After tearing down my F3 motor due to a "popping out" 2nd gear, I got a opinion from a shop as to what gears looked most in need of replacing. Of couse they pointed out all the wear on the all the gear dogs/slots, and hence implied most of it should be replaced. Rather than replace all the gears (my budget is not excited about that), the route they insisted on was to send the tranny shafts and gears out to a specific performance shop and get them procut? or angle cut?, I cant remember the exact term at the moment. The service guy implied the gears are less likely to miss shift from this type of machining, and other shop people chime in on how they had it done, and another claimed that its the first thing he would do to a new bike.Anyone have any experience with specialty transmission work like this? Is this something that is durable for a street bike? Any opinions? thanks in advance.

 

The advice you got sounds about as good as using wd-40 for engine-oil.......

My suggestion? Replace all of the worn out gears and ride on.

Honda did right the first time, no back-woods hillbilly with an angle grinder is going to make it better than the jap engineers....................

 

Back cut gears are common...I wouldn't let anyone do it that isn't specialized for it...angles need to be precise, and surface finishes be good with a radius as the base of the cut.

The angle they put on them is slight...only a few degree's. I think Falicon does it, so does APE, but I am sure there are others.

I have a couple buddies that drag race, and back cutting (angle cutting) theengagement "dogs" isalmost a requirement for them.

All that said, I would do whats cheapest for you.

I've got an F3 tranny from an engine that dropped a valve....I can dig it out of my spares box.

 

That kind of custom tranny work won't be worth the expense unless you are racing.

 

I would agree....normally its a racing modification, and even then its rarely done. It might be the cheapest alternative to get his bike back on the road though...

Back cutting is $300...but APE is kind of a pricey shop...I am sure a little looking will find it for $200-250. They will also just do 2nd for about $100- which I think a lot of bikes could use....I know my zx6r could.
http://www.aperaceparts.com/transmissions.html

Gears are NOT cheap...wow...that will get painful fast.
http://houseofmotorcycles.bikebandit...e~CBR600F3.asp

That said...a used F3 engine isn't that pricey either....and the remainders of your engine are worth something too.

How 'bout you push the bike off a trailer, get the insurance money and buy a different one...?

"Sir, can you explain how the engine came out and fell apart just from falling off your trailer?"....uuuhhhh....

 

LOL

Yeah...wish I had full coverage on my bike when it got stolen. Thought I was lucky when I found it a few weeks later... now elbows deep into this fix-it project. Learning as I go.

So back cuttingWORN gears is not unheard of? I wondering if I am asking for more trouble since there is now less gear material...andthefresh cutpart of the gear probably isn't hardened for wear.

Thanks for all the feedback so far everyone!

 

Transmissions for F3 pop up on ebay often. There is an F2transmissionon eBay for a really good price (at the moment). As of now, it has 1 bid and is at $9.99. I don't know the compatibility, but it is worth looking into. Maybe someone on here knows the answer?

http://cgi.ebay.com/ebaymotors/Honda...spagenameZWDVW

 

There is some thresh hold to doing this on worn gears.If you catch it soon enough you can do this....but I suspect most people just replace gears. I had an early FZR600 and the corners of those dogs were chipped away, and the faces were pounded down....there's no fixing that...you replace them.

With the advent of ebay and forums like this, such stuff as a used tranny is easy to find...and certainly will go cheap....

Indeed, the surface hardness of a gear is is probably 56 Rc...and probaly .030 deep given the pitch of the teeth....so you do cut some of that away...but its probably a forging from 5620 steel(which is strong as **** to begin with).I think the picture isexagerated for clarity....it only takes a couple degrees of undercut to hold them in....my buddy did this to his zx9 tranny to drag race and it was very very subtle. You have threeor more of those big teeth inengagement....verus the gear mesh, with probably a contact ratio of 2....the gear tooth is still the weak link.