Hi all, new to the forum and have questions already .. I just bought a 2007 RR7 and now wished I hadn’t .. I have had seven or eight RR7’s all Repsols. The woes started immediately with bits that were not outlined when advertised .. I’ve only done 90 miles on it .. riding home from work on Friday, yes it was hot all was well .. pulled off the roundabout exit accelerated hard (as you do) just changed into fourth from almost on the limiter in third gear .. up at around 10,000 rpm the bike felt weird, almost like the rear was locking up, pulled in the clutch (engine remained running) pulled over gave a little rev that’s when the dreaded bottom end rattle started .. I was only 5 minutes from home. After nursing the bike home (oil light flickering on idle) and letting the bike cool I restarted it .. runs perfect, no erratic idle no irregular cranking but around 5K there is a rattle from the bottom end from cold. So I’ve removed the engine and about to strip and investigate .. I’ve never had an engine failure on any bike I have ever owned .. questions … What are the common failures on this motor, There are different bearing classifications available from Honda, I’m assuming oversize etc, can the crank be reworked and if so any recommendations on crank grinding engineering shops in the U.K? Most of the sealing surfaces are gasket free, what’s the best sealer/liquid gasket solution ? If it turns out this was a partial seize and the piston/bores are damaged is there an alternative to stock, maybe different pistons with any BHP Upgrades ? The motor looks pretty easy to work on I especially like the cassette type gearbox are there any issues with the strip and rebuild process ? I am a fully qualified tech of lots of years !!! Any advise and recommendations or general words of wisdom gratefully received.. everyday is a school day .. cheers Colin
By the sound of it you know more about engines than most of us on here. I'm not aware of any common engine faults on the RR4-7 engines as they are pretty bullet proof. It's only the gearbox that can give problems, but like you say, the cassette type makes it easier to work on. One thing I can say is that they are a very popular bike and many will have been written off by now, so replacement engines are out there. Not much to modify on these. There were a few BSB spec engines about, but I've heard that the mounts are different.
Thank you for your reply, so I’ve stripped the engine, number one big end bearing had spun and interestingly main bearings 2 and 3 had worn to the copper, that would have been the point when the rear end started to lockup .. Fortunately after measuring the crank and cleaning up the slight surface marks with some 1500 paper it appears a set of bearings for the mains and big ends plus the bolts (stretch bolts) and a tube of three bond and the engine happily can be rebuilt, I have however ordered a plastigauge kit to double check the clearances .. After lots of research the bearing classification is for tooling and machining tolerances, not oversized bearings (at least not from Honda) so a set of brown big ends and a set of yellow mains it’ll be good to go !! As for replacement used engines .. they are not cheap and there in no way of knowing how good the used replacement might be ? I didn’t get much help from the main dealer with the bearing classification so a bought a Haynes manual for this and the torque settings, all of this information is document well in the manual. Lastly .. this engine is probably the easiest I have worked on, the only issue is the cost of replacement parts, the OEM bearings are sold individually so ten pieces for the mains and eight for the big ends, the bolts all need replacing as they are torque angled, parts cost including new oil filter, oil and coolant, Honda gasket solution is £675 still better than the £1800 for the least expensive used engine I could find ! so far engine removal and then removing the crank has taken 4 hours the rebuild will be more like 10 times that with cleanup/mating surface prep etc. There are a couple of YouTube videos showing this procedure, it can’t be a coincidence that the same bearing failed on those bike too ? The inside of my engine is super clean so it appears that the lack of carbon deposits or burnt oil residue suggests the bike was maintained correctly, so at 22,000 miles are these engines really bullet proof ? Thoughts and comments welcome ! thank you
Any pics of the work , I'm interested . Do you think its been run short of oil at some stage before you got it ?
Hi… I’m not sure but I’ve found lots of pictures of the previous owner on his profile, looks like he liked to ride around on the rear wheel lots !!! This failure is more common than you think and always number 1, I have not gotten around to stripping and measuring the oil pump yet that’ll be next .. I guess I’m lucky as despite the fact the bearing had spun it was still just about intact hence the lack of catastrophic damage to the crank. It’s hard to imagine oil starvation as the oil pickup is right in the base of the sump .. actually the sump holds the oil pick up pipe in place via several stand-off’s in the bottom of the sump. It’s not out if the question to assume the bike has been run low on oil at some point or the bike was lay on its side with the engine running .. however the tip over sensor is fitted and functional ? ultimately I’ll never know .. pictures for reference .. if required I’ll post up more info on the build and repair process ? Cheers
I found 6 of the ten bolts for the main case bolts on E-Bay these are over £10 each got them for £25 !! Need the outer four shorter bolts now and the 8 rod bolts. I also found a set of mains and big end bearings also on E-Bay in Japan another saving of well over £100 so the cost of the build inc sundries will be around £475 … however obviously the labour is free .. I suspect at a dealer the cost of this repair would be cost prohibitive I’m thinking 45 hours for the strip and rebuild inc assessing and measuring the rest of the engine.
