Cylinder replacement 850 T3

[bobra5037]

I’m considering replacing the chrome cylinders on my newly acquired 1977 850 T3. How difficult is it?  I’m not a mechanic but, then again, I’m not completely useless.  Should I attempt to do this or refer it to a professional?  What can go wrong? 😱

Thanks

Rob

[Antietam Classic Cycle]

Here's the assembly process:
https://www.thisoldtractor.com/projects_roy_smith_2013-03-19_install_the_right_piston_and_cylinder.html

You be the judge if it's something that you can handle.

[cliffrod]

What can go wrong?

Soon after I got my V7 Sport in the early 90’s, I “just” replaced the chrome cylinders and pistons to remedy stuck pistons and peeling chrome resulting from a decade plus of dormancy…. within a couple of years, the entire engine needed a full rebuild.  Loose chrome had already taken its toll.  Since the proper full rebuild, the engine has been bulletproof & fantastic.

Maybe my experience is atypical, but I learned my lesson. I’ve got a couple more chrome bore engines here that will probably run as is.  But I will do everything properly the first time this time- full disassembly, inspection, service as needed, etc- not just replace the chrome cylinders & pistons and hope the rest is ok. 

[bobra5037]

I must admit, it I'm in a bit of a quandary over this.  I'm only the second owner of the bike so I know its full history.  18,000 miles on the clock but has spent the last 20 years or so idle in a garage in a very dry climate.  The bike run well and I can't see any obvious blemishes in the cylinders using an endoscope.  The bike is a hobby and will probably do less than 500 miles a year until I'm too old to get my leg over it (maybe not that far away!).  So, do I ignore it and just ride the thing or do I succumb to my anxiety and get the cylinders replaced?  Only I can answer that question but I'd be interested in others experiences.

Thanks

Rob

[cliffrod]

For comparison, my V7 Sport was used/ridden hard between purchase new here in town (Spartanburg, SC) and when it was apparently parked around 1981.  The speedometer showed around 23k or 25k when I got it iirc.  I have no idea how accurately that reflected actual mileage on engine.

You can just swap cylinders and pistons and see how it goes, especially if the original cylinders look great.     It will either be fine or it won’t be.  But if there is already notable chrome loss when you get in there, doing more at that point would make sense.  Your engine has an actual oil filter, which is better than my engine with no filter.

Your bike, your rules. 

[Tkelly]

If you don’t get it done the resale is minuscule.It might run fine for your purposes the question is whether or not to bring it to  long term reliability.

[moto]

Historically, on this site, the rule of thumb has been that not having replaced the chromed cylinders takes $1000 off the value. This is about the cost of buying a Gilardoni or other set of matched Nikasil-coated cylinders and matched pistons/rings and putting them in yourself. The standard question about a newly available bike has been whether it has the Gilardonis, not whether it was completly dismantled to chase chrome particles.

So spending $1000 and doing the job yourself is a good investment that will likely be rewarded accordingly on resale. If you have average mechanical skills for an old motorcycle rider, it is not a difficult job simply to swap the cylinders and pistons. (Consult the relevant parts of the instructions that were cited in the first response.) It is a satisfying project to do that may impress your friends.

On the other hand, there are plenty of other fish in the sea who will buy your bike for about what you paid for it, odds are. Assuming it has no signs of impending doom.