Hitchcocks Forum

My classic bullets oil spindle failed recently and now repaired and running the engine doesn't feel so sweet. I think the big end may be cream crackered so I feel a rebuild coming on. To improve the bikes vibes and comfortable cruising speed what are the best mods I can do whilst apart and what gains can be had? It's already far from standard with Amal,boyer,alloy barrel,goldy pipe etc but I don't know what's inside the lump yet! I presume a roller big end but is it worth lightening the flywheels? Does that allow more revs if true and well balanced? I'll be starting a strip soon but what won't be possible without specialist tools? I do regard myself as a reasonable self taught mechanic with a good collection of tools but non specific to Enfields! HARVEY EAST YORKS

Hi Harvey. Lightening the flywheels is one of the best all round improvements you can make [well, I would say that, wouldn't I]. Here are some reasons for that I can think of. 1 faster acceleration. 2 livelier throttle response. 3 Main bearings get an easier life. 4 Your brakes will feel more effective, due to less flywheel inertia. 5 Reduced likelihood of pinking when you open up the throttle suddenly. 6 less overall machine weight, with a couple of pounds shaved off. 7 NO, repeat NO loss of torque, plodding power, or anything else - the crank will still be heavy in comparison to more modern singles! I will now sit back and wait for all sorts of reasons not to do it, but I can't think of any, unless you use your Bullet to haul a chair, of course! Regards, Paul.

4 should read 'Your brakes will BE more effective'

Thanks Paul, so how are they best lightened and how much weight can be removed?

I Just spent a few quick minutes starting work on the bike only to find that I can't get the rear rocker box off due to the frame so that's a good start! Will I have to loosen the engine mounts to get enough space as a long stud is preventing the cover coming off? I thought I'd start by trying to remove the head with the engine still in place?

Harvey

Hi Harvey, I machine the flywheels down in the lathe, from the inside face, outside face and across the rims. I can usually remove around 3 lbs or so from a 500 crank, overall in this manner, but I have to drill extra balancing holes afterwards, to restore the balance factor. Regarding your rocker cover, if there is enough gap when you lift the cover from the head to grab the shank of the stud through the gap with some pointy type mole grips, you may be able to remove the stud first, to allow the rocker cover to come off afterwards.
Regards, Paul.

Sounds like you have done a few then. when I get time to take it apart I"ll maybe require your services then Paul. I had the same idea re the rocker stud but noticed it bending like cheese so they don't look very strong! I" have ago tomorrow if I find a few spare minutes?
Looks like I have samrat rockers so nowt special under the covers sadly. One slightly bent rocker adjuster too. H

Hi Harvey , if you get stuck for factory tools , I have some of them , cant remember exactly which ones I d have to check !But I m near Selby and you d be welcome to borrow them if that helps
cheers

Hi if its an iron barrel you can get rocker covers off my first attempts were the same as you but I found you can wiggle the inlet one off, ex is dead easy inlet you have to have it in just the right position sometime I can pop them off and on easy other times its a 10 min shit fight theres not much in it but it works. I also did the pump spindle on a 94 bullet a few weeks ago new 535 piston , rod and floating bush also new main bearings and pump spindle and drive nut. Not a very hard motor to pull apart, bearings are readily a ailable from bearing suppliers, you need someone to align the crank might pay to have it balanced at the same time to 63% well worth it. Happy fiddleing.

Finally got the head and barrel off to find its not standard internally. The samrat rockers had loads of alloy filings in them and the head has 41mm and 44mm valves in it. It's signed LN 99 so I suspect that it was rebuilt 1999.The bore is not worn but has some scoring front and back and appears to measure about 83.5mm? My calipers won't that accurate. Piston is an acralite one with a domed top with deep cut outs so high comp? On the top edge of the piston is some damage to the alloy but it looks like a couple of gouges taken out before it was fitted? I think most would condem it. The little end seemed quite loose in the conrod allowing a bit of movement although not much up and down. It looks like only the rod eye has worn. The big end does not have much movement. The conrod is alloy so softer. Bad news is I dropped a stainless washer down the case! On my drive side the spindle is not running true as bits of my alternator insulation has rubbed off so I guess I'll need to do a total strip anyway. Now I need measurement advice.

Thanks for the offer Phil I know Selby area well as I went to school there. Getting the drive side apart may need tools! Harvey