Please Help!

I just purchased a 2000 426, it is all stock except for a bills header and muffler. I was riding down my street and I noticed that occasionally when I get on the gas in one of the tall gears it feels like the clutch will momentarily slip. It almost feels like I am on the gas and someone has squeezed the clutch for a mili-second. What do you think is causing this? Do you think I should replace the clutches? Is there something I have to adjust? Could it have something to do with my oil being dirty? I don't think it is in the transmission because it doesn't always happen and it doesn't make any clunking noise, plus I have had gear boxes go out in shifter karts and this is different. Thanks for any advice!

This sounds like a worn gear pair/bent fork in the transmission. If it only does this in one gear, usually third, fourth, or fifth, and acts as you describe, that's probably what it is. Sometimes you can get it to skiip out on you on a stand in the suspect gear by yanking the wheel backwards.

That sounds expsensive!!! Do you think I should just ride it until the gear goes out all together? My thought is it probably won't even happen in the dirt because the traction is not as good in the dirt as it was on the street. I had a shifter cart with a bent shift fork and it would just pop out of gear, like I said this just slips for a second and it's intermitten.

Now lets assume that it goes out all together, do you recommend any good shops in so cal. I did the transmission in my kart but I have never tackled a four stroke. I assume the transmission is similar so I may just do it myself. Thanks for the advice.

If you do a search in this forum, you Will find a few threads to give you great info on this.

Two things

As was said above, most likely a bent shift fork, but (THE PROVERBIAL BUT)

It is most likely the 3rd gear fork that helps control the meshing of 4th and 5th.

Only thing to do is break the cases and take a look, You can ride it all you want, but (Again The Proverbial But) AT WHAT COST

You are looking at a few hundred dollars to fix it now, Compared to 1k if you explode the tranny

Your choice

I tried to do a search on this topic and I could not find anything, it's probably because I am new and was doing something wrong. As far as the cost, I'm sure it will be more than a couple hundred bucks if I have to pay someone to plit the case. If you know someone who will do it for a couple hundred bucks I'll take it to them next week. However I would like to do some more research before I split the cases myslef.

Next question, lets assume I kept riding it, if it is a bent fork then eventually it will get worst and it won't stay in the fourth or fifth gear at all, however I wouldn't think it would do anymore damage to the trans (except for maybe round off those gears which I would replace anyways when I split the cases). I'm not saying that I am going to ride it until blows, just trying to get a better understanding of what is wrong with it, and what will happen if it gets worst. I do have a trip planned to Cal City over Thanksgiving and I would like to be able to ride a little.

Once again thanks for all the help, as you can imagine I'm slightly bummed becasue I just bought this bike and it is very clean and looked well taken care of.

First off I never said a couple hundred bucks I said specifically

You are looking at a few hundred dollars to fix it now, Compared to 1k if you explode the tranny

And I will stand by that Less then $500 Most likely around $400

To do a search

Here follow this link

Search on Gear Skipping

Riding the bike is your choice, with choices comes consequences.

Its your choice, your bike :cry:

I wasn't quoting really your price, just making a point, in fact I didn't even know you were speaking specifically about doing the work yourself. If that is something you do, let me know where you work and how I can get a hold of you.

As far as your comment about "choices having consequences" I am aware of that. Like I said, I have had shifter karts with trans problems, specifically bent shift forks and the trans would pop out of gear all together, it wouldn't go in and out like it is right now. When I ran my kart with the bent shift fork it didn't cause any other damage, however I did replace a couple gears anyway. Basically I am trying to get informed before I split the cases or pay someone to do so, not saying your right or wrong. Thanks for the advice and the link, I will look that over.

With many transmissions, it would just pop out and stay out, but the way the YZs cut their shift cams, it's a lot harder for that to happen, and typically what you describe is exactly how they behave in the early stages of this problem. You have to remember, too, that the transmission lives in the engine's oil supply, and everything that comes off of your trans will want to get pumped past the pickup screen and up into your oil tank, where it will try to get at the engine itself. So, unless you want to have a really huge problem on your hands, better get after it.

As far as where to take it, ask around the area where you live, but my advice would be to lean towards the best Yamaha dealer you can find, unless an independent is highly recommended. Dealers have access to the latest and most complete information on your bike, and if their service department is well run, will be cheaper in the long run.

Or if they are smart they read TT! :cry:

I think you need to clarify the condition your explaining. When the bike feels like it is "slipping" do the RPMs go up? In other words does the engine race as if you pulled in the clutch with the throttle constant? OR is more of a stumpling or cutting out of the engine?

I have seen engines not jetted properly cut out in high gear pulling a slight load. This makes some rider feel that something is slipping. However if the engine isn't racing (rpms unstable) then your not really slipping.

Test that theory out before you split the cases. My bike did this and I thought "OH S*#@, I am a member of the 3rd, 4th, 5th (or whatever) gear club. I ran it a little more and realized the engine was cutting out or "missing". One good carb cleaning and tweak the jetting and I was running fine again.

Just food for thought.

Is it slipping or skipping, slipping is smooth, skipping is not. If it is truely just slipping you probably just need new clutch plates and springs, a very easy job. Get on the gas hard in first or second gear and see if you get the same slip, if so it's the clutch.

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