With new tires,and the maintenance and repairs 99% complete it was time to give the bike a longer test run to discover any remaining issues, and to start breaking in the tires.
The 70 mile trip primarily consisted of the following:
Rush hour traffic (stopped for about 10 minutes trying to get onto a highway) on the way out
40-50 MPH twisty back roads on the way out
60 and 70 MPH Freeway driving on the way back.
Some 25-35 MPH city driving on both ends
The bike did great! The only problem that I encountered was a lack of lubrication in the speedometer and tachometer cables. The tach, especially, was bouncing around above 5000 RPM.
While I was idling in stopped traffic the bike did slowly warm almost to the top of the normal range, but it never overheated. If I were to do much of this kind of riding I think I’d upgrade to an electric fan. When the bike was moving the temp gauge pretty much stayed at the transition between the thin and wide white bars. In other words, right where it should be.
Curious about fuel economy I fueled up near the start of this trip, and again at the end. I burned about 1.3 gallons over 67 miles, or 51 MPG. Not bad!
Installed and Balanced New Front/Rear Tires: Shinko 712’s
Front: 100/90H-19, Inflated to 28 psi
Rear: 130/90H-16, Inflated to 36 psi
Replaced Brake Stopper Arm Cotter pin
Adjusted rear brake
Replaced Grips: ProGrip 714’s
Today the bike got new tires, Shinko 712’s. The Shinko’s, while inexpensive, come highly rated. Shinko bought the motorcycle tire division from Yokohama.
Changing tires is a pain. I’d like to think that it’s because the tires are old and stiff — not me. On the rear I managed to get one side off, but for the other side I finally ended up cutting part of the outer tire away with a Sawzall so that I could get at the bead wires with a bolt cutter.
I used the “2×4 method” to break the tires. That was easy. For my pivot point I just C-clamped a 2′ length of 2×4 to a 4×6 post supporting my deck.
After getting the new tires on, which wasn’t too bad, I couldn’t get the front tire bead to seal and seat. Nothing worked. I tried removing the stem core, a shorter air hose, a strap around the tire, thicker soap, bouncing the tire, zip ties and various combinations of the above.
Unwilling to use explosives to seat a motorcycle tire, I took the wheel to a custom tire shop. The shop’s larger air compressor didn’t work either, but they had a “Cheatah”, or bead seater. You can buy these things for $50 on eBay, delivered. You can also build one using a propane, or similar tank. All they are is a 5-gallon air tank with a 1.5-2″ valve and pipe. You fill the tank and then quickly open the valve while filling the tire with air. Fast and easy. It’s too bad I couldn’t justify buying one of these, it turns out they can also be turned into potato guns. The tire shop only charged me $10.
After balancing the tires, I installed them on the bike. I discovered that Shinko rear is a bit wider than the Metzler it replaces. I know this because I had to deflate the tire to get it past the final drive. I didn’t have to do that with the Metzler.
Balancing the rear tire
Before mounting the tires I put the wheels on the balancer to find and mark the rim’s heavy spot. Unfortunately, after mounting the tire on the front wheel I discovered a stick-on weight that I had missed; I had removed the spline weights. Not wanting to remove the tire, I removed the errant weight and just aligned the tire’s light mark with the stem, the way they do at the dealer.
On the rear, the heavy side was almost on the opposite side of the tire from the stem, so that’s where I aligned the tire’s light mark. The front wheel took 20 grams to balance, 15 grams for the rear. If I had aligned the mark on the tire with the rear stem, it would have taken a lot more weight to balance.
I couldn’t re-use the weights that clip over the wheel spline — too heavy. At some point, for aesthetics, I may replace the silver weights I installed with black ones. All I had were silver.
When I ordered the tires, I also ordered new grips for $10. The grips that were on the bike were ProGrip 714’s. I like these gel grips, but the left one was damaged on the end. I used compressed air to blow the old grips off, and again to blow the new grips on, though I guess I’m technically pushing them on as the air is trying to blow them off. Very fast and easy, no soap, alcohol or hairspray.
Zinc plate straps, strap screws, and cable bracket
Zinc plated seat bolts, washers and spacers
Replace accelerator pump
Replace bowl gaskets
Lubricated choke and throttle cables
Adjusted idle mixture
Adjusted idle speed
Slightly repositioned master brake cylinder to be more upright
When I first got the bike it wasn’t running. The problem was clogged jets. As I didn’t have rebuild kits at the time, I just cleaned out the jets and bowls and put the bike back together.
With rebuild kits in hand I removed the carbs again. This time I separated the carbs so that I could get to all of the parts and give the carbs a more thorough inspection and cleaning.
I didn’t have replacement throttle plate screws, and wasn’t even sure the kit contained throttle-shaft seals, so I left those alone. The thottle shafts seem pretty tight fitting. The choke shafts had a fair amount of play in them, but air getting in past the choke shafts shouldn’t affect mixture.
One of the air cut-off valves was missing a very small seal. This is another part that wasn’t in the kit. However, as it turns out, the very small o-ring seal is the same diameter as the seal and washer that goes around the idle mixture screw, but much thicker. I had extra idle mixture screw seals, but they weren’t thick enough for a good seal. To get around the problem I used an idle mixture screw washer under the seal to push it up high enough that the cover would seal against it. The cut-off valves were in great shape.
Note for future reference: The air cut-off valve with the hacked seal is the one that’s accessible on the left side of the bike. If a proper seal can be obtained, it can be installed without removing anything from the bike.
The previous owner told me that the carbs had been rebuilt three years ago. That seems to be the case as I ended up not replacing anything except the bowl seals, and one of the floats which I accidentally broke. Unfortunately, the kits didn’t include new rubber plugs. As you can see in these pictures, the rubber isn’t in good condition. Those parts aren’t available from Honda, but I think there are after market parts on eBay. They should be replaced because bits could fall off and clog a jet.
The new accelerator pump is on the bowl on the left in this picture. The new bowl seals are also in place.The carbs are ready to go back in the bike. Here you can see the re-plated front strap and cable bracket. While I had everything apart I gave the tops a quick polish as well. It’s too bad you can’t see much of the carbs when they’re on the bike. They look pretty good!After lubricating the cables, the throttle was still sticky. It turns out that I had routed the cables under the frame rather than over, as shown in this picture, which was taken right after I bought the bike. I removed the carbs — again — and routed the cables over the frame. Works great now. It’s psychological, I know, but with less friction in the throttle cables the bike feels quicker. Who knows, with cleaner carbs the bike might have a bit more power.
Throttle and choke cables route over the frame (the bike was pretty dirty when I bought it!)
After installing the carburetors I warmed the bike up and started dialing in the mixture. I used the RPM drop method to get close and then tweaked a bit until the idle was smooth, and had good throttle response.
The bike is running really good now, at least at in-town speeds. After I borrow, or make a tool to balance the carbs, I’ll do that and re-tweak the idle mixture.
While working on the throttle cables, I decided that the master cylinder should be more upright. So I repositioned it, and added more DOT4 fluid.
The two straps that hold the carbs together on this old bike had some corrosion on them. Since I managed to drop and break one of the floats while rebuilding the carbs, I had some time to consider plating those parts while I wait for the replacement float to arrive. After researching DIY zinc plating I decided it didn’t look that hard. It wasn’t!
I’m so pleased with the results that I’m now looking around and asking “What else can I plate?”.
On the carbs I plated the front and rear straps, and the cable clamp bracket.
I’ve created a separate page that describes how to do this.
This was cleaned and polished less than a month ago. The rust has already returned.Zinc Plated and Polished. I don’t expect it to rust again for a long time
When I adjusted the valves a week or two ago I replaced the large outer valve cover gasket. Unfortunately I had neglected to purchase the smaller gasket that goes around the spark plug well. I reinstalled the old center gaskets and ended up with an oil leak that stopped after a couple of short rides.
The leak was a little puzzling at first because there didn’t seem to be any oil on the new valve cover gasket. That’s because the oil was leaking into the spark plug well when the engine was running and coming out a drain hole on the lower side of the cylinder case.
While pondering the leak I realized two things. One, the new gasket would be thicker and so the old, center gasket might not have as much pressure applied. Two, that the “rubber, settings” as they’re called in the parts fiche, were probably a bit flat too. These are the rubber seals that fit around the valve cover bolts and apply downward pressure to the cover. So new rubber was ordered and installed.
Below is a picture of a valve cover bolt with what I’ll call the hold-down seal. You can see how compressed the old rubber on the right is relative to the new rubber the left. I cut the old rubber off with a knife after separating the rubber part from the cap. The new parts have beveled rubber on the cap side and push on over the bolt’s shoulder without too much effort. With the new parts installed I could definitely tell there was a lot more pressure on the valve cover as I tightened the bolts down to the metal stops. Shouldn’t leak now.
As an aside, these parts are shared with Goldwings, so while I installed Honda OEM parts, there are non-OEM versions of this part available as well. In fact while four of these are used on the GL500, eight are used on Goldwings, so I found a lot of 8-packs available on eBay when I was searching for parts.
The task I’ve been dreading is done. The fuel tank is now clean.
There are many techniques for cleaning tanks: toilet bowel cleaner (hydrochloric acid), phosphoric acid, oxalic acid, vinegar and even coke or molasseses. You can also use electrolysis, or throw the tank filled with sharp objects into a sleeping bag and then into the dryer. I chose to use oxalic acid because, like phosphoric acid, it leaves a coating which helps prevent rust. I would have used phosphoric acid, but I already had some oxalic acid available. Oxalic acid also doesn’t affect the paint.
I started the task by shaking the tank with some kerosene and a length of swing-set chain inside. The kerosene came out brown, so I did some good with that. I wasn’t expecting this to clean the tank, I just wanted to knock of any big stuff first.
After the kerosene I degreased the tank with Dawn detergent and water.
Next came the oxalic acid. I used two cups of powder in 4.6 gallons of hot water. The tank was pretty clean after six hours of soaking, but I decided to let it go overnight, so twenty hours total. I then flushed the tank several times with water, then water with baking soda to neutralize any remaining acid, then more water.
The last step before filling with gasoline was to slosh around about one-half gallon of denatured alcohol to get any last moisture out of the tank.
The red stuff you see around the filler neck in the before picture is what’s left of an old tank coating. I cleaned that off with acetone and a cotton swab. There’s still a bit in the bottom of the tank which I didn’t try to remove.
I discovered why the red coating was in the tank. You can see where the red coating has sealed some small perforations on the front, lower-left corner of the tank. This picture was taken several hours after I cleaned the tank and filled it with gas. It doesn’t appear to be leaking, but I’ll be keeping an eye on it.
Upon inspection the petcock bowel screen and gasket didn’t look that good, especially the gasket as you can see in the picture below. You can’t buy the filter any more, so I ordered what looked to be a whole new petcock off eBay for $8 with shipping. I could use it, it fits, but as you can see the new petcock on the left has shorter pickup tubes, so less reserve capacity.
The new part doesn’t have a bowel filter, so I decided to steal the gasket from the new petcock and reinstall the old petcock. I’ll try and find a gasket so I can have the new one as a backup. Unfortunately the pickup tubes are not interchangeable.
Last task for today was to change the front brake fluid. I ran a lot of DOT4 fluid through the system to flush it. The old fluid looked clean, but it was slightly darker in color than the new, so it was time. The master cylinder was, and is, in very good condition. Brake feels good.
