RadarRacing

Mullets are still freakin awesome. Thats a bad ass rider for an ole guy. Lol..

I tgought the FAST clutch was alot more than $85 Rotax? At least the last time I checked. Its a really good clutch tho. Like said putting heavier springs helps alot. You probably dont even have to buy any, most guys have a bunch laying around if theyve been riding or racing for a few years.

Nick wrote "The dome shape was causing the motor to force the explsion towards the walls and causing all sorts of detionation problems. Mine had craked a transfer port. Problem 2 Problem 3 is not offical but this is what I've been told. 73mm cheetahs have such a large bore it compromises the integrity of the cylinders because they are so thin, I kinda agree but I had also been told its possable tolerances are sometimes pushed threw, and this means pistons sometimes are to tight and have no room to expand. In either case, my pistons left some pretty nice skid marks on the walls." Trinity has been told about their reverse squish problem and wrong dome design for years. Dont know why this has had to cost people thousands of dollars. To address "problem 3" a bigger piston and bore size requires more piston to wall clearance. A huge piston may expand a few thousandths while a small 50cc piston will only expand a thousandth. Most builders adjust for this. Snowmobiles and many 4 strokes have bores over 80mm to even 88mms and instead of 3 or 4 thousandths clearance they will have about 5 to 8. This sounds like a problem not necessarily... "Thats how it is with a big piston."

HaHa Matt. Its not a bad ad really. Not like guys with no price no location. LOL

You dont come anywhere near kansas city or omaha do ya. I'm really interested in it but I cant get myself to buy something I dont have my hands on.

Tree shots or duning 70 percent of the time and dragging a little I honestly wouldnt even port it. If you think of it as a drag ported cylinder that can get another 5-10 percent with porting and definately a little loss in lowend, I dont think I owuld port it further. Just my .02cents

First of all he wont need a spacer plate to run a 4mm supercub on a stock crank. He doesnt know what he's talking about that is all wrong. Running a 54mm stroke with a 58mm stroke will lower the port timing NOT raise it. Theres so many reasons that is incorrect, piston pin height would be wrong etc.

I think you are about right on at a 150 and 48 pilot with 28pwks. Unless the needle is an oddball I'd check coil, stator, etc for a problem.

They became a sponsor to take the heat off themselves.

I can say from experience from wreckin my bike last year drag arms are pretty dang strong. They'll take a butload of whoops and bumps no problem. Mine are Fireball and I'd say Stellars stuff is built even stouter. You'll be fine.

I know Loco this bike is killin me. That's an awesome bike Keyser. I keep thinking about cashin some of my crappy company stock and gettin a serval. Somebody buy this thing so I don't. I don't need it. You comin to this yrs oct ride at LS? Its only about 8 weeks. Bump for ya Keyser.

Sorry I read it wrong. It now has 188 and 120? For MX or woods riding I wouldn't change a thing. Do NOT raise the transfers to 128 with that low an exhaust port. 128 and about 194-200 would be drag timing numbers and suck balls to woods or MX ride.

Blowdown is the difference in degrees of crank rotation from when the exhaust port opens till when the transfers open. 188/128 would not have as much topend HP. 185/115 is stock so I don't know if your exhaust is even raised depending on how you measured. To answer your question port timing is the amount of crankshaft rotation in degrees that a port is open. If you want help with your setup you need to give more info about what type of motor you are wanting, drag,MX,dune, pipes, etc.

I'd start at 350 and work down. I've tuned a few bikes with pipes that needed 350s but some need down to 280 it really depends on the filters and the bike.

I hate to miss racing with you guys again. I'll be out of town. Seemed like a lot of good guys racing this year. I need a TNT day to get my bike dialed in perfect. Radar

Bump for ya. Dang that's a badass little bike for the $ I should sell some crap. .

That doesn't make sense to me about the gears you are running lean. Looky PILOT changes idle and ZERO throttle almost 95% NEEDLE changes just off idle to 3/4 throttle approx. Wide open throttle is almost exclusively MAINJET. Where are you lean?? Wide open throttle? Then MAINJET.

Thats a rigid drag chassis. A lay down chassis has the rider in a stance like superman. Head first.

Check any and all dumpsters at any business near you for a few weeks, maybe whoever stole it will dump it.

Mich , i think guys arent answering because they have absolutely no info as to what you have other than a 4mm stock cyl. If its a stock cyl with a stock head you can either lowere the cylinder and head with a thinner base gasket or have the head milled and raise the compression. Both those things do different things to power and compression. It really depends on what the motor really is. A motor with 90 psi may just be wore out, but we have no info. Also a motor with 90psi will barely start.

You guys are soo lucky you have such a government that cares soo much for you. Remember its always "FOR THE CHILDREN" first. Seatbelt laws, atv laws, anti gun. gun grabbers always wanna protect the children first as a back door way to start screwing you and pass more feel good "common sense" as they call them that infringe on you and your life. The pristine environment is another good arguement they use against atvs. Remember this crap when you vote!

I dont know if you traded bikes to see if you can beat him on the other bike or not but if his bike is just slower than yours then the cub needs more tuning, timing, different domes, etc. Also jetting plays a big part in tuning, if you have a well tuned 80 or 90hp bike and his build is slightly off he will have less HP easily. 3 mainjets sizes too rich is 10-12hp less on a gas 421 even tho the plugs will look really close to perfect. Theres a big difference if a 90 HP cub is only making 75 or 80.

IMO before you lowered the bottom of all of the ports you had room to lower the cylinders down to get your durations down to approximately 130 degrees. That is assuming the rings did not go above the sleeve. With transfers of 140 degrees your motor will not rev like it could and should. Depending on which pipe you are using with even transfers as high as 134 degres of transfer duration most motors will not pull up top at all. There would be ways to change your pipe and dome to compensate a little but at 140 degrees you are way off. As far as your dome and compression you will need to add about 4 more CCs to get down to pump gas compression on a 10 mil if you have over 200 lbs of comp. I do admire you for trying to build your own motor and trying something new. If you need the exact amount you would need to drop your cylinders to get down to 128 degrees of transfer durations I can calculate it on my other computer.

Looks to me like you are creating an air screw. Very good idea if thats drawing filtered air and adding it just like an air screw. Seems reasonably priced too for a set.

People who have no clue what they are talking about think a .020 or .080 is a "BIG BORE" which it honestly is NOT thats just a rebuild. You see it all the time with people selling bikes on craigslist. It will not be any faster unless theres other changes. If you buy a bike thats rebuilt I would see no reason to take the topend off to look at it. If it runs well and has compression at the kick starter then ride and enjoy. If its a recent rebuild with no time on it you may ask what caused the failure. Was it lean jetting, detonation or something of that nature that may cause you problems as soon as you buy it. If you were buying a drag bike with a cub or cheetah I would definately recommend taking the head off to inspect the bore or domes just as a precaution. .