XTC 600 Help

9

97vmaxxtc

New member
Joined
Dec 20, 2004
Messages
51
Location
Sebewaing, MI
Motor is basically stock, has .8mm head gasket, and an exhaust can.
Problem is when I let off the throttle and get back on it, it bogs for a few seconds before RPMs shoot up and it pulls. I've turned what I believe to be the fuel screws out to 2 turns. Clutching is the same as when I got it, fairly sure it is stock. I would guess that it is a clutching problem but I am far from an expert in this situation. Right now, if I pin the throttle from an idle, it will engage 2500-3000 rpms, will bog and then spin up and pull pretty good. If I tickle the throttle, I can get it up to around 4000 rpm engagement. Now, last year I put a new belt on and the thing ran awesome, engaged around 4 or higher (i put in a couple engagement shims) had great power down low and ran great, i can't remember if it bogged or not getting back into the throttle after letting off. BUT, a couple rides later, the sides of the belt were shiny and it was back to the low engagement and bog off the start. Whats my problem here? Clutches are aligned properly. The belt sits flush or maybe a few thousandths high in the secondary. This bog is killing me, along with not having any power off the line.
 
Well,

Had the carb cleaned this year? I would start there. Next is the primary. Has the spring ever been replaced? How about the rollers? Are there grooves on the fly weights sliding surface?

If your shining up belts after a few runs there is something wrong. Next time your out see how hot the clutches are. Should be warm but not hot.
 
FuzzButt said:
Well,

Had the carb cleaned this year? I would start there. Next is the primary. Has the spring ever been replaced? How about the rollers? Are there grooves on the fly weights sliding surface?

If your shining up belts after a few runs there is something wrong. Next time your out see how hot the clutches are. Should be warm but not hot.
Click to expand...
Thanks, I cleaned the carbs at the start of the season. I had to replace one roller because the bushing was shot. I replaced the primary spring with the stiffest I could get from Yamaha (I believe). The weights look like they are in good shape. One thing I should check is the jetting, a buddy mentioned that it may be running too rich, I will look into that when I can and check the plugs. I think jetting is stock, I could probably go down a size or two.
 
97vmaxxtc said:
I think jetting is stock, I could probably go down a size or two.
Click to expand...

Be very careful tho if you do...keep an eye on thos plugs..cardboard brown
is what your after.
 
daman said:
Be very careful tho if you do...keep an eye on thos plugs..cardboard brown
is what your after.
Click to expand...
Yeah, I will make sure of that. Does anyone know the stock jet sizes for this sled?

BTW, Daman - I'm from Sebewaing....You're not too far away.
 
97vmaxxtc said:
BTW, Daman - I'm from Sebewaing....You're not too far away.
Click to expand...

Really!!!.....cool. ;)! . you live in town??
we get up there when there's good snow...have to meet up some time.

Welcome man!!
 
daman said:
Really!!!.....cool. ;)! . you live in town??
we get up there when there's good snow...have to meet up some time.

Welcome man!!
Click to expand...
Yeah, definitely - I live a mile or so out of town, I'm hoping we get a little bit of snow or at least it stays cold for the weekend...Went riding out on the bay last weekend of of Sebewaing - riding was good, but the ice wasn't all that thick. 3-4 inches most places. The cattails were good jumping though ;)!
alittletwist.jpg


Also, I've been reading up a little bit and am a little unsure about deciding between jetting down or moving the needle down slightly (that is if it's running rich). Would moving the needle help primarily in the midrange? And the main jet primarily at WOT? The bog is basically low and midrange, not so much at higher RPMs.
 
97vmaxxtc said:
Also, I've been reading up a little bit and am a little unsure about deciding between jetting down or moving the needle down slightly (that is if it's running rich). Would moving the needle help primarily in the midrange? And the main jet primarily at WOT? The bog is basically low and midrange, not so much at higher RPMs.
Click to expand...

Nice air man!!!......LOL:)

first off are you shure it's not a clutching problem,,when does it engage??
 
daman said:
Nice air man!!!......LOL:)

first off are you shure it's not a clutching problem,,when does it engage??
Click to expand...
I'm not sure what the problem is, but clutching is definitely on top of the list. Engagement varies....if I pin it from an idle, it will engage 2500-3000 rpm, then it bogs a bit before rpms come up and then its fine, but sometimes when i slow down to just above engagement it seems like it is in too high of a "gear" yet. Saying this convinces me that clutching is a problem, but I need some input from others. If I tickle the throttle I can get it to engage around 4000 rpm, but the bog is still there at first.
 
OK..did you ever do a compression test on it,,

my xtc Engages at 3000 but i have no bog,,also when it's warm it makes
a sled somwhat boggy too i've noticed,,not saying thats the problem tho.

Is your carbs all at stock settings????
 
If you cleaned the carbs and you know they are good then there is a clutching issue. How and when it engages is a place to start. Should be ~4000 RPM with a gentle engagement.

You mentioned you put the stiffest spring you could find in the primary. It should be the White Silver White short spring if it is stock. Any other spring will have the wrong preload, spring rate and total force. The WSW spring is one of the stiffest (short spring at 35kg preload, 2.25 rate 110 kg total force) especially at preload. If yours is not stiff enough the weights will fly out too soon and the 600 does not have enough torque to overcome the early engagement.

Do you know what weights are in there? Should be 8cr's with 13.9g inner and 17.2g outer rivets. Also is the roller you changed the large 15.6mm roller? There are 15mm and 14.5mm and 14mm rollers available. The XTC uses the 15.6 which basically acts like a fulcrum for the weights to pivot on.

Have you read the "How Clutching works" on the tech page by Yamarider? You can see a cause and effect of every change.
 
FuzzButt said:
If you cleaned the carbs and you know they are good then there is a clutching issue. How and when it engages is a place to start. Should be ~4000 RPM with a gentle engagement.

You mentioned you put the stiffest spring you could find in the primary. It should be the White Silver White short spring if it is stock. Any other spring will have the wrong preload, spring rate and total force. The WSW spring is one of the stiffest (short spring at 35kg preload, 2.25 rate 110 kg total force) especially at preload. If yours is not stiff enough the weights will fly out too soon and the 600 does not have enough torque to overcome the early engagement.

Do you know what weights are in there? Should be 8cr's with 13.9g inner and 17.2g outer rivets. Also is the roller you changed the large 15.6mm roller? There are 15mm and 14.5mm and 14mm rollers available. The XTC uses the 15.6 which basically acts like a fulcrum for the weights to pivot on.

Have you read the "How Clutching works" on the tech page by Yamarider? You can see a cause and effect of every change.
Click to expand...
I *believe* it is the W-S-W spring, I am not sure because I'm not with the sled at the moment. I do remember, however, when I was buying it I got the one with the most preload. I am not sure on what weights are in there, and I got the correct bushing, it was for the XTC 600 and I also matched it up against the other bushings in the primary. How often do bushings go bad in the sheaves of the clutch (the cover and the moving sheave bushings)? With the belt off, I can rev it up a bit and the primary will not move until I reach 2-3k rpm and then it will "snap" in rapidly. When it does this with the belt on it will jerk the sled slightly, but doesn't have enough force to move the sled without more throttle. What could be causing this binding? I took all the weights and rollers out and cleaned them, and lubricated everything else. I did not, however, split the primary.
 
97vmaxxtc said:
I *believe* it is the W-S-W spring, I am not sure because I'm not with the sled at the moment. I do remember, however, when I was buying it I got the one with the most preload. I am not sure on what weights are in there, and I got the correct bushing, it was for the XTC 600 and I also matched it up against the other bushings in the primary. How often do bushings go bad in the sheaves of the clutch (the cover and the moving sheave bushings)? With the belt off, I can rev it up a bit and the primary will not move until I reach 2-3k rpm and then it will "snap" in rapidly. When it does this with the belt on it will jerk the sled slightly, but doesn't have enough force to move the sled without more throttle. What could be causing this binding? I took all the weights and rollers out and cleaned them, and lubricated everything else. I did not, however, split the primary.
Click to expand...

Yea it should not "snap in" like that you may have somthing binding,,like FB
said should be a smoth engagment,,

need to take the clutch off and give it a good going over again,,mabie you
missed somthing.
 
daman said:
Yea it should not "snap in" like that you may have somthing binding,,like FB
said should be a smoth engagment,,

need to take the clutch off and give it a good going over again,,mabie you
missed somthing.
Click to expand...
Yeah, I probably didn't do it thorough enough and thats what is causing all of this. I didn't take the clutch out of the machine when I inspected the weights and rollers. It it hard to pull off?
 
No not hard too to do..you just need to get your self a puller,,remove
the long bolt that goes through the clutch to the crank, thread the puller
in and hold the primary good so it don't turn and then put a air impack
on the puller give it a few shots and it should pop right off.

I think a puller is like 20-30 bucks,,everyone should own one.
 
daman said:
No not hard too to do..you just need to get your self a puller,,remove
the long bolt that goes through the clutch to the crank, thread the puller
in and hold the primary good so it don't turn and then put a air impack
on the puller give it a few shots and it should pop right off.

I think a puller is like 20-30 bucks,,everyone should own one.
Click to expand...
Yeah, right now I'm pretty convinced that it is a clutching problem. I would imagine that is what I overlooked and what needs service. Thanks for your help!
 
97vmaxxtc said:
Yeah, right now I'm pretty convinced that it is a clutching problem. I would imagine that is what I overlooked and what needs service. Thanks for your help!
Click to expand...

Well it's a good place to start anyway..then you can go from there.
keep us updated Dave,,good luck man
 
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