Service
Service
RAY NIERLICH
GEARING FIX MISSING SPARK BJS(E -> WASTED MOTOGP SOUND
Looking for more relaxed cruising on the highway? Generally, it's better to go up a tooth on the drive sprocket than to go down a tooth or two in back.
SMALLER OR TALLER?
Q: I'm interested in the Honda CBR300R and, if I buy one, would probably want to change the final gearing by replacing the rear sprocket with a somewhat smaller one. Having ridden (and learned from) an Italian 25OCC single in the ’60s, I’d be glad to exchange some acceleration for a more relaxed and smoother ride at higher speeds. Are there any rule-ofthumb suggestions for such a swap?
HUCH TURNBULL CYCLEWORLD.COM
AB Always front sprocket start by size increasing if possible. the Larger sprockets mean less angular acceleration and thus a longer, happier life for the chain. Smaller sprockets may require shortening the chain and may also cause increased wear on the swingarm pads. Stock CBR300RS come with a 14-tooth front and 36-tooth rear sprocket, giving a 2.57:1 ratio. Go up one tooth in front and you will get a 2:40 ratio, giving you a 7-percent reduction in engine rpm at a given speed, and you can use the stock chain without alteration. Try this before reducing the rear sprocket size. Aftermarket 15-tooth front sprockets are available, affordable, and simple to fit.
PHYSICS IS PHYSICS
QB What motorcycle is the engines? best oil for Chinese
B MWANCIISAAV
CYCLEWORLD.COM
AB whether The laws an of physics engine originates remain valid B from China or elsewhere.
The current state of Chinese engine development is comparable to what was typically available worldwide in the ’60s or ’70s. More modern production techniques are employed now of course, but the finished products are generally saddled with low specs by modern standards, occasionally suspect materials and tolerances, and irregular inspection procedures. I’d go with an oil that’s at least comparable to what was used 40 years ago. It might also be wise to use a heavier grade than
recommended for modern engines, say a iow-40 or a 20W-50. As always, if your engine has a wet clutch, be sure to use motorcycle oil and not current automotive oil with friction reducers that can wreak havoc. I fail to see any worthwhile advantage in using a synthetic oil. Save that dough for your next motorcycle.
FINDING THAT LOST SPARK
QB While Suzuki in RG125 Italy, with I found 5,000 a 1992 * kilometers on the odometer.
We removed the motor and we were able to bring the bike back to the US.
My mechanic put it back together and started it. The RG runs perfect, but after about 30 seconds it stops running and loses spark. To start it again, we have to wait 10 to 15 minutes. We tried to change the stator with an NOS one I located in the UK, but the problem persisted. Your help is appreciated.
ROBERTO PETTINATO CYCLEWORLD.COM
AB what The problem you think probably it is. With isn’t only 3,000 miles and 22 years elapsed, this bike obviously has been sitting a long time. It may well have crankcase sealing issues and corrosion problems, so check that first. The capacitor-discharge ignition or CDI, as on this bike, either works or it doesn’t, with no in between. Lock yourself in the darkest room on the darkest night of the year, and look for that spark again. CD ignitions have a short-duration spark that doesn’t look like other high-tension sparks. Check all ground connections to make sure they are clean and tight. Consider running extra, dedicated ground wires from coil to engine and engine to battery. A battery is required in the circuit to properly fire the CDI. Battery eliminators don’t count.
BEARINGS IN MIND
I own a very-well-cared-for 1984 Yamaha FJ1100, which just * crossed the 40,000-mile mark. While having the local Yamaha dealer mount a new front tire, I also supplied
GOT A MECHANICAL OR TECHNICAL PROBLEM with your beloved ride? Perhaps we can help. Contact us at cwservice@cycleworld.com with your questions. We cannot guarantee a reply to every inquiry.
a new set of wheel bearings and oil seals to be installed. There was nothing wrong with the old wheel bearings;
I just decided that retirement was in order after 30 years of service. My issue: With the bike on the centerstand and the front tire off the ground, the wheel would spin freely with the old bearings and would take a long time to
stop spinning. With the new bearings, there is a great deal of resistance. I’ve ridden the bike around town three or four times, maybe 5 miles each trip, in hopes that the new bearings would get “broken in.” However, the same resistance is present when I rotate the tire by hand. The front brakes are not binding in any way. Touching the rim
along the axle near the location of the bearings after riding doesn’t indicate any heat buildup (which I suppose you would feel if the bearings were in some way failing). My question: Do new bearings require a break-in or loosen over time?
TIM HOWARD CYCLEWORLD.COM
A Ball bearings, as used in 99 percent of motorcycle wheels, H don’t have any break-in. After some normal use they will seem to loosen slightly. This looser feel is due to the grease that was originally packed inside channeling around the races, reducing drag on the balls and cages, and the seal lips wearing slightly, also reducing drag. This was the situation when you spun your wheel with the old bearings in it. With new bearings, it should spin by hand easily but not continue spinning for more than a revolution or two.
If you aren’t confident in the new bearings, as seems the case, go back to your dealer immediately and have them take another look. I would pull the wheel and inspect to be absolutely sure the required spacers and the speedometer drive are installed correctly. If side thrust is being applied to the bearings from mis-assembly, some very bad things will result.
STOP STANDING UP
QB and I own am a 2007 pretty Yamaha satisfied FJR1300 with it,
* except for the tendency for it to “stand up” while leaned over through a curve. I’ve been riding for many years and have had many bikes, but I don’t recall any that made me feel as uneasy while going around curves as I do on my FJR. It takes quite a bit of effort to keep the bike leaned over. I’m no expert when it comes to bike setup; I’ve been lucky to have most of my previous bikes set up just fine for me from the factory. So far I’ve tried three brands of tires on the FJR (factory Metzeler, Bridgestone BT-023, Dunlop Roadsmart II), but all have felt pretty much the same. Do you have any suggestions for what I might try to make my bike feel more neutral while leaned over? Someone suggested that I try a 60-series front tire instead of the 70-series.
RICK ¡ONES HUNTINGTON BEACH, CA
A As the fabulous FJR1300 a is, barnburner it is a relatively as B tall, relatively high eg, nearly 700-pound motorbike. It does require a fair bit of countersteering on the handlebars to keep her heeled over. In addition, spring rates and damping at both ends are on the low end of the spectrum, allowing for too much dive and perhaps some bottoming with heavier loads.
Our resident expert in this matter is Paul Dean, who has as much seat time on a FJR1300 as the rest of the staff put together. Paul says front-tire choice is important. The Michelin Pilot Road 3 was easily the best front tire he tried on this bike, but he has no experience with the newer Road 4, so you’re on your own there. It would never occur to either of us to try a 60-series front tire. The other worthwhile improvement is to increase the front spring rate and alter the damping to suit. If funds allow, continue with equivalent shock upgrades. ETU
