2nd gear exploded (well came apart anyway)...

[CorruptedFile]

Hey guys,

I have a '92 750 Kat. While I was out riding it yesterday, I was taking off from a stop sign under pretty good power (making a left into flowing traffic on a rural road), when I hit 2nd gear the was a loud pop then some chunky noises and it felt like the gearbox was either slipping or fighting itself. Shifted up to 3rd and everything felt good again aside from the something clunking around in the gearbox. So, I believe that 2nd gear has come apart on me. Am I on the right page in thinking this?

Local service department told me that 2nd and 6th are on the same shaft and that if 6th was gone too then it could be the slider that came apart, but I didn't want to get the bike up to that kind of speed to test out 6th.

How hard is it going to be for me to find parts and the like? Is it worth rebuilding the gearbox, or should I just replace the whole engine? I would rather not have to do that because the engine runs great.

Thanks for any advice you can give me.

[arsenic]

The parts are easy to find, but unless you do the job yourself, it's 25 hours labor minimum. It's not an easy job either. If I were you, I'd start searching for an engine.

[CorruptedFile]

Yeah, the service guy said that if they did it it would be a minimum of 14 hours just in the teardown and reassembly. Which made it a definite DIY project. For the parts themselves, what should I be looking for New, Used, or just buy a trashed engine for the gears?

Just thought of another question in addition to this one.

What years of engine/transmission will work in this bike? Am I looking at parts for Pre Kats only or will any Kat year work?

Thanks.

[Kreylyn]

PM Talltec, he's just done a trans rebuild and can probably give you some pointers.

Trans parts are specifc to cc and certain years. Use the parts fiche at websites like www.ronayers.com to confirm the parts you need, and the year range (the letter codes corresponde to the years used... )

Krey

[boomer_95]

if you are going to rebuild, make sure you GO SLOW and find every shim/thrust washer and where they go.. one misplaced shim and the trans will lock up and be utterly useless, as you will have to tear it down again. once everything is in, put the trans cases together and go threw the gears a bunch of times while spinning the input shaft (or output, whichever is easiest). so shift into a gear, and spin the shaft a bunch of times, then shift to another gear and repeat. once every gear is good start rebuilding the rest of the engine. if one or more gears lock up while spinning the shaft you have to tear it back down and figure out what shim you misplaced

its a very slow and tedious process so don't rush and take pictures if you can. specially if you will be waiting for any length of time. also take notes as well and have some sort of organization process between left, right, top bottom cases/parts. that will save you some time trying to figure out were things go.

[CorruptedFile]

Thanks for the advice guys. I've worked on cars and even rebuilt some engines before, but this is the first time that I will have tackled a motorcycle engine and trans. So all the tips are greatly appreciated.

[Talltec]

give me a few hours i will give a small step by step to getting to the gears

its not that hard and if all goes well you will be in out in a day if you have everything u need to replace the broken parts it took us two weeks because we cracked open and had to wait for parts

also i got real lucky since other then for a few scratches on the shifting forks i wasnt sure what was damaged and a fellow kr member sent me a complete tranny both gear racks and shifter and forks for it so all i had to swap mine out with his

[Talltec]

here the basic parts
Just remember to document any bolt you remove with measurement and location

Drain oil and remove the small sprocket
1. Remove Engine
2. Remove Alternator
3. Remove all three Side covers ( what I did also is I took a notepad and drew each cover on it with respective holes and as I took each screw out I measure it and make it on the drawing also got some cheap ziplock bags and maked it with what cover or what stage it is and placed all the part together on my table.
4. So at this point it should just be the motor (no oil cooler,carbs)
5. Major thing is don’t force it and also make sure you have all the right tools if you have a impact that works the best for the next step
6. take the 6 six clutch bolts with springs off then after that you take the big nut off with impact once you did that genteelly take the clutch basket out while u do that take picture of each step makes it easy to put it back together.
7. one you did that on the left site is a small plate that cover the shift rod oil seal and also sprocket gear remove it
8. once you have remove the clutch and main gear you should be able to see where the lower and upper gear case come together
9. once you see where it comes together remove all the upper bolts and nuts from the gear case also on the clutch side remove any part that may hold the top and bottom together.
10. once all the nuts bolt and brackets have been removed. You will need to remove the oil pan the oil tubs oil funnel and any bolts or nuts holding the lower to the upper . if you don all that correctly you can take a mallet and smack the lower all the way around the joint and it should come lose quiet easy if it doesn’t you may still have some bolts or nuts holding it together. On of the reasons you remove the alternator is because there is a nut and a bolt that you can only access thru that location.

feel free to contact me any time thru email or if you are a paid member i'm in the chat most evenings and weekends

it kind of crude but if you are mechanically inclined this will be quiet easy. i have a few tricks on how to get it back together which is super easy also if you going to do this replace all three seals on the left side the shift rod the sprocket and and the shifter oil seal

Depending on time frame you looking to do this i might have a good Tranny for sale but not sure it will since this is coming out 600 and not sure it will work on your 750. i have a complete motor with a good tranny but will not offer it till i know the other motor i have has a good tranny

[CorruptedFile]

Awesome Talltec, this is great. Thank you very much. I've got a line on an engine with a bad top-end but a good tranny. If that doesn't work out then I saw quite a few gear sets on eBay. I'm not in too much of a hurry either as it is getting into winter I don't expect to be riding again till spring. I noticed in the service manual that there are quite a few specific tools listed, are these really necessary or are there some alternatives? For example the tool to hold the clutch from moving while trying to loosen the nuts?

[scottynoface]

For example the tool to hold the clutch from moving while trying to loosen the nuts?

You can make your own with a steel bar, a drill press, and some nuts and bolts. Suzuki wanted $90 for their special spanner wrench.

[CorruptedFile]

Cool, that's what I was hoping.

Thanks.

[boomer_95]

a good impact gun works too

[scottynoface]

T

a good impact gun works too

Oh yeah, i was thinking of the ignition rotor holder

Impact ftw on the clutch nut.

[boomer_95]

T

Oh yeah, i was thinking of the ignition rotor holder

Impact ftw on the clutch nut.

you can make a clutch holder like the way you said (cept you need 2 bars). i just like impact guns

the haynes manual shows a way to make the holder tool if you want to go that route.. you can download it here from the wiki

[CorruptedFile]

Well, thankfully I have an impact!