Forum

[Alan R]

Hello another me !!---------- just a thought, on the new "discs" check the depth of the spring cavity against the old discs. They should be the same. A few "thou" shouldn't make much difference but anything more( well actually LESS) will start to compress the spring more than intended. Try with the old shaft and the new pumps---ie is the new shaft giving problems ?? It's a straightforward set-up so can't be much wrong. Hope this helps some ??

[another Allan]

Good suggestion, Alan. I'll do a comparison of old v new. In fact, I'll also put all the old parts together and see how that turns - I may find a clue as to why the spindle stripped in the first place!

[Les H]

Hi Allan. I had the identical situation when I replaced my pumps some years back. I spent hours checking everything but nothing was touching or binding. Yet when I removed the timing cover and turned the original pumps before dismantling the spindle turned very easily. Eventually I fitted the end caps with two gaskets and although tight they turned. I fitted the cover made sure the engine could turn and started making sure I didn't rev it too much. After a while I just forgot about the pumps and they've been perfect ever since and thanks for reminding me that I still have two gaskets fitted I'm pretty sure just one will be ok now and even with the thicker spring fitted. I was going to buy another set and start the whole process off again just to get to the bottom of the cause of tightness. But like so many things I just have not had the time what with all the other bikes and all. So your question "What am I missing?"...well nothing it would seem. The pumps are just tight too turn with the thumb to start with. I have the weaker springs fitted too. It makes me wonder if the apparent effort is required to twist the springs themselves. The springs abut tightly against the pump body and locate on the oil pump spring pad in the end caps, so make sure you have some grease under the pad as the whole spring has to turn and the pad acts like a ball bearing allowing the twisting motion of the spring without too much friction. So I would just firt with two springs make sure you can turn the spindle through one complete turn by using a screwdriver blade carefully to turn the spindle and fit the cover with no gasket. Or use a dry gasket. Spin the engine over many times with the kickstart (Decompressed) and as long as the action feels reasonable free do it for about 5 minutes or take the bike for a walk in gear. Then remove the cover again (there might be just a tiny bit of oil built up and check the action. It is almost certainly to have eased off quite a bit..Must go now…let me know what you find…CU.

[Les H]

Oh yes Alan has reminded me. Check the pump outer surface when in place, it obviously needs the outer surface of the pump to lie below the level of the housing check with a steel rule...not need to do any measuring...they need to be a few thou lower than the surrounding ebge of the housing.

[John J]

Hi, I have had the same problem. The problem is that a not very well finished disc has to rotate on the ground end of a spring. this of course gives rise to a lot of friction. I think Mr H could help here.
If a disc,with needle rollers( like the clutch centre operator) was available with a shorter spring to suit then,the friction would be greatly reduced. Over to you Mr H.

[another Allan]

Hi John. A circular needle roller bearing sounds like a nice idea. However, does it really matter if the pump disc recess is rough? Effectively, the disc, spring and pad become 'one' due to the friction at each end of the spring, but as Les points out, the spring pad should act as a ball bearing in the pump cover. As long as this 'ball bearing' is smooth and lubricated, then it shouldn't present too much friction (says me, guessing again!) At least, it sounds reasonable to assume that that is what the components do in thousands of Enfield engines worldwide. Your needle roller would be a great thing to try, but maybe it only makes a difference during the early life of an oil pump assembly. Les H's experience suggests that the standard arrangement (even with double gaskets at each end) is still pretty impossible to turn by 'light thumb pressure' (contrary to what the technical notes suggest) but it does become much more free after running the engine for a little while. John, you say that you have had the same problem, but what's the current state of play with your oil pump? Has it freed-off after running? I shall wait for the weaker springs to arrive in the post, and then put the whole lot together again, following Les's advice.
I'll update you all with the results!

[Bomber]

First time poster,long time reader of this site.My 1960 Bighead is what? 50 odd years old and I recall looking at the pumps once for curiousity but otherwise untouched from the factory,Replaced the main bearings when the cages got wore thin, the floating bush is original from Redditch.When I restored the bike for road use in the 80's I actually rode the thing for about 500 miles with no cork seal and a feed plug from a twin that some previous owner installed so almost no oil pressure, just the flow.Seems there is a lot of discussion about modifiing just about everything.I believe that the original design is fairly bulletproof not that discussing how pumps etc work doesn't make for interesting reading.Tom

[another Allan]

You make a fair point, Tom. My situation is a bit different, in that my engine has already been modified somewhat: 625cc, steel conrod, roller big-end, big inlet valve and ported head with 32mm carb, high lift cams, proper main bearings etc. Hence the reason to look at the high-capacity oil pump, especially as the original oil pump spindle expired. Recently acquired and not even run-in, although there are indications that the first owner may have 'messed' with it. It'll be pretty lairy once I've got it sorted!

[Norm]

Bomber, good points but as a long time reader you would have observed that only a few English Bullets seem to need rebuilding here, not sure why may be better built or ridden less, but 98% are Indian built and that can come down to the fact they are ridden more often or not built so well or a combination of both. I know of so many that never made 10,000ks without a major failure

[Bomber]

I'm sure a lot of of the English bikes suffered under poor ownership also. I give my head a shake when I see someonr riding around pretending their Bullet is a mini Harley hammering away at next to no revs in too high a gear and bragging how low they can run it in high.Thats got to play heck with the bearings, plain or not.I have a '95 that had its main bearings disposed in this manner by P.O..Running my Bighead below 50mph on stock gearing would be simply abusive.By all means modify away, we're not in this hobby to be like eveyone else anyways.