Gas powered bikes?

jdog

Shop: Halter's Cycles
Shop Keep
In SLC and saw this on FB marketplace
2016 300 xcw with a ton of extras amd low hours
Valued at 6200 I picked it up for 4200 😁happy new fucking year to me !
Nice 👍 one. Ditch that mirror and add some full coverage hand guards & heated grips.
 

clarkenstein

JORBA Board Member/Chapter Leader
JORBA.ORG
Been picking at this CB now here and there. Pulled the motor out, and the top end is finally off. Every screw or bolt removal has been a project. I’ve had to drill a handful out. The impact driver is getting tons of use.

Got the points plate finally off. That was a multi day project of soaking in penetrating oil and smacking with the dead blow hammer. Tach stuff actually came off easily and was in decent shape.

Here’s what I uncovered when I got the top end off. A muddy beach on top of the pistons.

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And the valves - holy hell:
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I pulled the valves out - I think someone drove it into a lake.
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The grit is like sand. Never seen anything like it. New pistons and rings are on order, so another $52. I’m going to dig deeper into it over the next couple weeks and see how terrible the cylinders are. Hopefully standard size rings bring it into spec. It’s a disaster but so far pretty fun. 50/50 on whether it will run again but I’m still going for it.
 
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clarkenstein

JORBA Board Member/Chapter Leader
JORBA.ORG
Remember when you were young, you’d have that one friend who would always ask, “Wanna see something gross?” Well...

I think this piston is shot, maybe?
5ADD7713-1C17-49D0-8FA5-59A13D38CB95.jpeg

Yet again, I have never seen anything like it. I’m splitting the cases next. Going to clean this thing out - there has to be debris down in the bottom end - and debris in the races on the crankshaft could be even worse than what I’m dealing with here.

One decent discovery - the cylinders are acceptable.
4CCAF31F-5571-4906-BE13-919546AD466D.jpeg
 

clarkenstein

JORBA Board Member/Chapter Leader
JORBA.ORG
After a stupid long day at work (that felt like two days, the morning one day, the afternoon the other) I blew off some steam and went to the garage to fiddle some more. I removed the pistons and split the cases tonight.

That rotten piston took an hour to get off. The circlip was completely seized to the Gudgeon pin (that’s the piece the piston can rotate on). Here’s a diagram for those watching at home:
A6267CE9-1DF9-4981-B23B-F045B5AA9A27.png

With some very carefully placed tools and many deliberate hits with the hammer, it finally gave in and moved. The good piston came off with no issue other than the circlip flying across the garage into oblivion when I popped it out.

The crankcase overall is close to mint. Just need to spend a few hours clearing out sludge and gross crap that is deep in the corners and reassembly begins.
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Patrick

Overthinking the draft from the basement already
Staff member
After a stupid long day at work (that felt like two days, the morning one day, the afternoon the other) I blew off some steam and went to the garage to fiddle some more. I removed the pistons and split the cases tonight.

That rotten piston took an hour to get off. The circlip was completely seized to the Gudgeon pin (that’s the piece the piston can rotate on). Here’s a diagram for those watching at home:
View attachment 149532

With some very carefully placed tools and many deliberate hits with the hammer, it finally gave in and moved. The good piston came off with no issue other than the circlip flying across the garage into oblivion when I popped it out.

The crankcase overall is close to mint. Just need to spend a few hours clearing out sludge and gross crap that is deep in the corners and reassembly begins.
View attachment 149533

not bad - disaster averted! it looks like the last thing that motor did was go swimming.
 

clarkenstein

JORBA Board Member/Chapter Leader
JORBA.ORG
not bad - disaster averted! it looks like the last thing that motor did was go swimming.
I agree. Probably sucked in a bunch of water and silt, stalled, and that was the last the bike saw since the 1980s. I do know since the last time it ran, the rest of its time was spent parked in a field partially under a tarp - that’s what I was told when I bought it. Based on the amount of dead spiders and bugs I’ve pulled off of it, I can confirm that.

Once I get the top end back on I’ll need to lap the valves. I’m out of Prussian Blue so another minor expense (~$6) and trip to Autozone.

I have yet to crack open the starter. My guess is that will need a rebuild - fingers crossed I’m wrong. Then it’s on to carb rebuilds and wire harness reconstruction, both of which I have been conveniently ignoring at this point. Pointless to do them if the motor won’t run anyway, but those new parts are ready and waiting. All part of the process of turning garbage into something good!
 

clarkenstein

JORBA Board Member/Chapter Leader
JORBA.ORG
Been picking away at removing the old gaskets on the cases - a hour here, a hour there. It’s tedious work. A steel razor blade can go right into the aluminum and cut it up, which would mean a permanent spot for an oil leak, so it’s relatively delicate work.

I have been using a mix of WD40, 3M pads, steel wool, blades and brushes to scrape away at this almost 5 decade old asbestos and glue based crap. It’s cemented on and my OCD gets the best of me. I want it perfect with no scrapes in the casings, so I’m doing most by hand vs using power. So far only a couple super small nicks on just the edges in the scraping process so it’s been a win so far. The faces are really shaping up. A few more to go (there’s quite a few) and I can start considering reassembly. If the garage wasn’t so damn cold I would probably be moving faster.
Almost like new (I should have taken a “before”):

E70776EB-BAC2-4BCA-A65B-82A0F564E7A5.jpeg

Yes those are Qtips on the bench. Great to have for those really tough-to-reach corners and weird-shaped spots when pulling out sludge.
 

pkovo

Well-Known Member
That looks great! My XS650 motor has never been opened and I think it leaks from nearly every gasket at this point. I've considered doing this for many years, but I just keep kicking that can down the road instead. Maybe this thread will give me the motivation to actually do it.
 
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