Motorcycle – Page 73 – Not Your Average Engineer

March 25, 2010July 1, 2020

Replacing the fork seals on a PC800

NEWER NOTE: A member of the IPCRC re-wrote Fred’s instructions and consolidated them into one place. They are here for your reading pleasure.

NOTE: Of particular interest to people who are rebuilding their forks are the following posts/threads by Fred on IPCRC. Thread #1 Thread #2 Thread #3 Thread #4. The biggest things are 1) don’t be afraid and 2) go slow and take it slow. Also feel free to ask questions here or, better yet, on the IPCRC.

About a month ago my PC800 started bleeding fork oil down the right side of the bike. A quick inspection pointed to a blown fork seal on the right fork. This was a surprise as the previous owner who is a friend of mine had only replaced the seals 5000 miles previous. Off I dutifully went to the internet to buy some Honda OEM seals and dust boots. They arrived and I got down to the business of taking apart the forks.

Fork oil bleeding all over the wheel cover. The road grit and grime really sticks to it.

Lots of grit and grime around the top of the fork travel.

To remove the forks I only had to take off the wheel plastics, wheel, and the two small covers by the handlebars. The fairing stayed on. Some people on IPCRC do it this way and are satisfied. Others believe that the fairing should come off so a proper tightening job can be done upon re-installation.

I tried to find a good set of fork gaiters to put on when I reassembled the forks. However the pair I bought off the internet were woefully undersized. Check this thread on IPCRC for more information. Other people on IPCRC have had luck with finding good gaiters but I didn’t.

Once the parts arrived I started disassembling my forks. My living room quickly turned into something from the Dexter TV series. Instead of murdering people, I was disemboweling my forks.

When I took apart my forks I discovered an odd set of springs inside. No one on the IPCRC was able to identify them. Some suggested I replace them with Progressive springs. I chose not to because they had been in the bike at least since the previous owner had done the fork seals 5000 miles before. He found them in there and put them back, too. This is the third set of forks on a Honda in my general area that I’ve seen with this fork configuration. Each bike was different so I know it’s not some localized dealer thing for one particular model. Probably at some point in the 90’s someone was selling a spring kit locally. The way the two springs are setup, it makes a defacto set of Progressive springs. However, they aren’t quite as nice as real progressives. Oh well. They work well enough and I didn’t have to spend a bunch of money and wait for new springs to come.

During the installation process I did something REALLY stupid. I put the fork bushing in before I put the slider rod in. This trapped the busing in the fork. Much running around town to all of the auto parts stores and the Honda motorcycle dealer came to nothing. I scratched up the bushing pretty bad trying to get it out with a pick. Right away I ordered a new set of bushings. Of course it took two weeks to get to me so during that time I tried several other methods of extraction. The only thing that I could get to work (and I tried a LOT of different approaches) was a braising torch. I heated up the aluminum fork housing around the bushing until a little gentle taping on the ground got the bushing to fall right out. I was VERY careful with the way I heated up the aluminum to make sure I didn’t weaken anything by heat treating it or in some other way changing the material properties.

Another problem I ran into was with the rebound springs. For some reason they were really stuck in the bottom of the fork housing. I couldn’t see them in there and was pretty worried that I had a fork without any. Finally after much hand wringing I discovered them by accident. I don’t know how the IPCRC puts up with my stupidity sometimes 🙂

Once I had the new bushings, everything popped back together easily. I chose to use 15 weight fork oil since I’m a big guy. It made the bike handle much more like a sport bike but it also has made the ride somewhat rougher. With a passenger or carrying camping gear the bike goes back to super plush and feeling like a tourer. Next time I might bump down to a 10 weight fork oil although I really do enjoy the cornering performance with this 15 weight. YMMV due to my wonky spring combination.

It was a little difficult getting the top caps put back on but they finally went into place. Reinstalling was a bit of a challenge but I’m pretty confident that I have the bolts holding the forks to the motorcycle well-tightened. 2000 miles later and they show absolutely NO sign of sliding up the triple T. The new seals seem to be holding well so far. Fingers crossed that I don’t have another one blow out. The fork tubes have some pits in them though (nothing you can really do about it once they’re there but fork gaiters will protect against new ones) so I think this might become a routine 10-20k mile sort of project.

As I was reassembling the front wheel I found that my wheel was sticking and not turning very easily. I ended up having to reassemble everything to get the wheel to spin correctly again. On my wheel anyway it doesn’t spin completely freely when the speedometer cable is attached. Perhaps I should lube mine soon…

March 24, 2010July 1, 2020

Looking for oil leaks

I’m back on the hunt for this mysterious oil leak. While I do think that I have a bad oil seal on the slave clutch cylinder, I suspect that I might also be leaking oil from the gear shift lever and the neutral indicator wire pass-through. There also could be oil sneaking down from somewhere further up the engine but I’m not convinced one way or the other on that point. The photos below are what I found when I took the plastics off my bike earlier today. Please feel free to chime in if you have any thoughts on what I should be replacing or repairing to stop the oil bleeding.

Once again I am working outside my apartment. The tupperwear came off MUCH easier this time than the first time I had to figure out how to take it off.

Oil oil everywhere! It looks like the oil is either coming from further up the engine or is being blown around a bunch from the wind while I ride. The only things I can think of above are the wire for the neutral sensor, large gaskets on the engine that I really don’t want to mess with, and that’s about it. The cam plugs (see below) are solidly sealed now.

There was oil pooled in a little drip below the gear shifter hole. I wonder if that seal is bad or if it is getting blown there from somewhere else. Oil drips were also pooled on the bottom of the water pump. I replaced the water pump seals back in December when I did the cam plug job.

Under the bike looking from the front rearward. The oil leak is on the right side of this photo. The oil stain in the rear left side is from where I spilled some oil doing a field oil fill-up after having problems in the redwoods of Northern California last weekend.

Looking back toward where the oil gets blown. It’s interesting that there really isn’t any oil residue beyond where the kick stand attaches to the spring. The center stand doesn’t have any oil on it nor do any of the components back by the rear tire.

That little screw I found wedged between the drain lines coming down from the carbs and the gas cap area to where they empty out under the bike. As the note says (so I wouldn’t forget while doing other things), that screw is one of two that hold the throttle cables to the carbs. It was VERY lucky that this little screw didn’t fall off the bike but instead migrated to somewhere I was able to find it. And it was even more lucky that I right away figured out where it belonged. Back in December when I did the cam plug job, I took off the throttle cables. Evidently my tightening down that screw wasn’t enough to keep it in place. I put it back in with a little dab of blue loctite. It should stay put for a long time to come.

I’m pointing to where that screw belongs. It didn’t affect the performance of the bike noticeably but eventually if it had been left like that, I think the throttle cables would have worn through faster.

When I put the bike back together after the cam plug job, I didn’t bother re-securing the rubber boot that attaches to the fiberglass (?) engine cover and protects the carbs. It still seems to do its job just fine but now it’s much easier for me to look in at the engine and figure out if the cam plugs are leaking. So far all four look just fine!

Any thoughts anyone might have on what seals I should replace would be much appreciated. Thanks for looking!

March 23, 2010July 1, 2020

1280 miles in 36 hours with an oil leak

Between Saturday and Sunday I went on a wild ride from Corvallis down the Pacific Coast and Redwood Highways to Point Reyes Station and back up I-5 to Corvallis. The total distance was 1280 miles give or take. I did the whole thing in 36 hours with 11 of those hours being used for rest in Point Reyes Station.

Originally I had planned to go over the Cascades and slip down the east side into Nevada and eventually to Death Valley. However, due to pass conditions and an inclination to go along the coast, I went down the 101 toward San Francisco. It’s a good thing I did because otherwise I’d be in the middle of Nevada with a bad oil leak right now.

At around Klamath, California I suddenly lost power going up a hill. Pulling over and putting the bike up on its center stand, I found that an itty bitty oil leak on my left crank case had become a much larger leak. It took about a quart of oil to bring my bike back up to full. After that I was off and down the road again.

Driving through the redwoods at night on the freeway south of Eureka, California was an amazing experience. There wasn’t one piece of straight road for probably 40 miles. The two lanes of southbound tarmac were wide-open, beautifully marked with reflectors, and perfectly banked for 65 MPH travel. I only saw a couple other cars on that entire stretch of road. It felt like I was playing some retro-futuristic video game. It was so, so awesome!

Getting gas in Ukiah, the gas station worker challenged me to an arm wrestling match. She was in her 60’s. In the end she relented and gave me my change.

In Petaluma I got lost and ended up driving in the wrong direction. I had a lovely tour of the salt marshes between Petaluma and Napa though. Finally I figured out which way was west and rode into Point Reyes Station at 330am. It had been a long day of driving.

The next day I got out of Point Reyes Station late in the day and headed off to I-80 and then to I-5. Somehow I missed a turn and had to go through Sacramento. It was a good thing I did though because when I got to Redding, California, the guy at the pump behind me turned out to be a fellow PC800 owner. He had tailed me on the freeway for 50 miles in his car waiting for me to pull over for gas so he could say hi. It sounds like I might be going back to Redding soon to trade Art my windshield for his windshield.

Going over the pass on I-5 I was reminded how much the roads in Oregon suck at night. It took quite a bit of concentration to stay on the road and in between the lanes. I often tailed semi trucks to follow their brake lights. Maybe someday Oregon will get with the program and put reflectors on the roads.

I rolled back into Corvallis at 1am. The tip of my right thumb is still numb, my right hand is physically weak from using the clutch so much, and my right foot is numb on top. I also lost seven pounds during that ride. I stayed hydrated the entire time with a 100 ounce Camelback water bladder tucked in my backpack. Who knew motorcycling was so demanding?

The parts to fix my bike are on order and should be here in a week or two. The job will probably take about six hours to complete. I can ride the motorcycle until then but I will be keeping it within 100 miles of friendly garages where I can park it until I can go and fix it wherever that garage happens to be. My AAA towing plan covers up to 100 miles. 🙂

I stopped for gas many different times during the trip. The gas stops are listed below:

Waldport, OR: 139.1 miles, 3.027 gallons, 45.95 mpg (This also included the ride from Waldport to Corvallis and up Marys Peak from the day before)

Port Orford, OR: 136.6, 2.854 gallons, 47.86 mpg (Lots of wind down the coast)

Klamath, CA: 109.3, 2.352 gallons, 46.47 mpg (I was fighting some nasty winds coming down along the 101 in Oregon)

Miranda, CA: 120.2 miles, 2.687 gallons, 44.73 mpg (Too much fun on the freeway through the redwoods!)

Unika, CA: 100.2 miles, 2.105 gallons, 47.60 mpg

Point Reyes Station, CA: 137.4 miles, 2.993 gallons, 45.90 mpg

Arbuckle, CA: 140.1 miles, 2.973 gallons, 47.12 mpg (not bad for doing 75 on the freeway for most of the previous tank)

Redding, CA: 109.1 miles, 2.673 gallons, 40.8 mpg (I was doing 75 on the freeway on the whole tank to Redding. I also had a small over-fill of a few ounces.)

Yreka, CA: 95.0 miles, 2.406 gallons, 39.48 mpg (I was pulling up the hills at 65 mph or faster out from Redding)

Grants Pass, OR: 81.3 miles, 1.816 gallons, 44.76 mpg (I went over the pass and was going slow most of the way due to poor road markings)

Cottage Grove, OR: 115.9 miles, 2.492 gallons, 46.5 mpg

Along the Pacific Coast on my Pacific Coast

It was pretty windy through this section. A storm was rolling in.

My motorcycle with before I put the gear back on

My bike has some brake dust coming off of it. Looks like I'll be due for some new brakes soon.

Sondy went on a short ride with me before I headed out of town.

My Route Map