OK. So I need a top end gasket set for my FireBlade (CBR900RRN). Simple you may say, just ring up Mister Honda/trawl Ebay/whatever and hand over some money. Job done. Well .... nope. My bike was tuned a few years back and it now sits at c. 925cc (from the original 893cc). This was done by using the largest oversize pistons for a 918cc engine (with other changes now 130bhp at the rear wheel). As it was done so long ago (and the tuner has since passed away) I'm not sure which gaskets were used. I'm assuming he used the head gasket for the 918 engine with the rest being for the 893 engine.

Now I know the gasket sets for the two engines have different part numbers but wondered whether the difference was just a different head gasket or are there other differences? My memory has faded as to what exactly changed between the two engines so I'm throwing the query out to the wider cbr forum for advice. I guess I'm really asking if I bought top end gasket set for the 918 engine specifically for the head gasket would the rest of the bits fit my 893-based engine?

Ta

 

Hmm, that is a good question. One in which I have no idea. But hopefully someone on here will be able to provide some insight.

 

OK. Thought someone might already have done the legwork and could say 'yay' or 'nay' but obviously not. So I went through the parts manual and checked part numbers myself for all 'o' rings and gaskets on the cylinder block and upwards. Seems the head gasket is different (obviously) but just about everything else is the same. EXCEPT the inlet guide oil seals. The RRN (92 for those in the US - not sure you got it) and the rest of the 893 engines have a part number of 12209-ML0-722. The RRT/RRV (96/97) 918 engines have inlet guide oil seal with a part number of 12209-MZ5-003. Not sure what the difference is as the part numbers for everything else to do with the inlet valves is the same for 893 and 918 engines as far as I can tell.

I have seen 3rd parties selling seals with the same (their own) part numbers for all years and I've contacted one via email to see what they say. No reply as yet but it is the weekend. But does anyone here know why the difference in part numbers? If I can get a definitive 'yes the later oil seals fit the earlier engine' then my choice of gasket kit is easy.

Thanks.

 

Geez. All I need is an answer to 'will the later (RRT) valve guide oil seals fit the earlier (RRN) engine'?

Tried an online non-OEM store (won't mention the name) but got 'can't find those part numbers on our system'. Of course not, they're Honda part numbers and you need to cross-reference them!!!!

Tried emailing a Honda dealers with a large-ish online presence. Just got '...They are both in stock too. So, I am not sure if they will cross fit the engines'. That's because you haven't checked!!

So, tried Honda directly (in the UK) with an email and got this 'We would recommend discussing the matter further with our qualified technicians based within the Honda dealership network. They will be best-equipped to advise on the compatibility of the parts mentioned with your Honda CBR900RR, as well as any other technical queries you might have'. Sort of OK then, sounds plausible. I'll give it a go.

Tried ringing my local Honda dealer and got a 'we can check part numbers but no way can we tell if different part numbers will fit different engines'. Right, just what I thought. So back to Honda UK. And got his 'Technical queries are handled by our dealerships, as they have the technical knowledge to handle them. Furthermore, they are able to raise requests to our Technical teams for assistance with queries they are unable to resolve. We would suggest reaching out to a Honda dealership for further assistance. If the dealership you originally consulted with wasn't able to assist, you could try an alternative dealership'.

F**k me! I'm sure a dealer will go to a 'technical team' at Honda UK, so why not cut out the middle man and do it yourself?? Not sure what it's like in other parts of the world but in the UK customer service seems to have disappeared down the pan!

And breathe .................................................. ...

So, anybody know (based on the above question and the fact that all other parts of the inlet valve/cam have identical part numbers between engines)? I'm assuming they will fit but it would be nice to know for sure as Honda said the seals (from them) are about £12 each - 8 needed...

Alternatively, someplace to go to try to get the answer?

Ta.

 

So I finally got an answer from Kibblewhite who aren't sure, like me, why Honda changed part numbers (could be a vendor change, material change, or some other design change) but that they supply the same parts for the 893 AND 918 engines, so I'm happy that the later Honda parts would fit the earlier engine. As they actually read my query and looked into it I'll be going to them for the valve guide oil seals.

Hope that helps someone else.

 

Result, finally found someone who knew what they were talking about. As you have found out a rarity these days