The International CBX Owners Association

Got about 500 miles on my restored 79 and it appears to have developed an oil leak around the front sprocket as that is what is on the floor directly underneath there is also some spatter on the rear tire rim probably from this as well how big of a job is it to change out that seal does the whole engine have to come apart or is there another fix?

There is an article in one of the Past CBXpesses that describes the process on how to remove the seal without splitting the cases. You basicly dril a couple pilot holes in the seal and put a couple machine screws in the seal then take a small chisle and collaspe the seal inward toward the primary shaft and pull the seal out. Get a new seal and grind the lip off, clean the case suface with brake cleaner, put some Hondabond on the seal and tap the seal back into the cases.

You can do a search in the past Magazines that Nils archived and read the article.

Good luck.

First make sure it's not the o-ring on the sprocket retaining bolt that's leaking.

Dave

Thanks I'll check the o-ring first then the seal. is the seal and o-ring still available from Honda?

Do I recall that it is possible to swell that seal by adding some kerosene to the crankcase, running it, letting it sit, and then changing the oil? I swear I read that somewhere. Is this a terrible idea?

N.

Wow Nils never heard that before but is a possibility, A horrible thing called work keeps getting in the way of my investigation, I,ll keep you tuned also what oil is recommended for my bike without creating a whole new thread!!!

Yeah, I googled this after posting that and it is indeed a possibility. How long it might last is anyone's guess, but you can find numerous pages on this and other leak-stopper additives, most of which contain kerosene as the main active ingredient added to the motor oil (in place of some of it, to be fine-grained). YMMV, go carefully, but I remembered that this was done to a bike I sold by the new owner when the countershaft seal leaked and he said it worked fine.

N.

Have you confirmed its leaking from the seal? Rebuilt my engine about a month ago and it too has a leak around the countershaft seal. So I prepped to change out the seal (was going to use some PVC pipe and bolt/washer to 'press' the seal back in) however when I REALLY looked for the source it turns out to be from the crankcase halves next to the seal. Guess when I had rebuilt it I didn't use enough Permatx in that area. Your post indicates the engine was recently rebuilt so maybe it has the same issue?

Jeff Bennetts wrote:There is an article in one of the Past CBXpesses that describes the process on how to remove the seal without splitting the cases. You basicly dril a couple pilot holes in the seal and put a couple machine screws in the seal then take a small chisle and collaspe the seal inward toward the primary shaft and pull the seal out. Get a new seal and grind the lip off, clean the case suface with brake cleaner, put some Hondabond on the seal and tap the seal back into the cases.
You can do a search in the past Magazines that Nils archived and read the article.

Good luck.

7 :

Hi Jeff,
Can you tell me where i can get the copy of the article you mentioned above....i'm quite new to the site and am not sure where the archive stuff is....failing that,do you know how i can get the back edition....think i might have a leaky sprocket....not good!

Hi,
I've managed to find the article regards the removal of the front sprocket seal, without splitting the cases.
Can anyone tell me if this works?
Has anyone out there done it this way that can offer any more guidance?
CBX's....you gotta love em !

Well, it's been done with mixed results. Sometimes works, sometimes not. Personally, I would split the cases and do it right, it's not that bad.

Dave

Furthering Dave's comment, you will know that the case halves were sealed properly.

Like you say, doing it right sounds the best way......thanks both.
Now i've checked the manual, i guess apart from the head, the barrels, the pistons leaving the connecting rods hanging....it should allow me to do this......it sounds so easy when you say it like that....Not !.....thanks again.
Mark.

Having said that (above), Mark, if you can verify that the leak is around the seal, I'd, likely, try to replace the seal before having to pull the engine and split cases. Maybe just getting lazy in my old age. But, if it doesn't work -- oh well. You're only out some time and a few $.

I'm with you on that...made me think !