Motorcycle Tech Questions and Answers

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Hard case
I recently came across a deal I couldn't pass up, on a roll-around hydraulic jack stand. When I got it home, I lubed those damn squeaky wheels and got it positioned under my '06 1600 Nomad. Then I see that the engine case hangs down below the frame. My question is, can I jack up this 800 lb. machine with the jack against the engine case and not the frame? Can the case support all that weight? I am afraid to try it for fear of cracking the case or creating a leak. What can you suggest? Great magazine, by the way...
Joe Gass
Via e-mail

While picking the bike up by the case isn't the preferred method, it's unlikely it'll do any damage. I've done it many times myself without problem, so if that's the only way you can safely lift it, that's what you'll have to do. A better method might be to build a small cradle or use pieces of wood to shim the jack pads so they contact the frame instead of the engine.

Worldwide Wheels
I'd like to replace the spoke wheels on my Yamaha 1100 Dragstar (V-Star in the US) Custom with billet wheels but they're difficult to find in the U.K. and the cost approaches that of the bike itself. Is there anyone on your side of the pond that makes them?
Via e-mail

There's so many guys making wheels over here it's silly. Just troll the web sites, using "motorcycle wheels" as a search phrase, until you see something you like. As to the prices, some are reasonable, others not so much, but don't forget you'll also be paying customs and shipping charges, along with any UK taxes, which will up the ante.

Passing Gas
I am a relatively new (2 years) rider approaching my 64th birthday. I ride a 2006 Honda Shadow Sabre (1100cc engine, stock) and a 2004 Honda Shadow Aero (750cc engine stock). I generally ride around the city, but have been known to take 2-4 hour road trips up north. I regularly fill my gas tank with premium gas and am wondering if I'm doing any good or harm by doing so. I'm not worried about the extra cost in using premium, but wondering how it affects my engine, my performance etc.
Bill Hartman
Via e-mail

The rule of thumb is that engines only require enough octane to prevent detonation. Normally running a higher-than-required octane won't hurt anything other than your wallet, although in some cases it can make an engine hard to start, or give it a rough idle. As far as performance goes there is no advantage to be had from using a higher than required octane, so bottom line: fill up with the manufacturer's recommended grade of gas and save the difference for burgers and fries.

Royal Whine,br /> I used to work on motorcycles for a living but now prefer just to ride them. I still have friends wanting me to fix their problems, and I usually end up doing it. A friend's 2007 Yamaha Royal Star final drive makes noise, and I hear many Yamaha riders experience the same problem. I have rebuilt a number of final drive units on Yamahas (70's & 80's) and BMWs way before anyone else knew what shaft drive was. This sounds like the pinion gear is shimmed too tight against the ring gear. Whines going down the road and when you lift it, make a terrible growl thru a stethoscope. Are you familiar with this problem, and if there is a fix or if it can be re-shimmed? The dealer tells him it is normal and refuses to look at it. Any help would be appreciated.
Via e-mail

I'm not aware of any specific or generic problems with the Royal Star's final drive, but that doesn't mean there aren't any, of course. I did a quick internet search and nothing jumped out at me, so if you have info to the contrary please let me know so I can find out what's going on. All that aside, shims are available through Yamaha's dealer network for both the ring and pinion so achieving the proper float shouldn't be a problem.

Plugging Away
I have purchased plugs for my 2006 Star Stratoliner. The plugs are standard for my bike, except that they are from a company called Emission Performance. The plugs are cryogenically enhanced (frozen to 350 degrees below zero). The claim is that they will give up to 80% less emissions, 20% better fuel economy, and 15% more power. My mileage has increased by about 2 miles per gallon, but nothing else.
Mike Dorn
Via e-mail

My opinion is that you got hosed. I'd venture to say that had you installed a new set of standard plugs you'd have received the same two-mile-per-gallon increase, and saved enough on the cost of the plugs to have a beer and a good cigar.

As a point of discussion, a spark plug cannot create horsepower; it can only utilize what's already available. If under ideal circumstances an engine makes 100 horsepower, then you can install all the plugs you want and you'll still only get 100 HP.

In theory, a very low resistance plug would decrease the amount of energy it takes to fire the plug thereby providing slightly more energy at the plug's tip, but in reality, the differences would be so slight they'd barely be measurable. As for the manufacturer's performance and emission claims, well let's just say it seems like a stretch.