Thanks for this. Which NGK plugs do I need. Is it just the clip that needs changing. Sorry still learning. Any pointers much appreciated
If you dont know what cam, the answer will still be that all the cam lobes should be the same lift, so all the valve stems should move up and down the same amount. The balance pipe is needed because the cylinders fire in pairs 1)(43)(21)(43)(2 so one cylinder each side gets starved of fuel because its neighbour just fired. The pipe provides extra flow for the second cylinder each time. The asymmetric front/back exhaust pipe lengths on a stock exhaust also dont help.. its the classic putt-putt sound with every other pulse coming down one of two different pipe lengths. Its also a problem with centre mount carbs, but there you cannot fix it.
I wouldn’t worry about what cam is in the engine – I was just pointing out that looking at the adjusters doesn’t tell you if the cam is worn or not. But if the adjusters are uneven it can be an indication of valve seat recession or stretched valve stems.
Pancake filters are restrictive, and yours look like they’re haven’t been cleaned for a long time. I’d chuck them away and fit taller filters, but refit the fuel and crankcase breathers in the new filters. The hose clip you have on the crankcase breather is too big and will distort the hose, no big deal but when clips are so cheap you might as well fit the correct size. Then you won’t get nitpickers like me making comments. NGK BP6ES plugs should work fine in a type 4.
