Service

SERVICE

Paul Dean

Wiring gone haywire

I'm going to do some rewiring on my 1973 Norton Commando and my 1961 Harley 250 Sprint. I talked to my landlord, an electrician by trade, and he said I should use 12-gauge copper wire because it will flow a lot of juice. A biker friend of mine, however, said that doing so could cause an impedance problem, and that I might need to use a very large battery with a high ampere rating in order to use that size of wire effectively. Who is right?

CHAPPELLMJ Posted on America Online

If you're going to heed either of those two pieces of advice, listen to your landlord, even though his sug gested wire size, 12 gauge, is consider ably larger than what is needed for most of the electrical circuits on your two bikes. And no matter what your biker friend tells you, there is less im pedance (resistance, for the electrically challenged) with larger wire, not more, so you don `t need a bigger battery to deal with it. For evidence, consider this: The main ground "wire "for prac tically every electrical component on practically every motorcycle and auto mobile is not a piece of wire at all; it the entire frame-quite a bit heavier than 12-gauge wire.

For most applications, the motorcy cle manufacturers generally use 14or 16-gauge wire, opting for heavier stuff only where the current requirements warrant. Their reasoning is simple: Heavier-gauge wire also is heavier weight-wise, is bulkier when bundled together in any quantity and costs more. But, if you ’re willing to deal with all that, go for it.

Smokey the unbearable

Ever since I took delivery of my 1997 Harley-Davidson Ultra Classic in June of 1997, the bike has burned oil at the rate of about V2 quart every 500 miles. I can smell the oil burning when I back off the throttle, and my riding buddies can see smoke coming out of the tailpipes. The engine also tends to overheat in traffic to the point that the oil-pressure gauge reads zero and the oil light comes on. Eve written to Harley and returned the bike to my dealer numerous times, but Harley claims the fuel-injected models take longer to break in and that what I am experiencing is normal. I now have over 4000 miles on the odometer and the problem still exists. Do you think this is normal? If it is, why have I never read anything about it in your magazine? James F. VeltO

Weirton, West Virginia

Speaking of blowing smoke, whoever told you that fuel-injected Harley models take longer to break in than the carbureted ones was doing just that. The critical break-in components-pistons, rings, bearings, cams, valves, valve guides, etc.-all are exactly the same pieces on the injected and carbureted H-D models. They don’t know if they ’re being rotated or shuttled up and down as the result of fuel that came through an injection system or fuel that came through a carburetor. In any case, 4000 miles is way beyond any reasonable break-in period; if those components aren’t broken in by now, they never will be.

In and of itself, an oil-consumption rate of one quart every 1000 miles is on the high side of acceptable but still within what most manufacturers of VTwin engines would term “normal.”

So is the low oil pressure you observe at idle; that’s not a critical condition on an engine that has a roller-bearing bottom end and a low-pressure oiling system. But if the engine is smoking badly enough that you can smell it and your fellow riders can see it, there ’s a problem somewhere that needs to be addressed.

And you should not have to pay for > its remedy. When you spend $18,000 for a new motorcycle, you deserve to get one that doesn’t leave oil smoke trailing behind. Keep complaining to Harley-Davidson, the factory. And tell them that you read it here.

Gimme a brake break

I recently bought a used ’81 Honda GL1100 at a great price, and it only had one problem: The front brakes locked up intermittently. It seemed to be associated with heat: The hotter the day, the more the brakes would lock up. I exchanged all three brake lines with new ones, but no help. I rebuilt the master cylinder with new parts, but again no help. I took apart both front calipers and inspected them, and they looked okay, but the brakes still lock up. I can unlock the brakes if I crack open one of the bleeder nipples on either caliper, or if I just sit by the side of the road for about 20 minutes until the brakes release. I think the problem is in the master cylinder, but I can’t figure why; I’ve put brand-new parts in it. What do you think?

Ray Loupenay Corpus Christi, Texas

If you have properly completed all of the repairs you described, something is preventing the master-cylinder piston from returning all the way to the beginning of its stroke. It ’s my guess that at some point in this bike ’s 17-year history, someone replaced the front-brake lever with the wrong one. Many levers look alike and will bolt up to the same lever bracket, but if just one of its critical dimensions is slightly off the wrong lever could prevent the master-cylinder piston from returning all the way.

Here’s how it’s supposed to work: There’s a tiny hole between the master-cylinder reservoir and the piston bore, through which brake fluid passes to 1) allow additional fluid to enter the braking system to compensate for normal brake-pad wear; and 2) allow fluid in the system to return to the reservoir when pad-to-disc friction heats the fluid and makes it expand. If the piston can’t return far enough to allow its leading edge to just clear the hole, the fluid will be trapped in the system; and when the fluid gets hot, it will expand and lock the brakes.

Install a front-brake lever that you know was designed for the GL1100 and the problem should disappear. I’ve just purchased a 1998 HarleyDavidson Road King and have questions regarding the correct motor oil to use in it. The dealer says to use only H-D oil, preferably 20w50. The owner’s manual indicates that if oil needs to be added and H-D oil is not available, to use an oil rated for diesel engines (CE rating or better, preferably 20w50) until a change can be made back to 100 percent H-D oil. My questions are: 1) What is the difference between H-D oil and another name-brand oil of the same weight?

A slippery subject

2) As the Harley has a spark ignition, a relatively low 8.5:1 compression ratio and does not share oil with the transmission, why must an oil rated for diesels be used in lieu of H-D oil?

3) Why are the heavier, 20w50 oils preferred over 10w40 or 15w40 oils, whereas my ’91 Nighthawk 750’s owner’s manual called for 10w40 year-round? Any information and insight would be appreciated.

Robert B. Kamping Lawrenceville, New Jersey

By insisting on the exclusive use of its proprietary oil, Harley-Davidson is simply trying to ensure that its engines are lubricated with oil that the company absolutely, positively knows will perform well. And, of course, it’s no secret that the Motor Company has long sought to control as much of the Harley aftermarket as possible, including oil and other service items. Truth is, though, the difference between Harley-Davidson oil and most other comparably rated top-line motorcycle oils is very little, if anything. Of the many Harley riders 1 know, most do not use H-D oil, and they’ve had no more or no fewer oil-related problems with their bikes than riders who use H-D oil religiously.

I believe that Harley s recommendation of CE-rated oils in lieu of H-D oil stems from the fact that diesel engines face lubrication challenges similar to those in a Harley engine. Diesels generate tremendous heat in combination with huge pressure loads that can penetrate the film boundaries of lighter oils, especially at high temperatures. Roller-bearing bottom ends, such as those in Harley engines, place all of the downward pressure of combustion on just a few individual rollers at any given moment, rather than spreading the load over a broader area as in a plain-bearing bottom end; this can allow the rollers to penetrate the oil film more easily. Your Nighthawk 750, however, had a plain-bearing bottom end perfectly suited to 10w40 oil.

The glue from hell

My dearly beloved ’97 Suzuki Bandit 1200 has incurred a rather sticky problem dealing with the removal of the “Bandit 1200” decal from its fairing. The decal itself was easy to get off, but the remaining glue has proven impervious to removal with sundry chemicals including cooking oil, hair spray, tar remover, gasoline, methyl hydrate, acetone, etc. Is there a simple solution for the eradication of this seemingly invincible glue without damaging the paint, or am I “stuck” with it? Alex Robertson

Alex Robertson

Richmond, British Columbia, Canada

The best thing I’ve found for removing glue left behind by decals, duct tape, price tags, warning labels, etc. is a product called Goo Gone. It’s cheap, comes in an 8-ounce bottle, and is available at lots of hardware, auto parts and camping stores. I’ve gone through more than two bottles of the stuff and have never found it to harm paint in any way. It also removes lipstick, chewing gum, crayon marks, shoe polish and a lot of other messes. Okay, commercial over.

The Long Ranger

I own an ’86 Honda Shadow, a VT500C. I really love this bike, but it has one shortcoming: The fuel range is very limited. I can only get 110 miles from a tank of gas before I have to go on Reserve. This isn’t a fuel-economy problem for me; it’s a gas-tank problem. Is there any way to increase the fuel capacity? Can I purchase an aftermarket tank? Does the tank from a 750 Shadow have more capacity, and if so, would it fit my bike?

Pvt. William Barnebee, USMC

Anacortes, Washington

If what you ’re asking is whether there are larger gas tanks available that would bolt right onto your VT500C, the answer is no. If what you re asking is whether there is some way to put a larger tank on your VT, the answer is yes. Just understand that the solution is likely to cost more than a few bucks.

You could buy a used fuel tank from > something like a 750 Shadow (just be aware that on early 750 Shadows, the teardrop-shaped housing between the handlebar and the seat is a fake gas tank and that the real gas tank is under the seat) and try to adapt it, but that would involve some welding and repainting.

If you ’re going to go to all that expense, why not just take your stock gas tank to a custom-bike builder or reputable sheet-metal fabricator in your area and have them modify it. A good sheet-metal shop could widen the tank to gain an additional gallon or so of capacity, and you would keep the original tank’s basic shape and style. It might cost several hundred dollars to have all of this work done, but if you like your VT500C as much as you say you do, the expense may be worthwhile.

Power, to a degree

I have been told that degreeing the camshafts on my Honda CBR900RR would give me maybe 5 horsepower more. Exactly what is involved with degreeing the cams on a 900RR, and is it something a reasonably competent home mechanic could do? Also, would replacing the stock clutch springs in my RR with “heavy-duty” springs result in more rear-wheel horsepower? Allen While

Allen White

Austin, Texas

Degreeing the cams may give your 900 more power, maybe not; it all depends upon how close your particular engine matched the ideal cam-timing specs when it was assembled at the factory. There are minute differences from one cam to another, from one cam gear to another, from one valve to another, even in the location of the cam-bearing saddles in the cylinder head between one head and another. Degreeing the cams determines just how close a random selection of these components came to equalling the factory specifications when they were all assembled, and allows you to adjust the timing if needed. I’ve seen instances when cam-degreeing netted more than 5 horsepower, and others that netted virtually no gains at all.

This definitely is not something a home mechanic should do. Especially-and I say this with all due respect to you, Allen-a home mechanic who suspects that stiffer clutch springs will yield more horsepower. E3