Dragging Front Brake?

Recently I’ve been having some troubles with the front brakes on my PC800.  The front wheel is not spinning nearly as freely as it should.  Thanks to the help of Fred, Seth, and others on the PC800 group, it is much better now but not entirely fixed.  The left brake (with the anti-dive mechanism) works correctly and makes just a little noise but does not drag.  The right brake drags and stops the wheel sooner than I recall it stopping before.  It also makes the bike somewhat difficult to push around without power.

What precipitated finding this problem was replacing both my front and rear tires.  Eventually I’ll post some photos of why I had to replace the tires before all of the tread was used up.

Fred suggested I try riding the bike to see if the right rotor gets very hot.  That would indicate a real problem and not just something in my head.  Before I take it out for a spin (hopefully this afternoon if I can find the time), I thought that I would put up a video of the wheel spinning.  Didn’t have time this morning to take the right brake off to show the difference but with the right brake off, the wheel will spin for a minute or two once I give it a good start.

What do you, oh Pacific Coasters, think of the spin on that wheel?  Is that acceptable?  This evening, if no one thinks it is obviously unsafe to ride, I will take the bike for a spin to see how hot the rotor gets and will report back on the PC800 listserv and possibly here, too.

UPDATE: IPCRCer Fred put his bike up on a jack and gave his wheel a spin.  It does the same thing as mine.  I plan to road-test my bike as soon as I have a free hour to see if the dragging is still a big problem or not.  Perhaps slightly dragging brakes are a feature of PC800s?

Air Box Oil Leak and Tightening the Oil Filter

 

I’ve been having oil leak from my PC for several months now.  Last year, I ended up having to replace the seal around the shift rod.  This time it doesn’t look like it’s coming from there.  Instead, I found two separate places that oil was leaking from.  The oil filter had become loose and appears to be the main source of oil.  I tightened it nearly a full turn.  Also the air box has developed a bit of a leak.

 

 

The telltale signs of an oil leak.

 

 

 

Oil was leaking from where I’m pointing my finger at.  The carb boots in the air box are not an integral part of the air box.  They are molded separately and then inserted after the fact.  Some sort of glue is used to seal them.  The glue on mine has gone bad.  I cleaned it up as best I could and re-installed it for now.  In a few weeks when I replace the air box with something different, I will make sure the new air box does not have a leak.  Incidentally, the reason that oil is coming out of the air box is because of the crank case breather tube.

 

 

 

 

Fuel Injector Bungs Done, Parts Received, etc

 

The electronic parts for the fuel injection project arrived on Monday.  The MicroSquirt, wide band O2 sensor and gauge, air pressure sensors, thermal sensors, and USB to serial cable all showed up as expected.

 

 

I finished drilling out the holes for the injector bungs earlier this week.

 

 

 

The bungs slip in nicely and are at about the same angel and position.  I plan to JB Weld them in once I have built injector bosses and made adequate provisions to secure them to the carbs.

 

 

 

This is my outdoor work space.  A Dremel too, cordless drill, and some sunlight are all that I need.  Sure would be nice to have a drill press or mill though…

 

 

Here is an injector in the bung on top of the test engine that Bart is loaning me.  It fits with plenty of room to spare.  The injector boss should fit fine on top of the fuel injector.

 

 

 

I’m using a screw driver to hold the injector in position.

 

 

 

 

The next steps is to build the injector bosses that will carry pressurized fuel from flexible fuel lines (most likely rubberized) to the injectors.  I plan to do that using brass and a mill.  I believe I will put NTP threads on the end that will connect to the fuel hose.  Need to go to an auto parts store and figure out the most inexpensive and safest fittings that I can use.  I will purchase other miscellaneous fittings at that time as well.  Another thing I need to do is purchase a fuel pressure gauge.  I plan to purchase a digital (so high pressure fuel isn’t snaking up into the dash) pressure gauge to mount on my dash.  Most likely it will come from Gaffrig Performance as their units are fully waterproof.

In order to hold the TPS in place, I plan to get a thin aluminum plate that I will mount it to.  The plate will serve as an adapter to allow me to mount it to the carbs in such a way that it will not interfere with the throttle cables.  I will have to machine a part to extend out the nut that connects to the shaft around which the butterfly valves rotate.  The first part is doable with a Dremel and hand drill.  The second part might require me to get time on a lathe.  I have a few ideas on how to do it by hand though.

The fuel tank still needs to be modified.  I’ve been dragging my feet on this one a bit.  It really *should* be welded rather than just using JB-Weld to guarantee that it won’t fail down the road and dump gasoline all over the exhaust system.  There is the guy in town who said he can probably do it.  Maybe next week I’ll give him a call again and take the tank to him for his assessment.  A friend with a MIG welder said he might be willing to give it a shot, too.  I don’t want to blow any of my friends up though 🙂

Modification of the air box for the MAP and IAT sensors will start soon.  That shouldn’t be too hard to do as the air box is plastic and the sensors are pretty forgiving.  The extra air box I bought is ready and waiting for what tortures I have in store.

I will need to fab up some brackets to mount the tip-over sensor.  Not sure exactly where I’ll put it.  Maybe somewhere up in the cowl.  I also need to decide if I want to purchase a knock sensor or not.

Sooner or later I need to invest some more time in reading about spark control.  I’m not sure if I need to buy additional components or if I can use what is already on the bike.  Hopefully nothing additional needs to be purchased.

The O2 sensor bung is going to be a pain to weld in place.  The friend with the MIG welder said he’d take a shot at it if there is enough room for his tool.  I want to weld it on the exhaust accumulator that lives directly underneath the fuel tank.  I plan to weld the bung in place when I drop the tank and rear wheel out.  Speaking of the rear wheel, I am in dire need of a new tire.  Hopefully I can get that on sooner rather than later.

This project is, I would say, about 1/3 to 1/2 way done.  Momentum should be picking up quickly as almost all of the parts are in and modification is going smoothly.  It’s just a matter of finding the time and the few odd scraps of metal I need to finish this up.