I've recently noticed oil leaking from the oil filler cap on my RR7. I fitted some R & G engine covers during January, and since then I have seen the oil running down the cover. I took the clutch side R & G off to investigate, but found that it was the filler that was the origin. I refitted the cover and made sure the cap was screwed in tight. Had a couple of rides out over the past couple of days and still the oil appears. Renewed the "O"-ring on the cap before yesterdays ride still no joy. What I have done now to see if it helps is put a larger diameter "O"-ring on the cap so that it sits between the flat of the casing and the flat of the cap, rather than tight around the screw thread of the plug, as there is a countersunk portion on the filler hole where the standard size "O"-ring sits and it feels like the cap is maybe bottoming out on the shoulder of the casing before the seal gets compressed and letting oil past. I'll be having another run out today so will see if/how the larger seal works. What puzzles me is that the leak should start now, it never leaked before fitting the R & G covers, yet the hole in the plastic cover is clear of the plug and shouldn't be making any difference. My only theory is that the plastic covers are retaining heat in or preventing air cooling the alloy clutch cover causing it to expand slightly and so reducing the compression of the oil seal on the filler letting oil either blow by under crankcase pressure or from being flung up at high force by the spinning clutch. I did originally think that I had, maybe, trapped an engine breather pipe when I did the flapper mod last year, but I would have seen oil long ago. Over to you guys....any ideas ???
I have an rr7 and the same r&g covers but have never seen this happen. Did you torque the bolts when you fitted the cover? My bet would be that it is leaking behind the cover and is then escaping through the filler hole as that is the main/only open route to it.
That was my first thought, which is why I removed the plastic covers and checked, but there was no oil on the inside to indicate that it was leaking elsewhere and tracking up to the filler hole, no oil around the alloy cover either, the only place where oil was present was at the bottom of the plastic cover where it had run down. When I refitted the covers after I first noticed the leak I made sure everything was nice and tight...
TOm.. same thing happened on my RR6. Every ride, I noticed a small oil leak on the standard covers after I got home from the Oil filler. I bought a new o-ring for the filler cap from honda, and its cured it..
I did change the original "O"-ring for a new one as I said, but it still leaked past.. !! The engine only has 5500 miles on it, I realise that is no guarantee that the engine won't develop a pressurisation issue, but it's highly unlikely.
another point to add was that I changed the o-ring as I got rid of the PAIR system - or about a month apart so it also may have contributed to stopping the "pressurisation"
Just thought I would update on this issue. When I went out for a really decent ride the other day, I got home find my right boot covered in oil, so the O-ring upgrade never worked. So today before I went out I had another look at the leak. I took off the R&G cover and found that it wasn't just at the top of the case that had oil but also the front edge nearest the radiator. What I discovered was that the original Honda bolts have a flange at the head and this obviously goes tight up against the alloy case. What was happening was that the longer bolts supplied by R&G were allowing oil to work it's way up the threads and as the plastic cover isn't a gasket tight seal, oil was leaking out of the bolt holes and appearing at these points around the case, the oil filler hole has a bolt just in front and this was making it seem like the filler was leaking. Anyway, what I have done is re-fitted the cover with the R&G bolts but put a copious blob of sealant, (the stuff that is used to seal the clutch cover not silicon), on the threads. Been out for a 30 mile ride and so far, no more leaks....fingers crossed. So if anyone else is having similar issues....this could be the answer...
