charliechitlins

The seals should go in very easily. It sounds like something is interfering, or you've got the wrong seals.

I don't know if this helps, but I recently came across the only defective carburetor that I've seen...some sort of machining error. It was on a different brand, but the result was the bike would stall when the rear wheel got high. Drove me NUTS.

Only give it up to somebody else if you fail utterly and often! It's not that mysterious. The other measurement you need to take besides offset is concentricity (is that a word?) In other words, the hub needs to stay centered in the rim. Take some good, clear pictures (or make diagrams) before you take the wheel apart. Tap the spokes with a screwdriver and get a sense of how they ring, and you'll be able to tune your spokes when you are laced and trued. Ignore the ones that go "thunk"...you don't want that! Note how many spokes each spoke crosses, and notice if the inside spokes have a different bend from the outside spokes where they go into the hub, and if you have different length spokes. Install all of the 'inside' spokes first...on both sides of the hub. It gets a little messy with all those spokes dangling about. Before taking the wheel apart (if you're getting all new spokes, save yourself a bunch of time by getting the old spokes out with bolt cutters or cutting torch...just save 3 or 4 good ones)lie it on a flat surface on whatever side keeps the rim up off the table. Find something that will be the right thickness to put under the rim in 3 or 4 places so you can shim it up to that height when you have re-laced. After the spokes are in, you can lie the wheel on a flat surface and shim up the rim to the proper offset. While you tighten your new spokes, keep measuring the rim-to-hub to keep it centered, and make all the spokes just barely finger tight (lube all the threads!). Theoretically, now your wheel is true, and all you have to do is tighten the spokes evenly. It won't be the case, but it's a good start. Your swingarm (or front fork if it's a front wheel) makes a great truing stand. You can install the wheel and tape one of those little red straws from a spraycan to the swingarm to use for an indicator. Spin the wheel and watch the rim/straw relationship for side-to-side and up-and-down. Use a marker to mark spots where you want to adjust. Always be aware of where the valve hole is when you're going around tightening each one evenly, so you know where to start and stop. If you have any up-and-down, get rid of that first. The rim will move side-to-side depending on which side of the hub the spoke you tighten comes from. Let us know how it goes! I can do a complete wheel in about 30 minutes when I'm in practice. An hour when I'm not. My first few took several hours each.

You can't do it with a feeler gauge like that. And, your piston is cam ground (oval)so it makes a difference if you measure fore and aft or by the wristpin hole. BTW, a piston is smallest side-to-side by the wristpin (gudgeon pin). What you can do is put a piston ring about 1" up from the bottom of the cylinder, square it up by pushing it in with the piston, and measure the end gap. There will be very little wear there because the rings don't go down that far. It will be close to standard bore. Then push the ring to the middle of the cylinder and check the end gap. Do this in a few places. Now...this will show you the change in circumfrence. In order to translate that to the change in diameter, you have to remember your High School Geometry and divide by pi. As for the crank, you need to get the spec for endplay (side-to-side), and make sure there is no up-and-down play in the crank or the connecting rod. Don't worry about side-to-side play in the rod. If your unfamiliar with this, it may seem grave, but it's standard.

You sure you've blown the right way?

Beautiful work. I love a good special. I seem to remember a guy (bloke) in the UK named David Silver with a lot of Honda spares.

Nice job!! I have found the stock Sherco bars to be very durable and considerably less expensive than Renthal.

Sorry to hear about your knee. Try to keep that humor. You'll need it. As far as I can tell, the transplant heals faster, but the graft is stronger. My doc is a fellow named Russell Warren from NY hosp for special surgery. He's basically the granddaddy of the ACL and he still does the NY Giants. He uses the graft... 'Nuff said.

You mean fresh silicone?

A piece of PVC pipe as close to the o.d. of the seal as possible works great. I usually just place the old seal atop the new one and tap gently with a hammer. The tool worth buying is a seal puller...very inexpensive, and it will keep you from buggering stuff up from prying seals out with a screwdriver. The damper assembly (innards) may turn if you don't use an impact and the bolt won't come out. Sometimes there is a hollow in the top of the damper assembly (sometimes even a hex), and I have tapped (gently) a broom handle into this to keep the assembly from spinning. I haven't needed seals in my Sherco for years, so I've forgotten what is in there. If you don't have a compressor, you can buy an electric impact gun. You'll find a million uses for it.

I like Dabster's pic with the rims with the colored centers. I once worked on a Vincent that had chrome rims with black centers and a red stripe separating the two. Very classy.

I think there is no hurry, now. I figure that the companies without the support of the big japanese factories are taking their time and saving their money.

Actually...it does a 3rd thing. It changes the shape of the combustion chamber, too. It is my understanding that the shape of the combustion chamber on this bike (the 350, anyway...I don't know about the 250) caused a strange flame propagation, and something like a double ignition...and one of the '2' ignitions causes a knock. So...I guess the compression change has something to do with improving the burn, but the primary problem is the actual shape of the squish area. When folks started to put high-domed "pop-up" pistons in Harleys, they found that this divided the combustion chamber in 2, and caused a similar knocking. The problem was solved by adding another sparkplug on the other side.

Milling the head or removing the gasket (I use 'fake chrome' spraypaint when doing away with gaskets) will raise compression.It's my understanding that the knocking on a TY is caused by the shape of the squish area, which causes a weird flame propagation. Raising the compression seems to help it burn a little better. I suppose a good welder/tuner could reconfigure the head to work better.

Penetrating fluid.

So...we can assume that granny already knows how to suck eggs?

D'oh!! I'd still be concerned about loosening the fit there.

Both of the above are correct. Pistons are cam ground. They'd be cheaper if they were round! .001"/inch is a good estimate if no specific info is available, but I imagine the stock spec and wear limits are available for your machine.

Just a note on knocking the stem through the bottom yoke... I change a fair number of Harley valve guides (stay with me ), and even after heating the head (aluminum), I usually need to replace the worn guide (cast iron)with one with an O.D. that is .001" or even .002" larger. This is just what happens when you press a hard thing out of a soft hole (ouch!). It takes some aluminum with it. I would doubt that the factory intended for that stem to come out of the yoke in the course of its life.

I'd be wearing an ermine cape, carrying a gold scepter and insisting that people call me "Your Highness"...including my mother!

Wait a second..... Teaching granny to suck eggs?!?!?! That's quite a visual. What the hell does it mean?

How did you measure the cylinder and piston? If you didn't use a micrometer and a bore gauge, you didn't get an accurate measurement. You can get a pretty good idea of how much cylinder wear you have by checking the difference in ring gap between the bottom and middle of the cylinder.

You could try wedging it off with a cold chisel and hammer (no wisecracks about me being a Harley mechanic!). Keep the chisel off to the side so the sharp end won't hit the stem. Work back and forth 180 deg. apart to get it off evenly. Most bikes have a larger portion at the bottom of the stem, so you'll only have to do this for the height of the bearing, not the whole stem. You could use some heat, but try to localize it on the bearing. Getting the stem hot might make things worse. You may end out trashing the bearing because you are applying force to the outer race and/or rollers. If I designed a lower clamp, it would have 2 holes so I could use a punch to drive the bearing up from underneath. I have had to cut many off.

I hope a mechanical list-member buys it so we can read about all the tricks.

There is a slight difference between a Champion and an NGK thread. Most noticeable when the thread in the head is a little worn. If the Champ works, go with it. Autolite are good, too.