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I have been given a free motorcycle, a '92 Nighthawk 750 exactly like the one I currently ride. The rub? This bike has 90k miles, yes, 90,000 miles and the top end is apart. Other than that it is a complete motorcycle.

The Nighthawks run a long, long long time with proper care, it is not uncommon to get WAY more than 100k miles from one of them. The thing that finally wears out is usually the cam chain and most folks don't want to split the cases to replace it.

The nice fellow who gave me the bike was in the middle of a move and just didn't have the time to put the bike together again. He's no mechanic but he was very careful with the disassembly and every single part is bagged and tagged. The bike came apart because he *thought* he heard the cam chain rattling. So he did a compression check and one of the plug threads stripped. I don't think there was a compression problem, and if the threads stripped then the results weren't any good anyway. He had bought a complete used head instead of fixing the stripped threads, I have that head. I even have a gasket set. I don't know if he heard normal engine noise, or if the cam chain is actually worn out. How to tell?

I can't find the service limits for the cam chain anywear in the Honda manuals or in Clymer, the tensioner looks great and there is noticeable but not scary-looking wear on the runner pads for the tensioner. The rest of what I can see is spectacular. The cams look new, the cylinders are well within spec, the lifters and rockers and all that have NO signs of wear, the pistons look great with the milling marks still intact all the way around the skirt. I'm sure they're in spec.

Extra money is hard to get for me these days. There's no way I can put in a new cam chain. I'd like to reassembe the bike and run it. Fresh rings for all four pistons will cost about $150, more than I can spend on this old bike.

Here's my question: What would happen if I didn't put in new rings and ran the old ones? If I can figure out the hydraulic valves, I can do this entire job myself and have a running motorcycle.

Oh, one more question: I have heard that you can put a master link on a new cam chain and avoid splitting the cases. Is this true and can the home shadetree mechanic do it? I see on Ebay a new cam chain for this Nighthawk that comes with a master link.

I appreciate any help very much...

Nobody?

If you can buy a cam chain with a master link, without breaking the bank, I say do it. It be a shame to have to tear it down to replace that chain in the next couple of years when you have it apart now.

Agreed with JohnJ but if you leave it alone you shouldn't need to do the rings unless they're frozen in the cylinders. As long as you don't take off the cylinder heads you should be fine.

Thanks ya'll.


Well, the cylinder head is definately off the bike. Since the threads on the plug holes were damaged the head was removed. I'm really not quite sure why the fellow took off the cylinders too. Each piston is in its own numbered bag, and the rings are all free and they all look good.

This bike runs the type of cam chain that looks like triple links, the HI-VO or whatever. It's not the roller chain type. Looks like I can replace it with the roller ring type with a master link for about $60, does that sound right? Who makes aftermarket cam chains?

Rings have a slight taper to the edge that contacts the cylinder walls. Rings with good life left will show a shiny wear pattern near the bottom edge of the ring and a dark, un-worn area around the top edge. If the entire sealing surface is worn and shiny, the rings may still seal and work fine, but they are approaching the end of their life cycle.

Hope that made sense.....

Yes, it does, thank you. I didn't know that. Will be checking it tonight....

Wow, there *is* a dark ring, very very very narrow, at the top of all the rings on all four pistons! Maybe I don't need rings after all!

The rings are probably good enough to re-use..... I can't think of any good reason for you not to use them.

....but just to alleviate that comfortable feeling you now have

.... as a mechanic I have put used rings in all kinds of engines over the years, and they have all ran afterwards, but it is never something I have been comfortable with or would choose to do on my own equipment. Just on principle if nothing else.

That said.... for a spare motor or one I was selling, I wouldn't have a big problem with it. If it was something I depended on for daily transport or to haul my azz across the country or into the backwoods or such, those rings would eat at my feeble mind the entire time the engine ran. (so would the used bearings, oil pump and everything else in that motor, but I'm like that... )

I understand how economics and circumstances can affect such decisions, and we all have to take those things into consideration, but I'm paranoid and on my own if things go sideways. I'll error on the side of getting my sorryass home that night, because ain't nobody I can call to come get me and I will only walk so far by choice. (and not too very far at that)

Dang. Pi$$ed all in my Cheerios, didn't you?




Well you have a valid point. Dunno about the rings, really don't want to drop that much dough on it.

But definately the cam chain Buzz and Wrider?