Hello again All,

I am in the process of replacing the silient chain in my 03' 250 trailblazer, and i noticed that the output shaft sprocket has a fair amount of play, but the output shaft gear is solid. All of the teeth look fine, no chips, etc. There also wasn't very much for metal shavings on the plug magnet. I am curious what the tolerances my be on the sprocket to shaft connection. Other than that, i am trying out the 38T sprocket on the rear final drive, replacing the engine mount, rebuliding the clutches with new clutch kit and trying to make it shine. (thats kinda hard here in GA) Was thinking about adding a pipe, but i used to do that with my sleds and i really don't want to be changing jets and such, just to go riding. That is more of a race day thing as far as i am concerned. Any advice or info is greatly appreciated. I already tried searching many forums to find somethin on this an found nothing. Well, Thank you in advance and have a great day

Justin.

 

There will be a little play in the output shaft sprocket on the shaft as it wears over a period of time. Like you said the shaft is a lot harder than the sprocket itself. I've seen a lot like this and shouldn't cause any great concern.Even a new one will have a little back and forth play.The main thing is the condition of the outer teeth.PLUS if your talking about the sprocket the silent chain goes on,then yes it's normal for it to have play also and I've never had to replace one of these big gears! And I never really noticed that much shavings on the drain plug magnet when I just replaced the chain,just a fine film of metal.Have seen some though that were a mess when they used the wrong oil or neglected them! A jump up from the 36 to a 38 tooth sprocket should be noticeable on take off in addition to what else you're doing clutch wise. The guys that are into performance goodies should be along to give you any suggestions they have. I just tried to keep em running. OPT

 

Thanks for your input OPT. I've read an infinte amount of your posts, and you always have awsome answers and explinations. The outer output gear has zero play, but the inner has float and wobble, so being that i never took one these types of gear cases apart i thought it might be a concern. Another question I have is about the shift fork pin. Is that supposed to have play as well? it moves about an 1/8 of and inch to maybe 5/32". I like to keep em up an running too, but i don't ride any fields and such (mostly tight trails, mud, and hils), but being an old seld cross country racer (when they used to exist in upstate NY}, and an avid trail rider i thouroghly enjoy a light machine with good torque. It's my first bike so i figure its an easy one to learn my way around. I would eventaully like to find a race circut and get my kids into, like my father did for me.

 

Another question is about a bog. I live on a gas line, and when riding wide open over levies, when i come down it bogs until I let off the the throttle. Once i let off i and hit it again, it takes off until i get air again and and come down again? Could it possibly be the feul pick up? If so what else could it be (It even happens when the tank is full). I thought it might have been the silent (hence why i am chaging it), but by looking at all the part i don't think it could be

 

Almost all the tranny parts will have a little play in them! Shift forks too! The main thing on shift forks is where they contact the gears to see if they are worn very much or rough feeling from heat. If ok just reuse them. Silent chain slack,worn/ground down shift dogs on the slider gear,main and reverse gear and sometimes bearing wear are the most common things to check for. Since you're in the tranny replace the chain anyway!! It's not that expensive. As far as the bogging,it could just be dumping fuel into the cylinder(needle and seat/float arm problem) and takes a little time to "recover", plus check that the carb vent hose is away from the exhaust and open.If you still have the "T" that the vent line and fuel bowl drain share,I'd get rid of it and have separate lines to make sure the carb vents properly.Plus being a piston port engine and not a reed valve engine,a little bogging/hesitation is usually normal. OPT

 

i am planning on checking the float level. How do i get rid of the 1 way valve on the vent? I am going to have to look at a diagram of the carb. there is 1 line that has the 1 way vent, and another line that just hangs. The line that hangs looks like its be torn off? are there supposed to be 2 open hoses on the carb? I didn't think there was supposed to be. I also just purchased a replacement A Arm for the left side last night and i was curious of the left and right. I noticed that they have 2 different part numbers, but it looks like they are interchangeable. (Unless the length is different). I think i am good with the clutching theory now. Drive clutch controls the RPMs, and driven controls up and down shift (Torque, acceleration, top end.) I think I am going to get an Aaen Torquer pipe, so I can increase RPM. (is the silencer also a spark arrestor?) A 5HP gain is pretty big on this machine, Correct? Approximately 19% increase. My only concern is having to change jets. If i am running higher RMS I would have to richen it up some if I'm Not mistaken, but with a 1000 RPM increase i am not sure if adjusting the needle up would be enough or not? Possibly need larger jets. Anyone have some input?

 

Just throw the "T" away as most fall off anyway. Just have a drain line on the carb bowl and have the vent line(s) at the top separate and run under the tank and zip tie to the choke or throttle cable. I did a bunch this way. Left and right side a-arms are different! They are oriented for one side only. On jetting,unless you get a specific kit that narrows down the jetting options,is a matter of experimenting. The old rule of thumb is 20% up from stock jetting for pipes and performance air filters,etc. There is no set jetting as you have to consider altitude,temperature,the engine itself. The main thing is to check the spark plug after a fast run to determine it's condition. If it's a whitish color,it's too lean.Then you would need to increase the main jet. Plus fine tuning the low/middle power band just adjust the slide needle position. Lower the needle clip richens the mid range. It's mainly trial and error and experimenting You're aiming for a medium tan color on the plug. Complete performance kits help narrow this down,but can get expensive. OPT

 

Awsome. Thanks for the advice. It's been so long since i have done any carburation,(since i was a kid racing), i honestly forgot all of that about checking the plug. I know it and just did'nt even think about. I have it all back together (worked on it til midnight last night), i just need to wash the front rims, plug the tire, and put the rear fender on. It is much snapier with the clutch kit. I am waiting for my new tach to come in, but i would say it engages around 2K or so as apposed to 15, Haven't wound it out yet but it is definitely snottier. Old engine mounts were definitely shot. I used to be able to move it by hand about 3/8" to 5/8", with the new mounts i can hardly moved it at all by hand. I did them one at a time so i am hoping my clutch alignment is still good. Just going to keep an eye on the belt wear. Is there a special alignment tool for ATV"s? I have one for the P85, but it is from my old sleds, and it doesn't fit over the cooling blades on the blades on the back. Carburetor float looked level so i am going to find the fitting and line with the weight for the bottom of the bowl and give that a shot. It cleaned up real nice, it took me some time to get the GA clay out of everthing. I'll Post some pics in the garage hopefully today.

 

I had all the alignment tools,but seemed like they were more of a hassle than just eyeballing the belt and clutches as it idled in neutral. If the belt wasn't centered on the front clutch and was riding a little more toward the inside clutch sheath,I just shimmed out the rear clutch to bring the belt more toward the center of the clutch. Just the opposite if the belt was riding on the outer front clutch sheath,I just removed shims. I just kept a bunch of shims on hand at the shop. OPT