Will my engine crack in half?

[CB4ME_imp]

On the first episode of Naked Speed, a custom builder who specializes in Honda restorations acquired a complete basket case of an SOHC Honda 750 engine in a cut up and rusted frame. When he removed the drive sprocket he discovered a cracked case and claims that it was not unheard of that early Honda's throwing a chain could crack cases. Urban myth? Dramatic effect? Total BS?

[the Ferret]

Actually CB4ME I saw that several times on CB 750 that were drag raced or street raced. 1969 Chain technology was not too good and a slightly built 750 could easily out power the stock 530 chain which would snap and as the sprocket is turning counter clockwise as the bike rolls forward the chain follows the sprocket and ends up wadding up under the front counter sprocket hitting the case and punching a hole on it. Quite often ( but not always) they the pieces could be rewelded. If not new cases were in order, and since they were split horizontally instead of vertically like a Brit bike, it required a set of cases.

[Damfino_imp]

Yep, read all the time on the SOHC4 forums about somebody picking up a barn find 750 only to find the case is damaged around the chain sprocket.

[NightRider_imp]

I ain't skeered. Instead of working, I scanned the various forums and entries and it appears the issue is operator error mostly in America. Go figure. Who would have guessed? The fix included going to a different chain. I suspect abusing a four cylinder engine with gobs of torque can be risky, being the intellectual giant that I am, I figured that out by myself and so I ain't skeered of breaking this amazing engine.

[rboe]

I've seen plenty of cracked cranks (aka forum members.... )

[NightRider_imp]

I've seen plenty of cracked cranks (aka forum members.... )

Still you purchased a CB1100 so your endorsement is good enough for me.

[Nortoon_imp]

Having worked on both British and Japanese motorcycles, I found the Japanese horizontally spilt cases much easier to disassemble and re-assemble. Everything sits nicely in the Japanese lower case.

Having things fall free while opening British crank cases can make things hard to re-assemble properly. Wrestling the halves of the British cases together while hoping everything stays in place is also a chore. I was fortunate enough to have both a genuine BSA shop manual and parts list that I imported from England along with all the shop tools. I liked my two BSA Lightnings, but they were more difficult to work on.

We may complain about the service interval between valve adjustments on Japanese motorcycles. But my experience with British motorcycles is that they needed a complete motor overhaul every 10,000 miles.

[the Ferret]

2010 and up chains are not 1969 to 1976 chains. Manufacturers ahve increased the pin, plate and tensile strength tremendously. Doubt anyone has to worry about the chain on their CB 1100 breaking and going thru the cases these days.

[rboe]

Unless you get a reflash........

You have been warned!

[flynrider]

2010 and up chains are not 1969 to 1976 chains. Manufacturers ahve increased the pin, plate and tensile strength tremendously. Doubt anyone has to worry about the chain on their CB 1100 breaking and going thru the cases these days.

As long as you install and maintain it properly. Every chain break incident I've ever seen (including one that cracked the crankcase) was caused by someone botching the master link installation.