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By Alan R
#10598
Hello again "young" Mr Wallace--- Standard question---standard answer.  Engine = 20 / 50 mineral ( Change oil & filter at service intervals ) with a magnet & space filler within the filter. Gearbox = if as supplied then the "grease"  as reccomended BUT }--- have spoken to several who have fitted our hosts sealed bearing kit and now use 20 / 50 in there as well.  One thrifty Yorkshire lad apparently uses that in his primary chaincase as well giving 1 common oil available anywhere at anytime. Myself, I prefer ATF both in the primary and the front forks. I'm planning on giving the box all the improvements that MrH has in one go.  The sealed bearing and the improved ratio are particularly useful I think. That 750/4 rattle might well have been the clutch basket. They were known for this---especially at idling. I've had a '76 K6 and currently have the Hondamatic version--- a giant "twist & go". It's just like riding a big 2-stroke. Shut the throttle---the sound changes but you just keep going at the same speed. One of our club guys has a later F2 is it  ??  It's been around the clock once and is now at 30,000ish into the second time. 
By Alan R
#10600
Hi Simon----there are 24mm (350 cc) & 28mm (500cc) Mikcarbs fitted which are Indian built, licenced versions of the Japanese Mikuni carbs. As you mentioned earlier these carbs do tend to reduce the engines available power due to their relelative small sizes. On my standard 500 the inlet tract, as-cast, is actually 32mm.  But of course it's all about balance between air filter, carb, cams, compression ratio, silencer,  not to mention fuel type, ambiant air temp (and pressure)---- and most difficult of all}-----expectations of the owner/rider. You can have an on-board computer do it all for you if you like. But do you really want that-------------- ???
By Norm
#10601

 Alan,


    jumping back to the F2's any idea what makes them an F2. I have 2 off them, but never really found out why they are called that. I have a feeling that they may have been factory fitted with the police fairing. Great bikes, dead boring to ride, go, stop, turn and gets you where you want every time

By Alan R
#10603
Hi Norm--just caught me off to bed ( then in the morning I'll have to go home I suppose !! ). I have a couple of reference books on the single cam 4's---one by John Wyatt whom I know very well. I'll have a read-up and get back to you. Busy day to-morrow. A CB250 to road- test and book in for MoT. A  PC50 barrell and piston to drop off for re-boring en-route. A change of silencer on the Bullet-------shopping----------- laundry-------- feed the cat and all before dinner time !!!
By Norm
#10605

 Hi Alan,


       Don't worry about reading up on SOHC's the pair I have are DOHC's and as Wallace mentioned early eighties I assumed he was talking about the 79/82 DOHC  F's  The reason I liked them is because everybody else didn't, so they are cheap because the cam/bucket shim setup scared them off

By Norm
#10606
 And then seeing Wallace started this I wish i could stick a couple  Amals on the Honda instead of the Khein CV's they put on that model There is about 400 parts in them compared to the 5 bits in an Amal
By Alan R
#10617
Hi there Norm------The hardest part re}--- bucket shims on my Triumph (Hinkley) Thunderbird tripple was the shims themselves. The local Triumph agent wouldn't sell them to me saying "only they could get them from the factory" and "it's a special job, sir" etc, etc.  The fact that at that time I was working only a few miles away as a Civillian Senior Craft Engineer for the MoD on 4.2 Jaguar twin-cam engines doing exactly the same thing every day cut no ice-----they were going to have the work regardless.!!! Sign of the times I'm afraid. Looks like there's more "creeping" legislation in the pipeline re}--restricting the amateur home mechanic working on their bike / car etc in case of what might happen. 

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