Tech Questions & Answers

Got a question? Try to stump Mark at zimmemr@aol.com

Retiring
I have a 2006 H-D Electra Glide Standard, with 10,500 miles on the original Dunlop tires. In the spring, I expect to replace them. What is the typical mileage I can expect from any tire? The owner's manual says to only use H-D tires. If I replace with the same size tires I am sure I'll be safe, so when the owner's manual says to use only H-D tires, are they doing so to promote sales or is there a safety issue?
John
Milford, Ma

It's hard--in fact, impossible-to determine what the average tire's life span is. There are just too many factors to take into consideration, but 10K isn't bad under any circumstances.

As to OEM tire recommendations, manufacturers do an enormous amount of testing to ensure that the tires they spec are compatible with their motorcycles. Are the ones they recommend the best possible choice? Maybe and maybe not, but you'll seldom go wrong by using them. By the same token, if a reputable tire manufacturer says their tire meets all the OEM tire specification criteria and is safe to use on a given bike than you can reasonably assume that it is. However if you're using a non-OEM recommended tire I'd advise you stick with a name brand and use only the tire that they recommend for your application.

Thunder from down under
I have a mechanically stock 2008 H-D XL883C. I intend to keep this bike for some time. As a result, I am planning some basic performance upgrades so I will remain happy with her in the years to come. This is what I am planning: an 883-1200cc conversion, a SE Stage 1 air cleaner, Screaming Eagle Super tuner, and Screaming Eagle performance slip-on mufflers.

With the 1200 conversion, there seems to be two basic ways to go. Keep the 883 heads (using reverse dome pistons for compression and valve clearance), or go with 1200 heads. The catalogue has options for both. One is a Stage 1 "kit" which has everything including 1200 heads, air cleaner and a clutch spring.

What are the pros and cons of keeping the stock 883 heads over using 1200 heads? Some say the freer-flowing 1200 heads will perform better, and some say the 883 heads will give you more torque. Either way, I haven't heard anything negative about using the 883 heads, and the cost saving is worth thinking about. What do you think? Also, how does the above set-up sound to you overall? I'm just after a general all-round improvement in performance. I do a lot of open road riding, so I don't want to compromise my cruising capability.
Mark from OZ
via e-mail

If I were building a hot rod 883 I'd pretty much do it the way you're planning. 1200 cylinders, 883 heads (with maybe just a clean-up to the ports, depended on how ambitious I felt that day), a Screaming Eagle pipe, module and air filter, and without a doubt a heavy-duty clutch kit. I'd also use a two-into-one exhaust system, as I think they offer better all-around performance, but not everyone feels that way, or likes the way they look.

As to the heads, I prefer stock or mildly ported 883 heads. The smaller ports enhance flow at moderate rpm increasing low and midrange power and don't really hurt the top end. 1200 heads with their larger ports and the corresponding reduction in intake velocity make the engine feel lazy off the bottom and only come into their own at high rpm; even then, it's not a significant improvement.

A good friend of mine, built a dirt tracker a few years back using the above formula, with mostly warranty and crashed- bike parts. It wasn't the fastest bike in the class, but it was capable of the occasional win. It was also the only bike that started on the button, idled and could be ridden to the concession stand for lunch.

VIN-dicate
Just received the 2010 Buyer's Guide. Great issue! I have one little problem that you may be able to help me with. At a recent trip to my local cycle shop, I noticed a sign (hand written) that said '2010 Yamaha 1300'. Keep in mind that the only difference between the 2010 and the 2009 is the handlebar, so how am I supposed to know if it is indeed a 2010 or a 2009 or a 2008 for that matter? Sure the sign says 'New and improved, tastes better and is chock full of nine essential vitamins', but is there something in the serial number that will tell me for sure, and is it the same for all cycles?
Ron Rickers

Elk River, MN

The 10th character of the VIN number represents the model year of the vehicle, so 9 would stand for 2009, "A" will be used for 2010. Yes, that rule applies to motorcycles, cars, trucks and even heavy equipment, so long as the DOT 17 digit VIN code is present.

Secondly, there is always a build date tag on the bike; typically, these are on the steering head, and while it's by no means a hard and fast rule, for most manufacturers the build date for 2010 starts in August 2009, so anything built between August 2009 and July 2010 will be a 2010 model year bike.

Lastly, the title and the MSO (manufacturers statement of origin) have the model year stamped on them, and there are huge penalties for anyone caught fudging them.

2010 Star VSTAR 1300