Service

SERVICE

Deep-fried Hondas

JOE MINTON

I have 1979 and 1981 Honda CBX Sixes. I'd like to get as long a life as possible out of these bikes, but I'm concerned about them running too hot. especially down here in Texas. I've heard CBXs are famous for running hot.

Could you tell me what the proper oil and cylinder-head temperatures are for maximum engine life? What should I be concerned with more, the oil or the head temps?

Kenny Smith Meadows, Texas

Cylinder-head temperatures vary w idely, but most air-cooled four-stroke engines will run betw een 280 and 380 degrees at the base of the sparkplug.

Oil temperature is more critical. Oil should reach at least 180 degrees (in the sump or an oil gallery) to get rid of the water that naturally accumulates (it is the main by-product of combus-

1/oil). \/avii;lunl oil lift' `iII he reac/u'(/ i/ 1/ic' oil (loes /10/ ex(ec'(/ 2 / 0 (l('~i'('~'.S. /1/? I risc' /11 0/)CraIiiU~' IC/li/)C/i11lIi(' (ih()l't' I/ia! will s/lorlc'n its life (1/1(1 reduce i/S (11)/li/I' 10 protect 1/IC eiiginc'. liii a.c a /)raclical ,,ialler. you

(10 1101 1lC't'(l 10 be over/v (oiuerne(1 (thou! oil iei~i~~eraiures he/mi ahoui _)_/() degrees. :l/'o~ 1/la! leniperalure. 1/wag/i. oil itill (IcIer/orate a! a i~' ni/kant rale.

I iL'(Olflh?lt'!l(l (/1(11 i)11 iii.sitill an oil> tei;iperaIure gauge (I use I `I)Os,~ in 1/Ic' oil gal/err /eecling 1/Ic' ranks/ia/i. 1/ normal ru/liming leniperalures slav below 240. don l worn' aboui it.

Jetted Sportster

I really liked your article “From Sportster to Speedster" (see Cycle World. June. I 991 ), but I have a few questions. When you swapped the stock handlebar with the I 983 XRlOOO’sand then removed I inch from each end. were the cables and wiring kept at their original lengths?

Also, if I were to add just the Screamin' Eagle air cleaner and the Bartels’ Performance exhaust system. would I still need the SI I 6 Dyno Jet carb kit. which seems overly expensive?

SSgt. John Tuttle Ramstein AEB, Germany

We used the stock cables and wiring with no problems. In fact, the clutch cable was able to be more neatly routed after the longer bar was installed.

Both the pipe and the air cleaner will alter the carburet ion. so carb work is required. / agree that the Dyno Jet kit is expensive. If you are mechanically inclined, try the following: Drill the air-bleed hole in the bottom of the slide (there are only two holes, one is for the needle) with a #3 / drill. Remove .0004-inch from the diameter of the straight part of the needle. This must be done very carefully, as the diameter of the needle in this area is very critical. It should measure . 1075inch in diameter when you are done. / use a piece of #600 sandpaper wrapped around a small flat file with the needle lightly chucked in a drill press.

Then remove the aluminum plug covering the mixture screw so you can adjust the idle mixture. l it a main jet (Bing jets work) two or three sizes larger than stock. That should put you in the ballpark, but as with all carb modifications, be prepared to experiment.

A forever Four

Based in large measure on the article “Keepers" in your April issue. I just bought a 1977 Honda CB750K—my first bike since the Norton Electra (yikes!) 1 rode in college nearly 25 years ago.

Your article recommended “brake improvements, electronic ignition and more powerful coils” as being desirable upgrades for this particular bike. Where can I get more specific information about these upgrades?

Many thanks for the initial inspiration. and for any help you can provide now that I've taken the plunge.

David Drucker Endicott, New' York

Your CB 750 's brakes can easily be improved by substituting Ferodo pads (Performance Research Organization,

/194 Shetland Way, El Dorado Hills. C'A 95650: 916/955-4166) for the stock pads, and by fitting a Teflon brake line from Russell Products (2645 G undry Ave., Signal Hill. C'A 90806: 215/595-7525 or 800/ 777/120). An excellent electronic ignition and coils are available from KV Products (810 /V. Cummings Rd.. Covina,

C 'A 91 724:818/ 96 7-3 786). There are other products that will do the job, but these particular companies have provided reliable parts and services for more than a decade.

Tingling Twin

I was a little surprised that the Yamaha 650 Twin was not mentioned in April’s “Keepers” story, especially since there are so many of these bikes out there, and the Yamaha 650 Society gets a lot of its information from your previous project-bike articles on the 650.

Brent Wride Kirkland. New Mexico

Perhaps / should have included the Yamaha 650 Twin: it was a close call.

/ didn't pick the 650 because it vibrates. I don't mind vibration very much, but a lot of riders do. Craig Vetter, of Windjammer fairing fame, used to keep an early 650 around as his rolling shaker table—if a new fairing design could survive the 650. it was ready for the public.

Certainly, the Yamaha 650 Twin is a fine motorcycle, especially the later models. It is reliable and long-lived, in spile of its tendency to excite seismic stations in its vicinity. I know that l certainly enjoyed mine.

The absence of anyone's favorite motorcycle on my "Keepers’’ list doesn't make the bike bad. Remember, the best motorcycle in the world is the one you own and ride. 28