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[Harald]

Affirmative.
I will replace the oil pump, it's gasket and O-ring, as well as the rocker arms and rocker bearing sets and once more check all the holes and channels for the oil supply of the cylinder head.
The first engine test afterwards will be done without rocker covers installed to check if there will be a sufficient oil supply to the rocker arm tips at the valve side what is obviously not the case now. I will especially check for any oil leaks around the rocker bearings. If all is fine, the rocker covers will be installed and a test ride done like the last time. Afterwards I will de-install the rockers again and check for wear. If there are still signs of abnormal wear I will make a change to the RH engine cover so I can temporarily attach a pressure gauge and check the oil pressure. The next steps depend of the results of the measurements.

[Rattlebattle]

Blimey Harald, what a lousy experience you've had with your RE! One of the things that struck me when I dismantled my engine for a rebuild was how oily everything in it was. The positive feed to the top end way surpasses the dribble we used to get on old British bikes, where the feed comes from the return side. My rocker shaft bearings were perfect. They didn't have o-rings and just kicking the motor over a few times caused a flood of oil to emerge from the hole in the top of the barrel. An easy check on a running motor is simply to remove the faux tappet inspection cover with the engine running; then spend the next 15 minutes mopping up the oil......At least on these engines the rocker shaft bearings can be replaced, so no trashed cylinder head like a lot of ohc engines (Himalayan? 650 twin? - anyone know?). As you know, the oil pump delivery o-ring is critical on these bikes; at least your problems have highlighted the fact that if the o-ring leaks it's the valve gear that suffers, not the crankshaft/big-end. The other critical seal is the one in the outer timing cover in the centre of the generator. I renewed this as a matter of course as I would imagine a leak there wouldn't be good news. It's a weird brown, fairly hard seal that RE recommend is changed at 20,000kms. Anyway, good luck with it.

[PeteF]

Mr H does a "tappet cover" with a clear window. Quite expensive but it should show if sufficient oil is returning down the push rod tunnel.

[Harald]

Thanks again for the hints. I will check the seal in the middle of the generator - a seal I did not have on my list until now.

When you remove the faux valve adjustment cover when the motor is running you will have a shower of oil - and a lot of fun cleaning your garage. Guess why I know this .... .
This was my first test and all looked fine, but it is telling only that oil is delivered to the cylinder head and returning to the sump. After removing the rockers, it was obvious that the lubrication of the bearings was quite good. The aluminium of the bearings was not worn so bad, only a few scratches, but the tip of the rocker arms where they touch the valves showed heavy signs of wear.
As the small channels in the rocker bearing blocks from where the oil should squirt to the rocker arm tips had a free passage, the oil pressure has to be too low to give a good spurt of oil in this direction. I will explicitly check this when installing the new oil pump and rockers .
My impression is that there is a lot of oil in the rocker bearings, but not reaching the rocker arm tips. A low oil pressure or a leak somewhere may be the reason. One more (theoretical) possibility is that the oil feed channels to the rocker tips are drilled in a wrong angle so the oil may splash out, but in a wrong direction. I will have to check it also.
I ordered a pair of good used rocker sets from our host that definitely already worked fine in an UCE without a lot of wear. I will install them and have a look if there is any difference to the ones originally installed in my engine. May be this test will bring new findings.

[Wheaters]

Is it possible that rather than a lack of oil, the wear might be caused by faulty heat treatment of the rockers themselves?

[Daiwiskers]

I have been looking through the pictures again

Rockers don't need a lot of oil but there's a lot of wear where they contact the valve !

Are these engines fitted with valve caps or should they be?

Could they have been missed on the assembly line?

I'm sure some of the later engines had them fitted

Glad you finally have got some sense from Royal Enfield Dai

Edit Just had a quick hunt through the online parts book and can't find any valve caps

[windmill john]

So, I ask the question.... bearing in mind this is an enthusiasts forum.... would you still buy a new 500?



John

[Harald]

The importer sent me some new parts and today I installed a new oil pump. The factory O-ring at the oil pump outlet was of low Indian (factory) quality and I replaced it by a German product made from Nitrile butadiene rubber (NBR 70). You can find such O-rings in industrial supply stores.
Making a long story short : After reassembling the engine and fill it with the correct grade and amount of oil the ticking sound and all the irritating noises had gone and the engine run very soft.
I hope this information may help some RE enthusiasts out there. And do not believe a dealer when he tells you that a ticking sound from the valves in an UCE is quite normal!

[Rattlebattle]

Glad you got it sorted Harald. I find it a bit ironic that a bike made in India has such rubbish rubber parts, though really I doubt they should be rubber anyway. I’ve had to replace the tank vent hose on mine and, if ever Hitchcocks restock the crankcase breather hose, I’ll replace mine because it’s cracked and beginning to crumble. Either that or I’ll fit a breather vent. You’re right, the valve gear should be quiet on these bikes. If it isn’t, either the backlash needs adjusting or something is wrong. On the subject of inferior parts I know of no other make that has a specialist supplier offering for sale superior replacement main and gearbox bearings - says it all really ....

[stinkwheel]

Thanks for keeping us updated.