Should I baby engine..??

[Steve Swan]

Posted by Techy502x "Guest"

Hello,

I have just joined the group having registered my sandcast here. I have read all the past posts and haven't seen my question before (or didn't find it)

What was the failure mode that caused the destruction of the sandcast cases...and what was the fix? Did Honda implement and inline fix at some point during sandcast production or did that come with the diecast. My engine serial number is 2747.

I am restoring my sandcast to be a casual rider. The engine ran before I tore the bike apart to chrome.... powder coat, etc. so while it is out should I check/replace something in the engine to avoid future problems or just pretty up the externals and go with it Maybe remove the valve cover and oil pan and look inside??

My engineering mind says to tear it apart and my gut feel says to leave it alone, only allow the engine to idle, and never run it over five minutes.

Jim

[elisent]

The chain was the weak point. With a proper chain and adjustment you should have no worries about riding a sandcast as hard as any other 750. Hondas fix was an extra toothe on the front drive sprocket. I'm a gut guy. If it ran allright when you bought it and you plan only limited miles ,leave it alone. I'm sure I'll get some major disagreement on this. Goodluck and have fun. You will be very impressed, as I am, with the knowledge of some of the people on this list. Welcom, Eli

[Steve Swan]

I agree w/ Eli. About the only way any CB750 engine can be killed is, runnng them out of oil, chronic neglect, abuse (continual over-revving.) A year or so ago, i picked up a sandcast engine still in it's frame. Engine stuck from sitting out of doors, used Kroil and tension to the wheel and after about two weeks the engine freed. Put on a set of "mule" carbs, leaned the sump & oil tank, circulated oil though engine & it fired right up. Smoked for a couple minutes, but idled down, quiet & smooth. You can always start the engine, see how it sounds, then ride it and see how it goes.

[Steve Swan]

Posted by Techy502X "Guest"

Thanks for the replies. Was the fix done during the sandcast era or later with the diecasts? I have an early diecast also so inquiring minds want to know. I may have the fix already at least in the diecast..

Jim

[txmudman]

I drive mine, and drive it hard. I replaced the stock chain with a 530H, it is a lot stronger. No problems.