Ruko

Anyone know how to get ahold of T-Rex or Cheetah direct?? I can find lots of places to get there finished cyliders but I can't find how to get ahold of them directly.

A blank casting is an unfinished bare casting. Just the aluminum casting with no sleeves or machining done to it yet. A builder a buddy of mine knows has some ideas and wants to experiment.

Anyone know where to get blank cylinder castings?? Preferably a mono block.

If it's still stock don't bother. You only need more octane if you raise your compresion. Just stick to pump gas until you do some mods, and then run race fuel or 50/50 mixed with premium.

I run CPI inframes and for some of the riding spots around here I need spark arresters. Does anyone know of any spark arresters that will fit CPIs?? Also from what I've seen spark arresters are just a metal screen across the tube in the silencer, is this true?? If that is all they are it should be easy to add. Will that work or no?? Thanks for any info

I have Alpine Star tech4 S boots which were supose to be made for ATVs. They are little shorter than most boots for birt bikes. They're great for me but I did have to adjust my shift lever when I first switched to them. If I remember right I moved it up one tooth on the spline. The boots are great and I have no problem shifting. They were cheap too, that's always a bonus.

Guys around here use them in sleds a lot and I have one for my banshee but I haven't installed it yet. The position of the exhaust probes makes a big diference on the exhaust temp reading so you have to do some testing to get the temp you want. You have to do plug checks until you have it jetted just right, then check the temp on the Digitron. That becomes your baseline so when you have to jet in the future you adjust up or down to get back to that temp. It's way easier than doing plug checks once you find your baseline.

Thanks for the tip Lightninn. I'll give it a try.

I run Turf Tamers now and they seem pretty good but what do you guys mean by "grooved " ??

The Toomey web site has some dyno sheets for different pipes but I don't know if you can belive them because of course the Toomey's make the most power on all of them. The CPI's are a higher rpm pipe than the Toomey's though so they have not yet peaked on the charts they show. "www.toomey.com"

Ive got the 420 big bore done and there was a big power increase. But at the same time I got it ported and a new head with smaller domes so I don't know how much of the increase was due to the bigger bores. I am very happy with it though. I started with T5 pipes it had all kinds of mid range, I could pick the tires up in every gear like a four stroke, and it was way more forgiving for hill climbing. If your rpm's dropped a little it would keep pulling where before I would have died out. I then changed to Cpi pipes and have much more top end but still way more mid than it had before the 420. I would recomend the 420 if you want more power and you are on a budget as it is about the cheapest way to go, but I have been told the strokers will make more power, however they are a lot more money as well. Hope that helps

Even on the pistons which had the rings break there was no sign of wear just the scoring from the broken ring. I don't see how it could be a lack of oil as I was mixing the 100-1 Opti at 58-1 so it was almost double the oil it called for. Also the third engine this happened to was running Amsol 2000 at 50-1 just as it calls for. So it happened with 2 different oils mixed at 2 different ratios. Also as far as excessive wear, while it is possible with mine and the third engines, the second one was on a new machine, only 6 months old, with only about 30-40 hours on it and it had never been apart. He was also running Opti at 58-1 (almost double what it called for). I know another guy up here who has run Opti at 75-1 for the past 6 years and has never had a problem and has never been into his engine for any reason. So it just doesn't add up for me new machine at 58-1 and wears out the locater pin after 40 hours different machine running 75-1 for 6 years with no problems. Because of this I don't belive it was a lack of oil problem, I also don't see how a new machine could have excessive clearance after 40 hours. I don't mean to sound ungrateful for all your help and suggestions, but no explaination seems fit all three cases. I know this is a tough one. It has us stumped as well as the local shop here in town. Thanks again for all your help

Unfortunately we did not check the clearance on the old pistons just on the new ones. But the pin did not come loose and come out. On the stock pistons the pin is on the top side of the groove with the bottom half of the pin into the groove and the top half above it. The pin stayed in place but the bottom half was worn flat to allow the ring to turn. The Wiesco pin was also still there but the end was worn off. Is this the same problem of too much clearance?? If so how much clearance is too much??

When the first two did it we were using Opti-2 synthetic. It says to mix it a 100-1 but we were mixing it at about 58-1. We have since changed to Amsol 2000 just because a friend of ours is a dealer for it. We are now mixing it at 50-1 as it says on the bottle. The third was running on Amsol when it happaned. There was no wear or scuffing on any of the good pistons to indicate a lack of lubrication, so I think the mix was OK.

The two stock engines had never been apart. They were stock out of the box from Yamaha. If this was a Yamaha ring problem you would think it would be more common. There has not been any responce that anyone else has had this happen so I am starting to think it must be something that we did. The three of us ride together all the time and all three of our machines did the same thing. Unfortunatly we don't know how to prevent it if we don't know what caused it. All your help is appreciated Thanks again

Mine was an 01 with stock bore and stock piston. The bores were still good enough to just hone them and reuse them. The next one was an 03 with stock bore and piston, and again it was OK to reuse with just a hone. The last was a 96 with .020 over wiesco pistons. It put a pretty good groove in the cyl. so he is having it rebored. This last one just happened a couple weeks ago so he hasn't got it fixed yet but the cyl's are out getting bored right now. When mine happened it was all stock with T5 pipes.

Has anyone else had this problem and does anyone know how to avoid doing it again?? OK here's the story. I was riding along no problems and started losing power. Checked the exhaust and it was missing on one side. Went home and did a compression test, I had 120 and 65. Not good, but not a big deal yet. Pulled it all apart and the little pin in the top ring groove that is suppose to keep the ring from turning was worn right off. So the ring turned in the groove until the end hooked the edge of the exhaust port and broke off. Didn't do much damage so I got away with a hone and new pistons. When I took it into the local shop to get it honed the guy said he had never seen that pin wear off like that so we figured this was a fluke one time deal. Within six months two of my buddies have had the exact same thing happen so we are starting to think this is no fluke. It happened with two stock pistons and one Wiesco. So I got a few questions. Has anyone else had this happen?? Is this a common problem?? If so what causes it?? And how do you prevent it?? Thanks

I had the same thing happen, the top ring on one piston got hooked on a port. It turned over fine, started and ran fine, but was missing on the one cyl. because it had low compression. I would do a compression test, if for nothing else than to rule it out. A compression test only takes five minutes and could save you a lot of screwing around.

Thanks I'll change those hoses and see what happens

I have a problem keeping coolant in my rad. I have moved the overflow bottle up front and run an oversize Magnum rad with Engine Ice coolant but it still pukes it all out. I have a temp gauge and it runs between 140-150 so it is not overheating. In fact it starts dumping all the coolant out before it even hits 120. None of the other guys I ride with have this problem and they are still using stock rads. Any suggestions??

Do a compression check to make sure your rings didn't get hung up when you assembled it.

Who needs bottom end? Just keep her lit!!

First off get rid of your shocks. Use aluminum square tubing with your holes 11-12 inches apart. This will lower your center of gravity and take out all the body roll to give you much better launches. Makes for a rough ride but you won't even notice when you're kick'n ass. For trail riding just put the shocks back in.

if you want it a short as possible wy are you running a +6??

What's the deal with these shortened swingarms giving you a better holeshot?? Is it like the old altered drag cars that moved there rear axels forward to get better wieght transfer?? If so wy do all the drag banshees have extended swingarms instead?? Would it work to run a shorter swingarm and then a wheelie bar to keep the front end down??