VF-Series info

Cam problem description and oil mod options
Rear shock fluid replacement - VF series
Tire options
Replacement Fanstat

Cam problem description and oil mod options
by: Christopher Leach

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Rear shock fluid replacement - VF series
by: Joe Thorne - Forward by Christopher Leach

With the shocks in our bikes getting on in years, some folk have begun to experience significant sagging and less than desireable damping characteristics in their shocks. Unfortunately, Honda designed this shock as a 'non-rebuildable' shock. This means that the spring is sealed inside the shock and cannot be replaced. However, it is possible to get a few more miles out of them by improving the damping and increasing the air pressure (preload). The following procedure details replacing the shock oil with heavier fluid for improved dampening characeristics. (Editor)

I have never seen a rear shock leaking, but the service manual details how to change the seal. IMHO, if the seal is leaking, get a new shock. If you want to change the fluid, however, the manual still wants you to replace the seal. Ten years as a flat-rate tech, I sure as hell aren't changing a seal that isn't leaking.

Tools needed:
Whatever you need to pull the shock
Graduated beaker
Funnel small enough to screw on the airline for your shock

So the best and fastest way to replace the fluid is to remove the shock. (See your service manual). Once you pull the shock out, unscrew the Schrader valve from the hose. ( The valve screws on the line at the end, like a 10mm and 12mm hex heads.) Hold the shock at a 45 degree angle over the graduated beaker, with the valve and hose facing down. You will have to wiggle it back and forth a little to get all of the fluid out. The reason to drain into the beaker is this: My manual called for 300cc's of fluid, I got 340 out. I replaced the crap that came out, which was smoked atf, with atf. In hindsight, I would use 15wt fork oil. To replace the fluid, take your funnel and seal it to the air fill hose. I nailed the funnel to the workbench, and set the shock on the floor. However you do it, make sure the funnel is well supported as high as possible. I filled the funnel and walked away. Twelve hours later, I walked into the garage to see the last of the fluid drain out into the shock. I kept a small space heater on the shock to keep the fluid as thin as possible. (Editor's note: When I did this, I used 340 cc of 10WT fork oil. In retrospect, I too would use 15W for a little stiffer ride. Some listers have reported using 30W with no seal problems. Also, I used an irrigation syringe to force oil into the open hole in the shock body. Only took about 30 mins. The author's bike is a VF1000R, editor's bike is an '84 VF1000F Interceptor)

Tire options
By: Christopher Leach

I don't want to stir up any controversy about this tire is better than that one or whatever, I just wanted to make a few quick notes about tire options, specifically for the VF1000F/R series bikes. One of the best moves I made as far as tires was to mount radials on my VF1000F. The stock configuration is: 120/80-16 Bias Ply up front (I was running a Dunlop K591 SP-R compound. Developed serious cupping after ~4K miles), 140/80-17 Bias Ply rear (I was running a Bridgestone Battlax BT-17, wore well, still tread left after 4K miles.). In the radial arena, very few manufacturers produce tires in these sizes. I do know that Metzler makes the ME-Z2 in stock sizes for the bike. It should also be noted that a 150/70-17 rear may be mounted to the 3.5" rim w/ no clearance problems to gain a little more rubber. The 150/70-17 is also more widely supported by tire manufacturers. I have no data on fitting non-stock size tires on the front of these bikes.

Replacement Fanstat
By: Christopher Leach - Adapted form the SabMag FAQ

The stock fanstat (the Thermistor that shorts at a given temperature in order to activate the cooling fans) on the erly VF-series bikes waits a little too long before activating the fan for my taste. Honda sells a replacement fanstat which triggers at a lower temp, but for ~US$58 it's not cheap. If you would like the Honda part #, wander over to Robyn Lander's page (address in cam discussion area). However, a cheaper alternative is to order ECHLIN FS130, about $28 from NAPA. Turns on at 191-197F (ascending) and off at 182-187F (descending). The element is about 1/2" longer than the Honda one, but it screws right in and it has the two bayonet connectors found on early V4's.

Another option:

Brand name: GP Sorenson
Part Number: 40-5001
Price: $14.99 (Advance Auto Parts- prices may vary from state to state.)
Thread pitch: M16 X 1.5
Normally open
Closes at 189 to 199 degrees F
Opens at 181 to 171 degrees F
This switch is the direct equivalant to the NAPA #FS130
This switch fits many Honda car applications,
1975-1991 Honda Civic All 3 door(hatchback) and CRX models
also 1986-1991 Acura Integra, all engine sizes.

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