New member needs answers

[daves79x]

These crankcases are very porous and the machining process can leave voids not intended to be there, but are. There are only two studs that obviously go directly into the crankcase, all the rest are intended to be blind.

Dave

[Rick Pope]

[/quote]
I'm jealous Rick is your bike a 78. I'd love to own a 78 original.
[/quote]

I don't recall my serial numbers, and I won't be near the bike until April.

[jetts68]

Hi Dave thanks for the information. Interesting to here you suspect my bike is a 78 production machine. Giving me more reason to go down the original restoration route.

[EMS]

This is not a matter of "suspect" - and Dave didn't "suspect" it. Most 1979 model CBXes were produced in 1978. Actually approximately 20,000 out of a total of 24559 (+41 pre-production units) 1979 units. There were only 2 months of production in 1979 for CB1, 1979 models, January and February.

[daves79x]

Do not let your machinist talk you into a lot of expensive head work. Get all-new exhaust valves and lightly grind the seats until the pitting is gone and the valves will hand-lap correctly. The intakes are usually fine with just a hand lap. Unless a guide is damaged, I wouldn't replace any. Those seats would then need re-cut. The bike will run just fine. Check the bores and pistons for wear and if still within tolerance, just a light hone and re-ring. The bottom end will almost always be fine as-is, but should be checked to be sure.

Dave

[jetts68]

Hi dave thanks for the heads up on the valve train. I haven't got into the head that far just yet. The head and barrel are away being skimmed at present. I'm lucky the engineering shop I use doesn't do engine rebuilds they specialise in high percion aircraft industry work and only do me favours as I'm a friend of the owner. And anything I give them has to be spotlessly clean before they will touch it. Their workmanship is unsurpassable compared the engine rebuild shops around me. I really believe a dirty workshop is a sigh of poor workmanship.

[jetts68]

CBX 1000Z. HI all I have a question relating to my starting motor free spinning. Should the starting motor free spin while the engine is running. When I say free spin I mean the engine is spinning the motor. The starter clutch is working correctly as I can hold the armature of the starter still with the engine running. But once I release it, it will spin up to match engine speed. I can only surmise this would not be good for the starter. At a minimum it would cause excessive wear on the brushes and at high rpm the risk of bearing failure.