79 Honda xr500 project


Coast to Coast
Alrighty….like I needed another project, but these are fun and I miss the old one.
Pretty sure I mentioned it….I don’t get along with electronics even more than I do carburetors, so I’ll be asking for help! Has spark but won’t fire at all, not even a pop with fuel directly into plug hole. Soooo…need stronger spark?
Other than that it’s pretty Frankensteined. If it runs good I’ll think of what to do lol.
Oooh…..good thought. I’ll be pulling covers to see how stuff looks this week. Maybe tonite if I can bail from work early!
Nothing looked out of place. A bit of wear from the cam chain though.
Anyone know the resistance limits for the statue and pick up? I’ll be looking today at some point..,
A couple of things, that is excessive wear by the cam chain, so you should check the tensioner and slipper. They are both known to break and cause excessive wear. You need to check the aluminum pipe that is between the chain runs in the middle of the worn part since it is a pressurized oil passage and will cause low oil pressure if it has a hole worn through it. You also need to check the balancer chain tension and that the pivoting adjuster is not cracked. Finally, there has been a lot of aluminum from the cam chain wear run through that engine and it doesn't have a filter. Fortunately, the crank case is pretty open to the clutch side so a spray can of brake cleaner can do a pretty good job of flushing it out if the engine is tilted to that side.
If the cam chain is worn out, they can be hard to find. The CBX uses the same chain and I was able to find a very low miles used one.
With the electronic ignition, they are pretty much either spark or no spark. Also, the timing is not adjustable. I wonder if with the loose timing chain if it hasn't jumped cam timing? They also will not start with low compression. When you pull the valve cover off, be very careful backing out the bolts or you will snap them off. If you are careful, you may only pull the threads out with the bolts on 3 or 4 of them. Plan on helicoiling some of them. If it turns out to be a keeper, I would plan on helicoiling most if not all of them. Given the condition of the timing chain and the wear, you could also be looking at a worn out cam and rockers.
I may have some parts laying around if it comes to that, I have built more than a handful of these engines over the years.
Thanks for all that!!! I was thinking definitely a new cam chain and guides, lots to learn now lol. There was a filter actually, I pulled it out to see how nasty it was. The covers had been pulled previously, I’m guessing they cleaned it though, not a lot of sludge in open spaces. Looks like a bigger project now, guess I’ll pull the motor and start looking at parts!
No….I’m terrible lol. Almost have my bench cleared off, then gotta pull the motor and make a stand for it. Hopefully this weekend.
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