Oldarmybiker

Right! The bike is now at the dealer and they have raised the issue with Honda. We'll see how that goes in due course. Before it went in I showed them the cover and they agreed to have another look. I then did a couple of oil changes, the first with the PRV removed so that oil could return directly into the crankcase. After running the bike briefly and then opening it up the filter was soaking and the housing full to the brim. So I know the oil pump is working. The second with a new filter and the PRV back in. I took a contiguous video of the following inspection which was, as before, a bone dry filter and housing. Clearly there is a blockage after the PRV, stopping any oil feed to the bottom and top ends. A shortened clip is attached here. No it's not as it seems that mp4 is not acceptable, Sorry. Is it possible to get videos on here?

Evenin' all. A picture paints a thousand words! I have annotated this one for those who are maybe not familiar with the engine. As this is a significant and unarguable defect that has totally compromised the lubrication system, I am looking to a new engine.

Thanks for that jrshunt, especially for the potential offer. I worked in the business for a few years in between two army careers and am under no illusions this is going to require diplomacy, determination and effort. Fortunately I am retired and have the inclination so will be getting lots of ducks in a row before getting the ball rolling. I will keep this post updated as to the progress, trials an tribulations of my journey.

Hello lemur and everybody. Sorry, I was talking cobblers about the main bearings! Just looked at my parts diagrams and all bearings in the motor look to be rollers as you have pointed out. Not sure what I was looking at or thinking to come up with shells. That would explain why the bottom end at least has soldiered on! lemur, if you need the complete parts diagrams I can happily send you the .pdf

I have got to the bottom of the problem! There is a manufacturing defect in the cover where an oil way has not been fully drilled through between the PRV (seen with circlip in previous photos) and the oil ways which go to the crankshaft and back into the crankcase. The latter is the untapped middle hole that can be seen in the top right photo and, judging from its location at the front end of the barrel, probably provides the oil supply to the top end. Effectively, the oil filter exit has been blanked off and not allowing any oil through. I cannot see the lubrication system being a 'bypass' one if oil is to be fed, at pressure, to the crankshaft and top end. Therefore, there has been no direct oil feed to the crank and top end from the first turn of the motor! Yuuurk! The main bearings are shells so will suffer badly from a lack of any oil supply. Not sure why the engine has not protested yet? Any ideas?

Jrsunt, thanks for that advice. Not naming anyone at this time. lemur, oil strainer always been clean each oil change I have done and the dealer said it was clear also.

Hi jrsunt. The first service I did the filter was bright yellow and dry and the oil was discoloured. The dealer put in a new filter (but a hi-flo by the look of it) and said they changed the oil too before running and opening it up again to check. After Devon the oil was pretty dark but the filter (brown paper with wire mesh) was dry and leaving it on a piece of tissue for 20 minutes left no sign. There was a dribble of oil in the bottom of the filter chamber which was clearly cleaner than what came out of the sump. See my last post to Konrad regarding my thoughts on the crank oil feed. Is that right, do you know?

Konrad, That's what I have always understood, which is why I am confused by the oil coming from the main crankcase orifice into the filter chamber and then out into the crankcase casing via the filter retaining cover. If it is a full flow system then that filtered oil should be making it's way to the big end et al somehow. Now it occurs to me that an oilway in the cover takes the oil to the roller bearing and oil seal in the crankcase cover allowing pressurised oil through the crankshaft to the mains and big end? That would be very worrying as it would mean no oil making it's way to where it is needed etc.. Though if that were the case they would have gone by now! I am going to have a better nose around tomorrow. Cheers

Hi jrsunt, Your post implies that the flywheel axle has an oil way leading to or from the crank big end housing? Do you know which way the oil flows? Also, I would think that the oil filter chamber should be full of flowing hot oil during operation and any grease on the spring would be quickly dissolved into the main oil volume?

Hello Konrad, thanks for responding. First service is due at 500 Km (312 m) and subsequently at 1000 Km intervals, so I was ahead of it a little at 259 m. The filter would be difficult, if not impossible, to fit the wrong way round, so no issue there. I covered around 400 miles after the dealer said no problems. I would expect the filter element to be swollen and discoloured after this, which it was not. Also, the outflow/exit from the filter chamber is an orifice in the centre of the sealed filter retaining plate, so it cannot drain down over time. Therefore, on removal the chamber should be a bit less than half full, yet there was just a dribble lying in the bottom. Probably what the dealer saw and took to be adequate, if indeed they ever did look? Clearly oil is circulating around the motor, otherwise it would have gone terminal by now, as you rightly point out. The more I think about it, I am pretty sure it is a bypass system as any exit that is, or should be, in the crankcase cover can only deposit oil back into the main chamber and sump. I don't know what the design proportion of oil to go through the filter is (10% ?), but there has been no filtering at all up to this point in time. Probably not the end of the world, as you say. However, I think my next move is to remove and check the PRV which should be controlling the oil flow rate. Maybe it is defective?

Hello. I bought a brand new 4 Ride in April last. Ran it in for 260 miles before servicing it prior to a weekend trail riding in N Wales. The oil filter was bone dry with a dribble of oil sitting inside the filter housing. Aaaargh! Fortunately I still had my old CRF for the weekend and the 4 Ride went into the dealer a couple of days later. They said that there was no issue that they could find as they replaced the filter, ran the bike and opened it up again to find oil as they would expect to see. Vaguely reassured, I took it to France for three days trail riding and then to Devon in December, nearly 400 miles. Took it apart for an oil service and found a dry filter again! Even the grease on the filter to hold the spring in place was still there. Having broken my front mudguard in France I was sourcing a replacement and found myself talking to Gordon at Mickey Oates in Glasgow. He was very helpful and forthcoming so I told him about the oil issue. He told me that they had seen this problem before due to a blocked/ incomplete oil way in the crankcase cover and that Honda had replaced them. He kindly offered to send me photos he had to help identify the correct holes to pour oil into and check that it flowed through. Well, Xmas was upon us and I am only now getting around to checking it out. Unfortunately I did not get the photos because Mickey Oates closed it's doors for good not long after I called (sorry guys) and are now not available to help. Looking at the exploded parts diagrams and the actual crankcase I am assuming the duff oil way would be in the area of the pressure relief valve, which looks to be after the oil filter in terms of the flow direction. There is no obvious exit point for oil anywhere near the PRV so maybe this is the problem? I cannot ascertain if the oil system is a 'total flow' or 'bypass' one. Therefore, can anybody help with the following before I go out to bat against Honda: 1. Anyone else experienced this? 2. Is the system total flow or bypass? 3. Even if the system is a bypass one, no filtration will have been taking place. How concerned do I need to be about damage/wear up to this point? Any feedback appreciated