B25 Work and Log Restart -------------------------- Log ReStarted Spring 2019 Current Rev. 21-Sept-2019 The B25 was last operated in the summer of 2014. It rested in Rm 1200 during the summers of 2015, 2016, 2017, and 2018. It must move out of Rm 1200 during the summer of 2019. The issue is to push it home or do the work to get it running again. The known issues are: - Before running need to change: engine oil, transmission oil, primary case oil, - Its battery is dead and will not take a charge. - Rear tire is bald. - Transmission output sprocket is hooked. The 50 year old rubber oil lines are not in very good shape and should be replaced. When putting on a new rear tier should one also take the rear hub apart and replace its bearings ? The rear wheel bearings have never been re-packed. When replacing the transmission output sprocket does the rear wheel drive chain also need to be replaced ? Drain the engine oil, transmission oil, and primary case oil. Well clean the oil tank, the oil tank filter, and the two old oil hoses. The front tire is a 3.25" x 19" K70 on a WM2.19 rim. The rear tire is a 3.50" x 18" K70 on a WM2.18 rim. Both of these are the original tires as far as I know. The front tire still has some tread but the rear is bald. The rubber of the front and rear tires is dried, hard, and powdery. The external width of these WM2 rims is about 2.65" or 2.66". The x.yz part of the tire number is its Width, e.g. 3.50. The aspect ratio of a tire is Height/Width. Normal aspect ratios are 1 or less. The Inner dimension of various WM Jones Rims is: WM1 = 1.60", WM2 = 1.85", WM3 = 2.15", WM4=2.50". Dunlop no longer makes a 3.50" x 18" K70 tire. Dunlop does make the following K70s among others: Recommended Overall Tire Rim Tread Width ---------------- ----------- ----------- K70 3.50" x 19" 2.15" 3.78" K70 4.00" x 18" 2.15" 4.17" Measuring the old 3.50" x 18" K70 currently on the bike is get: Tread Width = 3.45" Full Width = 3.75" So both the very old 3.50 x 18 on the bike and the current 3.50 x 19 have an overall width of about 3.75" and a new 4.00 x 18 has an overall width of about 4.17" so a new 4.00 x 18 will stick out about 0.21" on each side. Probably need a new tube and rim strip at the same time. Would be less risk to the new tube if I had some actual "tire levers", e.g. 29-9252, 45-10214, 60-0801, 68-9463. The rear wheel bearings are: 1x LS.9 and 2x LS.9RS These are Hoffman bearings 65-5883 41-6016 41-6017 41-6016 These bearings are: 7/8" x 2.000" x 9/16" deep grove ball bearings. ID OD Thick The RS in the Hoffman number probably means "rubber seal", i.e. a "sealed" bearing. Sometimes this is: 1RS or 2RS. A "ZZ" suffex in the part number means a Shielded bearing. The transmission output sprocket has 16 teeth. That is standard for the B25. It is part number: 41-3095. In its final B50 version I think this is 57-2701. The transmission output sprocket has never been changed that I know of. The rear wheel sprocket has 49 teeth and it is a sprocket that I bought new probably in the 70s. The rear wheel drive chain is: Reynolds No. 110054 which is 5/8" x 1/4" about 100 pitches that I bought new in the 70s. I do not know if it has "stretched". This is not a modern standard ANSI size chain. Its modern chain number is #520 but this is not a standard size, e.g. from McMaster. The battery is a NP5-12 Newark 29C7223 $25 107mm tall, 90mm wide, 70mm deep 1.81 kg 12 Volt 5 AHr Battery charging voltages: Float Cyclic Charge Charge ------ ------ 25 deg C 2.265 2.435 30 deg C 2.250 2.420 In both cases the temperature coefficient of the recommended charging voltage is about -3 mV per Deg C. The oil tank to pressure pump hose is 3/8" ID. The scavenger pump to oil tank hose is 5/16" ID. British Cycle Supply Customer Number: E00880 221-15 Tire Levers 7" spoon type Qty=2 $ 13.17 555-400x18/K70 Tire Dunlop 4.00" x 18" K70 Qty=1 $126.74 556-400/425x18 Tube 4.00/4.50x18 inch Qty=1 $ 16.52 557-2 Rim Band WM2 Qty=1 $ 2.00 57-2701 Sprocket B25/B44 16 tooth Qty=1 $ 45.81 97-2513 Fork Gaiters Pair $ ??? ------- $217.41 Executive Summary of work done in the summer of 2019 to get the bike running again and out of the lab: ------------------------------------------------------ - Replace the battery (see above) - Change the engine oil including taking the tank and sump tank off and cleaning them. - Replace the black oil tank to/from engine hoses with clear tygon hoses that have woven reinforcement. The standard setup is 3/8" ID for the tank to engine hose and 5/16" ID for the return hose. I used 3/8" both places with a layer of heat shrink on the return pipes so that they fit 3/8" ID hose. The black rocker box feed hose was not changed and so far it looks OK. A concern with the rocker box hose is vibration caused cracks. I still need to prove that the tygon tubing is long term oil and high temperature safe. - Change the transmission oil - Change the primary oil - Replace the gas tank to carburetor hose with a piece of new 5/16" ID black hose that it routed so that it does not have a low spot in the middle. This new setup looks better than before. - Clean the carburetor and one must be very careful re-installing its control cables to verify that the knob on the end of the inner cable snaps into place. Note that I put the needle valve clip into the next to the top position out of the 5 positions available. This is the next to the leanest position. I forgot to check what position it was in when I took the carburetor apart but I'm sure that the clip was in either the top or the next to the top position, i.e. lean. - Oil all control cables - Oil the spare clutch cable. Note that the clutch cable in use on the bike is 53" full length end to end of its shield. The spare clutch cable is 57" full length end to end of its shield. - Change the folk oil. The drain oil from both forks looked clear with no water. - Cleaned the oil and dirt from the cylinder fins and head. - Clean the points and points cam and re lubricated it. - Oiled the chain with 90 weight - Notes: The rear tire is in very bad shape. The front tire still has tread but is 50 years old. I filled the tires to about 22 psi front and 23 psi rear. The transmission output sprocket (16T) is somewhat hooked. One of the gaiters has a split (the one on the throttle side that did have water in its fork oil at one time). These gaiters are for the shuttle valve forks and the ones on the bike have 14 full ribs and a half rib at the base. They should be part number: 97-2513. The hand grip on the throttle side is still loose. I still need to make a real adapter for the headlamp bulb. The bike left Physics on 1-Sept-2019 (2 kicks).