dlnoss

I have dealt with Nate at More Torque, Dan at Patriot, Cameron at Redline, plus Jim at Passion. All these guys know their stuff.

WOT for a mile? I'd be suspect of leaning out, possibly detonation with the loose plug.

The reason it cools better involves more than the coolant capacity of the head. The flow characteristics are also improved. We did run some tests doing sand drags at Little Sahara in Oklahoma. They ran 55 degrees cooler than the stock head. Your results could be a little different because of jetting but they definitely run cooler than stock heads and many other brands of aftermarket heads. I'm not trying to talk you out of milling your head, just answering some questions. -David

It would be normal for the compression to increase that much going from 21cc to 18cc. That's a little too much IMO. You should have a welded crank and definitely need to run race gas. It sounds like you must be close to sea level. You will notice more bottom end power but will lose some rev.

The Noss heads run cooler than stock, most brands probably do. For sea level, 21cc domes will work with premium pump gas. If you want to run race or av gas, you could install smaller domes for even more performance.

My chart could be on the high side a little. With either number you would be okay with premium pump gas.

It's a 10% discount which makes it $234 + shipping for silver with domes, $247.50 + shipping for anodized colors with domes. 20cc domes would be fine with premium pump gas and a stock crank at 1200'.

I'll ship to UAE. I've shipped a few heads there. PM me.

You could run 20cc domes fine with premium pump gas. 19cc would probably be okay but pushing it a little. I prefer the Noss head but my opinion is a little slanted.

What is your location/elevation and other mods?

On a good day I have a signal strength of 75 to 79. The just switched our transponder which increased the signal strength. It was running 45 to 50. It didn't speed the system up any. We have it networked and it seems pretty slow. Have you tried any of the tweaks on www.dslreports.com or www.copperhead.cc? Running Ad-Aware frequently seems to help. If I could get DSL here, I would.

You should be able to run 21cc domes with good premium pump gas, if you go the aftermarket head route. You should get a 2 to 3 horsepower and improved throttle response and low end power. Not only is your compression increased but the design of the aftermarket dome is better than that of the stock head. It will make a difference that you will definitely 'feel'.

The only time I've ever removed the tank was with the previous style head where the studs had to be changed. If you have any questions (before 10:00 pm CST) give me a call. Just make sure the tops of the cylinders are clean and the orings are held in place with grease. Put a little RTV on the threads before installing the nuts. Have fun at Sand Mountain.

It's difficult to clean out of the oring grooves if you ever need to and can make the orings non-reuseable. It also can keep the orings from seating properly if it sets up before assembly.

Don't use any type of gasket sealer. Use grease. If they still don't want to stay in place use stickier grease.

Cooperland is very nice. Nice track, well maintained, nice facility overall.

I'm not sure I understand but the hose doesn't slide all the way up on the fitting, only about an inch. Call if you want. -David

Is it a stock head? It could be warped or maybe the head and/or cylinders weren't clean when installed.

Sorry to hear about it Jim. That's a bad deal.

I talked to a dealer today. He said that Yamaha told him that he wouldn't get any more Banshees. What he had in stock was it. There would be no more coming. We will see.

You will need 21cc domes at sea level with 91 octane. Any smaller will require more octane to avoid detonation.

It's a lot of work to make them from scratch. I make up a couple hundred of the dome tops at a time. The bottom side requires the oring groove, the squish clearance (usually .035 - .040), the squish width and angle depends on the power characteristics you want and the pistons you are using. .25 - .40 are common widths, usually around 13 degrees for Banshee pistons. The bowl shape and depth also affect power characteristics and, of course, volume. The bottom of the spark plug needs to be flush with the top of the bowl. In other words, you don't want to lower the spark plug down in to the chamber to decrease volume. These are just some ideas to help you.

Check some of the simple things first. Carb slides synced, slides in correctly and not sticking, cross tube connected. Good compression on both sides to make sure the domes orings sealed properly. It could be a leak around the reeds or reed spacers. If you made all the changes at once, you might back up like remove the reed spacers and/or reeds and see if the problem goes away.

When removing the head, it's not real important. The numbers are on the stock head if you still have it. Work from the outside in when loosening and inside out when tightening.

18cc might be pushing it some at that elevation with pump gas.