I will try to check out my situation on the clutch this weekend and post back to you my findings. You mentioned about different types of clutch materials saying stay away from Kevlar type discs when I go with the new anodized basket. Since I dont know what the previous owner put in there can I visually tell a difference between cork based and Kevlar from what he installed? That would be cool If I can still use the ones in there but I will check out the trueness of the plates on a piece of glass or something as flat.
Just for the sake of looking, I did check out some new clutch kits and most are carbon fibered, would this be ok to use? I'm not sure if I'm allowed to post links here but check this one out if you would...just change the hxxp to http in the link

hxxp://www.kdcycle.com/partsdatabase.html?prod_id=254

Thanks again for your time!

 

You can usually tell if the clutch plates are cork based by looking at them. If they look like cork, most likely they are. Kevlar and carbon fiber plates tend to be more uniform in friction material color. After use, the material will be black regardless of type, so pay attention to its composition, not color. Believe it or not, I have always used Vesrah clutch discs, and I have never had any trouble. The ones in the link are for a 250R if you want to get the part number. A lot of people tend to buy the most expensive or most recognizable name brand without researching the product. I forgot this, but Barnett makes a basket for the 250R, too. Theirs is a little different because it has stainless steel inserts on the basket fingers to further reduce notching. I have no idea how much they are, though. Stainless is a very hard material, so they may be more resistant to notching than an anodized basket when used with kevlar/carbon fiber plates. While I'm thinking about it, another reason to stay away from aluminum drive plates is because they will contaminate the tranny oil. Aluminum, especially when being subjected to high friction, will gall and degrade very easily, even with top-notch lubricant. Plus they wear out a lot faster, warp easier, and are more expensive. Unless you are making serious horsepower and don't care about cost or rebuild intervals, use steel drive plates. Since I mentioned lubricant, I know it's a continuously debated topic, but I refuse to use car engine oil in my transmissions. For the amount of use my ATVs get compared to my cars, using a high quality, wet clutch-specific oil is very beneficial. I cite this Maxima article often (PDF), but it is a good read, and it gives specific reasons why to avoid automotive oils for wet clutch use.

 

Interesting article on the use of automotive oils for the gear box. When the owner I bought the trike off of said he has been using 10w-40 in the gearbox I was a little hesitant of that idea, since the 250r is such a high rev motor. This article has me sold on the higher quality oils available, especially now that you have recommended something I've been wondering about.
On the clutch plates you recommended, I may just go ahead and change to those anyway, price is not bad at all so I might as well add in new vesrah springs too.
I do have one other question for you, nothing to do with clutch components but spark plugs...I have heard tooooo many different people recommending different plugs for this and that..what is your recomendation on those if I may ask? What is in the bike now is a NGK BR8ES. I'd like to have a plug for colder days (like under 50 degrees) and a plug for the warmer summer months above 70 degrees.
I'm not sure how my 36mm carb is jetted if that comes into play but whatever you think will work good for me. I do know that I may have to make some changes as the plug in it now seems to foul out if you sit idleing too long. The use of the choke is a no-no on this bike, really just use it to start a cold engine and then shut it off immediately for prevent fouling. I pulled the plug to check and it seems to be always smelling of gas with a black sooty coating on it, but runs fine when engine finally gets warm, Any help in this field?
Thanks guy!

Mark

 

Yeah, I use the Tech Articles from Maxima a lot. I have met Mr. Lechien (owner), and he is a very intelligent man when it comes to oils. He really knows his stuff! Here is their jetting guide, which I have used to great success. You can read their other articles here. When I was working with the factory Suzuki GNCC teams, we used Maxima products exclusively, so we had a lot of interaction with them. In that time, we never had a single oil-related failure, which consequently includes jetting and spark plug failures. Plus, we netted three GNCC national championships in four years. Your choice of plug is OK, but I suspect your jetting is off, especially if you are fouling plugs. You describe a "black sooty coating." If it's sooty, I would think it is dry, which means you are dry fouling your plugs because they are too cold for your jetting. The first thing you need to do is get a new plug before you jet your carb. The BR8ES and B8ES plugs are somewhat of "catch-all" plugs in that they are neither too hot nor too cold to cause any catastrophic engine failures. They are actually one step colder than the original factory plug. Since your 250R is modified, it should make more power, which means it makes more heat, so a slightly colder plug won't hurt at all. The only difference between the R and non-R plug is an internal RFI suppressor, which suppresses the high frequency radio waves caused by the spark. If you don't run a resistor plug, you can hear the engine fire over a nearby radio. There is no difference in power output between resistor plugs and regular plugs, so don't get wigged-out if you can't find one. You can read up on some juicy spark plug tech from Autolite and NGK with these links. I have used both Autolite and NGK before, and I usually choose Autolite because they are much more economical than NGKs. The B8ES cross-references to a 4063 from Autolite, which is my weapon of choice. I still foul plugs every once in a while, and you will, too, but hopefully you can cut down on the frequency with some fine tuning of you carb. As far as cold and hot weather plugs, I do have my choices: the 4063. I don't change the plug, regardless of outside temp. Actually, you'll need to change your jetting in relation to the ambient temperature. It will be leaner in the winter, so you'll have to compensate for the increased air density. Once your jetting is dialed in for the conditions, you're good to go. I have two different jetting specs for my engines, with the average ambient temperature being the determining factor (60 deg F for me). If I need to tweak them in any way, I always know where I started from. The easiest way to find these specs is to jet the carb on a typical day for each season you will be riding in.

 

I sure do learn alot from your responses! thanks again..now I have some good reading to do. Usually people will give me 1 or 2 line sentences for responses but yours are awesome!..much in depth to the point and I understand too.
Since I have an oversized carb 36mm it probably is jetted too high..can I ask you this, being that mine is modified, is riding at lower rpm's like trail riding possibly fouling the plug since the gases don't burn as quick? I may have to lean her out a bit. I've noticed that the bike needs to be warmed up quit a bit before hitting into the powerband...once it does its very strong, but does spit and sputter sometimes not all just nearing the powerband in 2nd through rest of gears, this is why I will read the jetting article you gave me...should help out quit a bit.
First I want to fix the clutch problem even though it works ok..just one of those things that bother me. I want to be able to sometimes sit there in neutral or in gear without having to rev the idle up each time..annoying. I just need to now find the time to get to the motor...try again for tomorrow we'll see.
Take care....

 

It is possible that your jets are too big, but if the previous owner was only after top-end, they may be in the ballpark for that type of power. I usually notice that bigger carbs tend to make bikes a little more tempermental in the lower RPMs. This is due to the slower velocity of the incoming air charge. The bigger venturi allows for more air to pass, but it sacrifices velocity. Air volume and velocity are inversely proportional due to Bernoulli's Principle (more juicy tech at the bottom). That's why you see smaller carbs on engines built for bottom-end and midrange power. The velocity of the air coming through the carb has a direct effect on torque. This is because air actually has momentum. When you get a column of air moving, it will continue to move on its own until it runs out of energy or is stopped by another means, such as the reeds closing when the piston is coming back down. The smaller venturi also makes for a stronger "signal," which is the difference in pressure between the crankcase and airbox. As the piston rises in the bore, the volume below it increases, causing a pressure differential. High pressure always moves towards low pressure, so the air in the airbox rushes through the carburetor's venturi, drops in pressure again, draws the fuel out of the float bowl, and rushes into the crankcase, where it will wait for the transfer ports to open so it can go into the cylinder. A bigger carb will flow more air, but its advantage is only noticed at a higher engine speed. The signal will be weaker than a smaller carb given the same RPM. This is why low speed performance falls with a jump in carburetor size. The air moves slower through the venturi, and consequently, doesn't mix the fuel as well. It's not until the RPMs pick up until it mixes the fuel well. You can jet a big carb to work better at lower RPM, but it's better to step down in carb size if you don't really ride in the upper RPMs too often. For now, I would follow the advice of the guide and get your carb to where it will perform well for the RPM range you normally ride in.

Bernoulli's Principle articles

Explanation of a reed valve two-stroke's operation

 

So in essence if I mainly ride in lower and midrange rpm's it would probably be better off switching the 36mm for the stock PJ34mm or equivalent. What would you do in this case for woods and trail riding? down jet the 36 or go for a smaller carb? I agree with you that the jets are probably too big on this 36mm as the previous owner set the bike up for upper r's along with a bigger rear sprocket for more speed than low end. Which I'm also going to set back to the stock 13/39 sprocket sizes, I believe a 13 is on the front but a 45 or 46 on the rear right now. I've also heard that if I mix the fuel at 40:1 with a high quality race oil instead of the stock 20:1 that can make the bike run not so rich is this true?

I realize I'm getting off the clutch subject guys, so I may just start another thread...thanks

 

No need to worry about straying off-topic. It's your thread, and most go off-topic anyways.

If it were me, I would change the carb back to a smaller one to keep the venturi velocities high so the torque won't suffer. It will also be easier to jet for your riding style. Your interpretation of the gearing is backwards, though. A bigger rear sprocket will hurt top speed while making the bike accelerate faster. That's because the engine has to turn over more times to make the axle turn over once. The larger the rear sprocket, the longer the circumference of the gear. If the stock gear has 39 teeth and it's replaced with a 45, that's a 15% increase, so the engine has to turn over more times to move the trike a given distance on the ground. The quickest way to increase the perceived torque of an engine is to gear it lower (higher number of teeth on the rear). It doesn't actually increase the torque, but it narrows the powerband a little, and gets the engine on the pipe earlier. The stock 39 tooth sprocket is a little too tall for woods riding. I would say that a 41-42 would be a good balance between a manageable bottom-end hit and midrange speed. If you wanted to keep the 39 on the rear so you don't lose ground clearance, you could drop the front sprocket down to a 12. One tooth removed from the front sprocket is roughly the equivalent of adding three to the rear. Confusing, I know. About the oil, yes, you can run a 40:1 mix and the engine will live. Most mixture ratios were determined to take advantage of the latest oils (old tech now) and provide a cushion for reliability. A richer fuel/oil mixture won't really hurt the engine as long as it is not excessive. But, that was 1986, and it's now twenty years later. There have been tremendous advances in the petro-chemical industry, and high quality synthetic oils are readily available today for very reasonable prices. While I like the synthetics, my choice is still castor oil. Castor is an awesome lubricant, is environmentally friendly (if you're concerned about that mumbo jumbo), and smells great when it burns. OK, so that last point isn't really important, but it's true. When people talk about a bike running rich, it's usually because the jets are too big, not that there is too much oil in the gas. They think that reducing the amount of oil in the gas will lean it down, but this is a patchwork fix. Actually, the less oil there is in the gas, the richer the air/fuel mixture is. That's because there is less oil in the fuel when it is being atomized. That makes the air/fuel ratio shift to the right. Another confusing topic, yes, but re-read the jetting guide and you'll understand. There's a lot more to tuning a two-stroke than most people think, but it's not really that hard. Just keep records of what you do and you'll be fine.

 

Yeah, I believe this thread is very informative for any 250r owner wanting detailed advise, I know it has for me!
I think that is what my plan is for now, go back to the stock 34mm flatslide carb that came stock on the bike, but I now have to find one, at the top of your head would you happen to know of a good carb or site for my application? Its actually quit hard to find the exact stock carb PJ34mm for the 86 as you probably already know.
On the rear sprocket that was my fault on the info as I am now running the 39 on the rear and I believe the 13 on front. The previous owner gave me quit an array of extra parts he has collected throughout the year including many front and rear sprockets but i dont have a 12 for the front so I may take your advise again and purchase one instead of changing out the rear for ground clearance. He did give me the stock carb but looks like it was damaged near the air/fuel mixture screw and not usable in my eyes so that is why i need to shop for a new carb.
OH! I forgot to ask you..on the clutch basket removal, I hear they actually have a special tool for holding the thing from spinning while loosing do you have a suggestion as an alternative? Some people have stated that having someone put the bike in gear and hold down the brake works but others say that doesnt.
Thanks again for your replies...

 

Check here for some search results in the 3WW classifieds. There is a rebuilt 85 carb at the top of the list for $60 shipped. You can look around there, or hit up Ebay. It shouldn't be too hard to find a carburetor. I have used the brake-in-gear method many times before, and it works quite well. If the bike is in gear, the clutch won't move if the rear axle doesn't. If that doesn't work, another way is to put a pry bar though the fingers of the basket and brace it either against the floor or the frame. A buddy could even hold the bar if bracing it doesn't work. Just be careful not to damage the fingers on the new basket if you use this method to tighten it. A couple pieces of cardboard between the fingers and the bar help a lot. There are special tools for the job, but they are rarely used by normal people, so the cost doesn't justify them owning one.