Few issues need some help

[cutt]

Ok so i got a 1990. When going full throttle it stops at 10k rpm and stays there, doesnt go up or down like i am hitting a rev limiter. If i ease into the throttle it will hit 12k all day long, i have changed plugs, cut a little off the wire, cleaned out the jets and floats on the carbs, new fuel filter but still does it. Any idea's why? ALSO the guard that sits on top of the swing arm (not the plastic chain guard) but the one that sits directly on top of the swing arm well mine was missing when i bought the bike, ive tried to find some on ebay but havent had any luck, anyone know of a way to make one to fit it or where i could buy one? any idea's would be great. The chain is starting to take chunks out of my swing arm right beside my shock.

[Rooster]

For the guard it is an anti wear piece of plastic, and you may have some luck going deeper into some of the e-bay stores on some listings as they don't show all they have just the piece they want to sell and some guys are parting out whole bikes. In a pinch my buddy found a plastic cutting board cut a strip from it on a table saw, drilled holes and counter sunk the heads and made his own.

[cutt]

hell yea thats a hell of an idea i wouldnt have never thought of using a old cutting board. Thats exactly what ima gonna do thanks alot man! i really appreciate it. Thank you very much! now if i can figure out why it wont go past 10rpm at wot.

[Stig]

I have a few spare swing arm guards. You can have one for postage if I can dig it out

[cutt]

Well i have now replaced all fuel lines replaced air filter, all clamps connecting airbox to carbs and carbs to head, took carbs off and cleaned them completely with no luck changed the plugs again nothing cleared it up, and im out of time to fix it as i am leaving for premier truck driving school in a few days. So there is a shop a few towns away from clarksburg that i am gonna take it to. I just dont have the time to mess with it right now, so hopefully this guy know's his stuff and can get it running. Stig thanks for the offer bud i do appreciate it, but i actually found one from a guy a couple days ago. Well guys wish me luck hopefully this guy up here can fix her up for me! Ill let yall know how she does when i get back in a few months!

[cutt]

So came home from work picked my bike up. The guy said he couldnt figure out why it was doing it. BUT he figured out how to kinda fix it. the bike will not run properly with a airbox on it. we took the airbox off (open carbs no filter) and it runs like a bat outta hell. no misses it doesnt hesitate at all! so i am now in the process of finding some 58mm cone air filters to see if i can put them on there. IF that does not work, and it falls flat on its face again like with the airbox on it What should i do then? thanks

[Lastmile]

Sounds like your air to fuel ratio may be off. Sounds to me like its running rich. I'm not sure what those bikes standard jet sizes are, but I'd start there. A lot of people think by throwing in a stage three jet kit they will turn their bike into a race bike. How did your plugs look when you pulled them off?