XT600 49L restoration

[FarmXT]

Hello all,
Well done on creating a really interesting forum!
I have recently joined to gather information and help to restore my 1984 XT600.
I have big problems. The bike was acquired with plenty of bits missing and with a cracked barrel casting. Apparently when revved really hard they will do this. Is this so? A new barrel was supplied so I have put it together to find out what else is bad.

To my surprise the gearbox has a big problem where it throws out of every gear except first. As you accelerate it will violently throw down a gear. The gears can be "held" by keeping pressure on the shifter but there is a fair force wanting to throw it out. It is unrideable as it was (insert appropriate emoticon here).
I removed the clutch cover to inspect selector star wheel, detent, spring etc and this is fine.
I have split the cases to reveal bad pitting on 3,4,5 gears and their respective idlers. The shift drum is not too bad with one "peak" of one track maybe 0.5 - 1mm worn. The forks look like new, the dogs on the gears look like new, the teeth while badly pitted are even across the face of each tooth (if that makes sense) i.e. they show no edge damage or angled wear that would want to force them out of engagement.

So the questions:
Has anyone experienced this before? I never have in 40 years of bike ownership had anything like this. Searches do not bear much specific info.
Where is a good place to source gears? S/H is fine for this project.
I have located a gearbox from a 2WK 1988. Will these gears be compatable with my 49L 1984?
Has anyone used the Moorspeed gears and what is the story with these? i.e. does anyone know where they are sourced?

Thanks for any help or info offered1
Regards
FarmXT

[Mezo]

Well a good source is the USA for a complete gear set at a reasonable price, Eric has sourced three gear sets (read his rebuild posts) for as little as $50 +postage.

Make sure you ask the seller if there is any pitting on the gears, ask for pictures.

Mezo.

[FarmXT]

Any thoughts on what might cause the jumping out of all gears?
Also i cant find dimensions for the shift fork fingers. Can anybody help?

Cheers,
FarmXT

[Mezo]

The dohickey that holds the selector drum in gear can wear or break (pics on here somewhere) but this isn’t as common as worn selector dogs on the gears.

No measurements to be had in the workshop manual.

Wait a few days & a few of the guys will chime in, weekends is quite on all forums.

Mezo.

[FarmXT]

Thanks Mezo,
The "dohicky" is the first thing I checked. It is good, the spring tension operating the dohicky is good.

I have measured the selector forks and they are 4.72 - 4.82mm thick. The right one is a bit worn & is the 4.72mm thickness. The others - you cant tell that they have rubbed anything, they look new.
I have measured the idler & countershafts for run out & they measure up perfectly!
The input shaft bearings are maybe a bit questionable & I will change them but they would be reuseable.

This one has got me beat so far....
I am keen to hear all your ideas/suggestions.

Cheers,
FarmXT

[steveloomis]

Sounds like the forks could be bent and lot engaging the gears properly. Can you tell if the crankcase has been apart before? If so, maybe incorrect parts installed.

[FarmXT]

Thanks for replies.

I can see no tell tale signs that it has ever been apart before so I think it is original.
The forks do not 'appear' bent but that is pretty hard to gauge without another to compare. The wear on the forks is from non existant to slight (measures 0.1mm under). The dogs on the gears have marks on them as I would expect but in no way are they chamfered or damaged. The shaft bearings are a bit worn - could probably use them again but I will replace them as a precaution. The shafts are true - I cannot measure any runout.

My conclusion is becoming that the worn gear teeth must be high clearance and the chatter that this allows must be throwing the gears out of engagement.
I have a gear set on the way (from a later fine splined chain sprocket model) and I will attempt to make these work.

Ill keep you posted.

Incidentally, I emailed the site who sells uprated gear sets but they have not bothered to reply... Not too keen for new business it seems.

Enjoy your XTs over the break.

Cheers,

Farmxt

[xtrider]

The new style trans (XT600E models)won't fit the older XT's, you'll need the original years. I have 3 or 4 sets from the '84 thru '89's(and 2 complete &running motors) need something just ask. The coming out of gears would most likely come from something not "locking" in fully when it is shifted. Either the star or drum is off and not fully pushing the gears in. So the engagement dogs on the gears themselves are nice and square with no rounding? how about the slots in the corresponding gear? If a fork is bent you'll have one side of the wearpad ground down plus it'll often rattle like hell when running due to the fork holding a gear in the wrong area and rubbing on one gear or another.

How much did you get the new transmission for ? I might take it off your hands as a spare in case I need it for the 3TB('90-'95 us models) I just found for next to nothing (my second one).



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[FarmXT]

Hi,
Thanks for the info. When did the gears change? I ask because the 'new' gears I have appear the same width as the 'old' ones. The only difference I can see (without fitting them to the counter shaft) is the counter shaft on the new set is for a fine tooth sprocket.
I guessed that if they will not fit my original counter shaft I would have to get a sprocket to fit the new shaft. Am I being too optimistic?

More questions; the left end of the balance shaft is just starting to show signs of wear/damage. Am I unwise to reinstall this or can I get away with it?
The gear selector shaft quadrant teeth are spread a bit and one is cracked. Can I weld & regrind this or is it a throw away?


Thanks,

FarmXT

[xtrider]

The problem with fixing those shifter teeth is if it doesn't hold, you have to split the cases. The gears were changed in 1990 here in the states. If you have a fine tooth on the counter shaft it won't fit the kick start XT's , only the e-starts had the finer splines. They didn't make an inbetween setup, either course splines for the '84-'89 and fine for '90-'95, If you line the 2 shafts up you'll see the finer spline is .312" (8mm) approx wider. Each gear is about 1/16" wider. Unless there is some shaft that I've not heard of before. The clutch shaft(input) has a finer spline, you didn't get that one did you?

Wait and see what the trans turns out to be, if you end up needing a different set I have one plus that shifter pawl I can throw in, even a drum .



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