44mm Factory? big bore (I measured the piston with caliper)
"Lightened Flywheel" I removed 2 fins skipped one
Port matched the exhaust port to the pipe
Modified the stock exhaust cut the pipe removed the "extra" header inside shortened the header pipe by ~1" but did nothing with the "belly"
Stacked two stock tin reeds on top of eachother
Slotted the magneto pickup and advanced the ignition timing slightly
Base Gasket Gone, Yama-Bond'd it. (it is not leaking though)
The bike has a six tooth front sprocket and stock rear sprocket. the bike runs good but seems to hit a wall when you get to the top speed. I took the gps with me and I was getting 27mph. After each of the mods listed I did the test with the GPS. 27 is all I am getting. Nothing seems to change anything. I think I should be getting more out of her but maybe not? I know i need to bump up the front sprocket. What do you guys think may be the problem? It seems to run better when it's cold then after about 30 seconds it slows up. I don't think it is rich because it's about 30 degrees here. Anyone have any ideas? I can get measurements etc if that would help you diagnose.
I did some math and at 27 mph the engine is reving to ~9300 rpms. I think it pulls very good and runs clear and sounds good until it hits that top speed when it falls. I don't think it runs out of power, I just think it cannot rev any higher.
ya your gearing is at stock for stock engines yours is not stock so you need to change the gearing to get anything out of it. for fun i would change mine to stock and it would scream though the power bands but would hit the wall you are talking about. to get what you are looking for the key is in the gearing. you can get cheap ones at davesmotors.com and get them shipped the next day. good luck hope this helps
Definitly try an 8 th, or at least a 7.
And putting 2 metal petals together, does not a fiber reed make! Try a real fiber reed, in the past I got used dirt bike reeds and cut & drill them to fit nicely on the reed block, they won't flutter at high revs, this was before they had them on the market. Now it's the thing to do. If you want to get fanncy then make oval holes (6 by 10 mm) in the fiber reed, and place the metal (.006 in.) reed over the fiber one on the crank side of the fiber reed. This is the way Boysen makes their power reeds.
I have not rejetted it yet. I do not know if it is running lean or rich. Can I read the plug the way I would with a snowmobile? I don't think it is running lean because, in my experience, when a motor is running lean it just falls off when you open the throttle and doesn't ever kick back on. This one is kicking and sputtering the way a rich engine would, but I don't think it is rich because it is 30 degrees out. I ordered a new 8 tooth sprocket. I will see what a difference that makes. It feels to me that the jetting is good but that when the cag hits 27 there is a wall the engine hits as I said before. How do you know what to re-jet to? Are there flow rate numbers stamped on the jet?
I'm actualy having the same problem with my x1..well it seems like it, like I'll tune my bike and then run it and it'll be great. then I'll even be going down hill and it'll seem like it hit a wall. It wont rev any higher or anything it's weird, it's got a v-stack/air filter, skinny pipe, and NOS. I don't know if this is just the bike or what it is
Sounds like the reeds are fluttering at top end, or you need to rejet. Since you have a "double set" of reeds in there, I'm guessing it's probably the main jet that needs to go up a size or two, maybe the petcock not flowing enough gas. Order the jetpack from Dave's Motors, and rejet to a ..... try a 70. also, since you're there, get one of the inline fuel shutoff valves, do the petcock mod, and install the inline fuel shutoff.
On your reeds, you can also try cutting the top one (the one between the curved reed stop and the stock reed) into the same shape as the top reed on a Black Widow triple stage set. I did that on several of my bikes, works great. (Search for davation's cheap triple-stage reed mod - that's it.) You can also shave the underside of the reed stop down a little so the reeds open up further. Make the tips of the curved piece a little sharper, then smooth out the curve from there back to the base. Sorry, no how-to on that one - you just havfta kinda eyeball it .....
