Topic: Only 8k miles on my 73 750... yeah right.

[Drew]

Well I just joined up today and this is my first post.  Bought a 73 750 about 4 months ago.  Got it running and have been cruising around for a bit but now its time to tear it down to build it back up.  The odometer says that the bike only has 8k miles on it but I just feel that's to good to be true (especially considering the condition the bike is in).  Does anyone have a technique that they use to determine if the odometer was tampered with or any other ways of "reading" an old bike for wear that would indicate this low of miles could not be possible?  Any suggestions would be very helpful.

Thanks!

[ftwaynegordo]

I suppose someone could have replaced the speedo unit with a new one, which would only show you miles that were racked up while on that speedo, but I don't know of a way to see if the speedo could be tampered with. Sorry.

[Gordon]

Not a whole lot to gain by tampering with the odometer on a 750K3.  Anything's possible, but the more likely possibilities are it's the original mileage, it's a replacement speedometer as previously mentioned, or it was run without a speedo cable. 

Looks can be deceiving.  A low-mile bike left out in the elements will look like it's been through the wringer. 

[dave500]

real sloppy swingarm bushes might be something that shows true milage,stone chips on the frame?real scored rims from having a few sets of tyres fitted maybe?how worn does the actual rear brake pedal look where your boot might rub it?

[MCRider]

Yeah, even if it was only 8,000 miles I wouldn't be too thrilled. Unless it was stored in a climate controlled space, and sprayed down with WD or the like, Every single movable part and piece of rubber is trashed, corroded, rusted, hardened or otherwise in need of service or most likely replacement. Like cables, tires, brakes, chain, etc. Except the engine should still be in good shape, though the valve guide seals are hard as rocks and it will smoke like a chimney. If it were only 10 years old and still had 10 years of life in the aforementioned parts, then only 8,000 miles would mean something. But at 38 years, well....
You say you'e getting ready to tear it down? That's the best thing. and the engine will be in good shape whether 8,000 or 38,000 (except the guide seals.) 

How's that for a buzz kill?  Have fun.

PS: The swingarm may not have much play in it. And that could be a good clue. Or it may just be so rusted up inside the bushings can't move anyway.

[Gordon]

A higher mileage bike with stock steering head bearings may very likely have an indentation in the races that causes the front end to favor the middle position.  This is easy to check with the front tire off the ground. 

Of course, a lower mileage bike that has been run exclusively on terrible roads or that has been wheelied on a regular basis may also have this issue. 

[Drew]

Wow I can tell this site will be very helpful.  Thanks for all the comments.  I guess the reason I am curious about the accuracy of the mileage is to help determine if I should replace the bottom end parts such as chains, seals, bearings. 

[Gordon]

Wow I can tell this site will be very helpful.  Thanks for all the comments.  I guess the reason I am curious about the accuracy of the mileage is to help determine if I should replace the bottom end parts such as chains, seals, bearings.

The bottom end is almost bullet proof. 

[greenjeans]

Lots of parts have torq paint dabs from the factory - yellow.     Parts that got changed out may have lost them.

My 75 has 10k - I believe it after seeing the oilpan, wheel bearing retainers and other misc places....   however, it looks like it has 100,000

Little things like the airbox rubber boots - they should be more pliable vs those with high mileage.

On the guages, I'm pretty sure the only way to get those apart to tamper with them is to break the trim ring that holds them together.
But - that doesn't mean that thye didn't run for a decade without speedometer cables.

[MCRider]

Wow I can tell this site will be very helpful.  Thanks for all the comments.  I guess the reason I am curious about the accuracy of the mileage is to help determine if I should replace the bottom end parts such as chains, seals, bearings.

The bottom end should be fine unless you have clues to abuse, jumping out of gear especially. There is a protocol for measuring primary chain wear. Yours will pass. If it ain't leaking now the seals are fine. The bearings are nearly eternal.

Depending what you want to end up with, I'd take the head off to replace the valve guide seals, otherwise leave the engine alone. Unless you want a hotrod.

Concentrate on the chassis for reasons already discussed.

To your original question, many here including me, have taken speedos apart. A good shop could do it without you ever knowing, but a shop likely wouldn't turn it back for fear of the law.

If anything it went sans cable for a while.

[Drew]

Sounds like I shouldn't worry about the bottom end.  I hope to start a build thread in the project shop forum soon.

Thanks!

[ekpent]

Welcome.  Toss us a bone and post a pic of it as it is now.We all like the pics.

[octagon]

you could pull the primary sprocket cover and look at the bullet connectors and wiring coming off the alternator. if it's very stiff and the connectors are very hard to pull apart that points towards higher mileage. if you really have 8000 miles they should be in pretty good shape. not a bad idea to clean those connectors anyway.
the sprocket itself should look pretty good with that low mileage. but i just saw one with only 10 thousand on it and the teeth were worn irregularly. so maybe you can't count on the sprocket condition as an indicator.

[Grabcon]

So I will be the knuckle head that asks the $64 question. If it running good and sounds good why would you tear the motor down? Sounds like a lot of work that may not need to be done. These motors are rock solid and can easily go 50 to 100k. I just bought a barn bike this winter with 20k on it and a motor tear down is the furthest thing from my mind. Run it and drive it. Used motors are cheap.

[Drew]

I just posted some pics on the project shop thread so take a look!  It may not look like much but this bike is awesome.

[greenjeans]

So I will be the knuckle head that asks the $64 question. If it running good and sounds good why would you tear the motor down? Sounds like a lot of work that may not need to be done. These motors are rock solid and can easily go 50 to 100k. I just bought a barn bike this winter with 20k on it and a motor tear down is the furthest thing from my mind. Run it and drive it. Used motors are cheap.

With these 750s I usually just do routine maintenance and clean the carbs twice and ride the bike for a month or so before I even consider a rebuild.   In that time you can generally tell if you "really" need to tear it down.   

If it ain't broke, don't fix it....

[Duke McDukiedook]

I don't get it either, why tear down a perfect runner that may weep a little bit of oil?

I guess if I smoked up all my meth I might be looking for something to do on the fifth consecutive night of zero sleep after I dismantled all the other appliances in the house.