to measure .08" from TDC.
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Old and new piston. the old piston I put in on 08/2006. So 5 years of service with riding almost every weekend. Looks good. I'm a true believer in a 40:1 mix! Made sure I put in the circleclips. I'm extra careful here, 'cause last time I did it one of the circleclips sprung out of the piston and hit me in the eye and then vanished. Had to order a new one, so this time I was extra careful.
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All done and ready to go into the frame.
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Spent another 2 hours last night (no football for me) putting it all together in the frame. I was thankful for the wiring diagrams in the manual. It's super specific and tells exactly how to route the cables. I couldnt remember how the radiator blow off, cdi cable, and YVS tube came together. Got the new clutch cable in...feels super nice! I'm going to pick up a new plug today and some coolant, throw them in and then slap on the tank and take her for a test ride tomorrow, then again this saturday to get her broken in for the Paiute on the 23rd!

[accadacca]

Looking good dude!