Wear Your Helmet
Whether it's the law where you ride or not, always, always, always, wear your helmet! No exceptions.
Use Your Headlight
Next to wearing a helmet, the one most consequential thing you can do to increase your survival odds on the road is to travel with your lights on at all times.
Maintain Your Motorcycle
Go through this checklist before you ride to ensure a fun, safe ride.
- Check the pressure in your tires every time you ride. Under-inflated tires wear quickly and affect the handling of your bike.
- Check your fork seals. Fluids from leaky front forks can drip onto the brake rotor, rendering your brakes useless.
- Make sure the chain is lubricated and adjusted properly. A loose or worn chain can jump off the sprocket and lock up the rear wheel. Check steering head and swingarm bearings regularly.
Ride with a Partner
Riding with a partner is more fun and much safer than riding by yourself. This is especially important for new riders. Try to go with a seasoned motorcycle rider for the first few months at least.
B25 Modifications for Reliability
Part 1: Crankshaft
I am starting this article with the crankshaft as it is the first thing in the engine you will be working with if you are rebuilding it. Remove the the connecting rod, being careful not to nick the rod journal, and then remove the 8 flywheel retaining bolts and tap the flywheels from the crankshaft—you will notice the sludge trap has the usual mung in it, so clean this up very good, but it is not necessary to remove the plug from the right flywheel, as we will be eliminating the sludge trap in our modifications. Measure the rod journal to be sure that it is round and not undersized. If it is, this will need to be ground to the next undersize at this time. Drill the rod journal oil feed holes to .125" and chamfer the hole on both sides of the journal this will assure an adequate supply of oil to the rod bearing. Next in the drilling of the crankshaft where the oil ports intersect use a .437" drill and drill this drilling another .312" deeper and deburr all edges. Now you will need to make an aluminum plug to block the oil port from the crank to flywheel joint, measure the rough opening hole in the crankshaft, usually these are about .442-.445" and make an aluminum plug .001-.0015" larger than this hole about.500" long and cut the tip that is being inserted into the crank on a 45º angle so that it will clear both oil ports, now press this into the crankshaft checking with compressed air that you haven`t covered the oil ports, this should leave you with some of the plug remaining above the crankshaft, file this even with the surface of the crankshaft. If you think it is necessary to prevent leakage you can cover this plug with epoxy. Now after cleaning the sludge trap in the right hand flywheel mix up a batch of epoxy and fill this void flush with the mating surface, after curing you can finish off any excess with a sanding roll. This is done to be sure that for some reason the plug you just inserted into the crankshaft cannot back out once the flywheel is in place. After making sure that every part is very clean you can reassemble the flywheels to the crankshaft using Loctite on the mounting bolts and torquing to 50 ft. lb. Now insert the new bearing shells into the conrod and using either assembly lube or motor oil install the rod on the crank and torque the nuts to 22 ft. lb. What this modification does is eliminate the leaking joint at the flywheel to crankshaft surface that bleeds off oil pressure and makes sure all of the oil is going to the rod bearing.
Part 2: Crank Case Mods
I have noticed that many of the B25 oil feed ports leading to and leaving the oil pump are undersize, some more than others. After removing the threaded fittings from the bottom of the right hand case (or bolt-on oil manifold on the pre '71 models) drill out the oil feed port to .1875" all the way to and including the oil pump mounting surface as the hole here is also smaller than the opening in the oil pump. Now drill on an angle using the same drill bit into the port that feeds the port going to the inner timing cover, not too deep, just deep enough to intersect the port going to the timing cover now from the timing cover gasket surface enlarge the port that feeds the inner timing cover all the way to the angle drilling you just drilled from the pump gasket surface.This will ensure that you have a large enough quantity of oil feeding the crank as this is as important as the oil pressure because without volume you will have no pressure. Now enlarge the return port coming from the pump back to the reservoir to .220". This last mod is for racing purposes only and not recommended for the street. On the bottom of the case in the sump area drill out the pickup to .220" and remove the check ball and discard. If it isn`t all ready cut on a 45º angle, cut the pickup tube on a 45º, this will ensure full evacuation of the oil from the sump.
BSA A50/A65 Oil Pump Installation Tips
Please read the following before installing a pump.
The BSA unit twin oil pump installation is more than a bolt it on affair and go. I have found over the past 35 years or so that there is a sequence that should be performed to be sure that the pump will work correctly without binding. Do this with the crankshaft pump drive gear removed from the crank shaft, install this after the pump is installed.
This will require you to make up some makeshift tools to simulate the engine running so that you can visualize what is going on with the oiling system. If the engine is installed in the frame you already have the oil reservoir to feed oil to the pump if not I use a short piece of hose and a small funnel to feed oil to the pump( use a long enough piece of hose so that you can attach the funnel to the rear and above the pump level so that oil will gravitate to the pump). Now make up a short pump drive that will clamp onto the tach drive, I use a ¼" hose about 8-10" long with a ¼" or 5/16" stud pushed into one end and clamped so that I can use this to attach a drill motor to then clamp the other end onto the tach drive) If you have a 1969 or later engine you can attach a oil pressure gauge into the case and monitor your oil pressure and the blow off point of your oil pressure relief valve making sure it works correctly.
Start by filling your funnel with oil then spinning the drill to the right you should see the oil in the funnel begin to fall meaning the pump is pulling it into the engine (sometimes if the pump wasn`t filled with oil prior to installation it will cavitate and not want to pick up the oil in which case you may have to wait for the oil to work its way into the pump) now watch for oil bleeding from around the crank and right hand bushing area, this is normal, also look for oil leaking from the pump itself either at the body to drive snout junction or the end cap, a small amount of weeping here is not something to be concerned about with 50# of pressure but a profound leak is. If you have a 1969 or later and have installed a oil pressure gauge check to see what your peak pressure is, this should be in the 50-60# range. If the oil pressure relief valve is working correctly you should see the bypass oil bleeding away also into the sump area on 70 and earlier and into the return pipe on 70 and later. I also like to attach a hose to the pickup tube and insert this into a can of oil and test the pickup to be sure the scavenge is working too.
If after doing the above tests everything seems to be in good order then you can install the oil pump drive gear onto the end of the crank, because this threads on it will require you to index it with the worm gear in the pump drive housing, just be careful and turn the worm gear while threading on the pump drive gear so that the small teeth of the drive gear roll smoothly through the worm gear, after the leading edge clears the worm gear it will thread right on, tighten securely install the lock tab and jam nut.
WARNING: the torque figures for these fasteners in the manuals is incorrect, the worm gear should be 30ft lb maximum and the jam nut no more than 20ft lb
From here on it is standard assembly of the intermediate gear making sure the cam timing is correct then install the inner timing cover, tach drive, etc.