Tuesday, May 26, 2009

WWII BMW R35 valve adjustment,kicker gear replaced

Foto of BMW R4 , very similiar to R35, R4 has leafspring forks similiar to Indian motorbikes
Right side shifter on R4.

Foto above of nut i overtorqued renderering the rear wheel frozen, wont be making that mistake again.
After some 60 years of service ,everything wears out, After the valve service, new valves , pistons, bore, valve adjustment,,, the kicker gear wore out and stuck., no movement.

New kicker cover w new kicker gear, could have just swapped gears but i got the whole assembly.

BMW R35 after tear down.

kicker gear on trans is excellent.

Kicker gear shredded after million starts,this locked up the kicker so no movement.

I got this Bing carb, i have never ever seen another one for sale, best little carb i have ever used.
new Made in Germany gas shutoff also. Why if you were an engineer would you put a gas shutoff directly above a battery? Nothing like putting out a motorcycle fire w a Pepsi.

BMW R35 350cc cylinder, remove the top half of engine lid and gas tank to service valves.
You could just remove that front 2 bolt window, but its just easier to pull the top lid and tank and do it right.

Here you can see the tops of the pushrod tubes, you can almost check valve clearance like in a Knuckle or Pan, roll the pushrod tubes in the relaxed state,not alot of play , just enough to roll the rod in your fingers.

Valves and rockers w lid and gas tank off.

At one oclock in the foto, feeler gauge at valve, loosen nut w ratchet, adjust pushrod tube nut w wrench to correct valve setting, tighten rocker top nut w ratchet. Roll pushrod tubes w your fingers, doesnt get much easier than that, Idiot proof.......

Wednesday, May 20, 2009

1941 BMW R12 runs again after 50 years. setting up valves and magdynamo timing

Some fotos folks sent me on wartime BMW R12 bikes .

What is the location of this foto? my guess Southern Germany,or maybe Caucasus or Ural mountains...the mountains in the background are the only clue..

The BMW R12 engine when viewed from the front, rotates in the clockwise position, i had to find the correct R12 mag/dynamo that also rotated in the clockwise orientation for the mag to spark.The mag that came w it was a counterclockwise spin so it must have just been thrown in to sell the bike to the fellow i bought it from. No way in hell was it going to start spinning the wrong way.

After at least 50 years, the ww2 BMW R12 came back to life, serviced the cylinders w new valves, pistons, serviced the mag/dynamo. Carefully after much trial and error set the valves as in the foto above between #35 and the valve end ,.The original manuals call for one to fit a piece of paper between #35 and the valve end, Looking into the spark plug hole w a very bright flashlight , i could see the piston get w/in 10mm of TDC,as the piston ascended to the TDC position. remove spark plug wire terminal from mag, rotate mag sprocket until one is in the middle of the brass portion that is visible,thats where the point just starts to open, install mag, prime and kick started back to life. Theres plenty of great part sources in Germany and some very good online sites w proper instruction, The throttle control or "gasgriff" was worn out, the internal slider in the original Sum carb or Sum vergasser was sticking,so those parts will have to be ordered. should be a daily rider if there isnt any other big issues. W proper instruction its a relatively easy service.
There are R12 bikes w 2 carbs , this is a single carb bike. Be great to post a foto of a twin carb engine.

Here you can see where to check your valve gap. needed a 15mm, 13mm and 12mm wrenches. i found removing that inside center cylinder nut made it easier to make the adjustments.Position the valves at the relaxed position, then back off the 15mm "nut" closest to valve end. lock the 13mm lock nut against it, and valves are adjusted. By far Knucklehead valve adjustments are thee easiest.
It was kool to bring another relic back from the dead.

Tuesday, May 12, 2009

1955 Porsche runs w Pertronix ignition

Clearly visible is the characteristic bent window for 1953,1954 and 1955. Before 1953 the windshields are "split window".Plenty of work ahead. Running 912 engine, superior oil pump over the 356 engine for starters. Solex carbs,12 volt system. very reliable.
After the 3 ohm Bosch blue coil failed for unknown reasons i replaced it w a Pertronix 45,000 watt .6 ohm coil, adding this to the Pertronix electronic ignition, swapped out the original 1955 ignition switch and starter push button for replacement Bosch ignition switch which had a different wiring pattern and a 15 amp push button starter.Hotter spark at the plugs, Now its trouble free starting. The Bosch coil would bench test fine as a working unit , but under a electrical load the primary or secondary winding failed, I would certainly buy another Bosch coil if i needed it, just bad luck it failed, I wouldnt go less than 15 amps on the push button, for some reason they smoke and fail at less than that amperage.I also used a Dremel tool w the mini steel wheel to polish the fuse terminals and fuses, believe it or not it restored the signal lamps.
If your going to replace the electrical, best to swap out everything, the old components had some 54 years of service, if they weren't going to fail today they certainly were going to fail under stress at a very inconvenient critical time.

The muscle car Cragar ss rims, tires finnally failed , the front tire started wobbling , like it was gonna catapult off. Originally the 1955 would have ran 16 inch rims , I'm just building a runner so , 15 inchers are fine,, 165 65 r 15s would be original but they are actually not a very common tire so i added, 185 65 r 15s, common size and the same as a 1963 Alfa Romeo uses, The car can fit 195 65 r15s .
The flares gotta go , i have complete qtr panels to swap them out w... Turns out the car was amateur raced in Riverside and Arroyo Seco in the Southland. The fellow ran a Corvair engine which is similiar to a VW or Porsche air cooled engine. The VW trans turns out to be original to the car. Hooking up a 912 engine to a 1955 VW trans was straightforward. the carb linkages had to be made to fit and work. I always hated Solex carbs on 1950s-60s Alfas but on Porsches they are fine units.