Only $800 invested eh... well, most of the time, you can get a replacement engine for $100 - $200 that the used shop will tell you "it came from a running bike". So, yeah, why was the bike brought to your establishment? It's such a hard decision to decide too much invested to just quit. Unless you find that used bike (crashed bike) that really does have very low mileage on the clock, it's hit and miss with replacing the engine, but for the work you're thinking of doing, $200 for a new to you engine - worth the gamble imho.
When to say When
I've been working on my project '79 cx500 for a few months now and I only have a couple free weeks left. Bought it for $200 off a farmer who said it'd been sitting in his barn for 2 years, but it hadn't been registered since '98. I made sure it wasn't seized before I bought it (learned that lesson the hard way on a seadoo).
Before I started spending money on the bike it had to run, I wasn't overhauling the engine. After a basic carb cleaning and fluid change, it ran on one cylinder at about 1100 rpm. The clutch was free so I rode it up the driveway into the garage, where it remains. I've replaced the brake MS, pc'd the tank, replaced the front tire, added the ignitech ignition (b/c I thought the module was preventing one cylinder), and most importantly - completely overhauled the carburetors.
After the carbs were finally done (switched for a, '81 pair), for the 8th time, it would run for 5-10 minutes at a time with the choke on. Yeah, I know it was lean...but no amount of fiddling with the pilot/float/jets/needles/air filter/air leaks/etc would fix it. In fact, I had the pilot at the richest setting that wouldn't kill the bike immediately. This 5-10 run time was the best it'd been, but it would always die b/c the spark plugs would fowl with oil and gas. There was also a considerable amount of white-blue smoke from the left cylinder (nearly none from the right-the heat of the exhaust confirmed that both cylinders were firing). When I drained the oil, it was a little cloudy, thin, but not milky. The coolant still looked new.I pulled the heads (sts) and found only minor slop in the valves. I got new seals, but I'm going to measure the guides and probably not replace them.
Theres the setup, long story
So heres the issue: The RH cylinder (the one that WASN'T smoking) is very pitted. I don't know how to post pictures or I'd show everyone. I can only find one OS +0.25 piston and set of rings online, but I'm afraid it might take more than that.
Can I just go OS on one piston? Can I resleave this cylinder? Should I scrap the engine/bike? I'm already up to $800 on my $500 budget and the person I'm building for decided she'd rather have a vespa (hssss).
Any ideas?
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