1984 FJ/YX600

Every XJ is a project whether big or small. Tell us about yours.
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kiwi5000
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Motorcycles Owned Currently: 1986 Yamaha Radian FJ
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Fri Jul 21, 2017 11:28 am

So I purchased this project bike for the sake of learning how to work on a bike and not feel like if i screw it up then it's not a big deal. This is my 1984 FJ600 with a 1986 YX600 motor or frankenbike as I like to call it. I've sorted out some of the wiring (some of it's still finicky though) and was able to get it to kick over but now I'm at a stand still. New plugs. Changed the oil and filter. I sprayed the carbs with cleaner but not entirely sure it's 100% so I might just buy all new jets and take it apart and soak it. Before I go further though I'd like to share my troubles with anyone who could help.

1.) After testing the spark, there was a residual power surge. Yeah I got a little shock. I did it again (without holding it) and saw a residual spark. Like it's hold the current temporary then letting it go. Is that normal?
2.) An odd thing happened when i was turning it over after I let go of the switch it kept turning! I pushed the kill switch and shut the ignition off but it was still turning over! Is that normal? Ok, I know it's not normal but what's the deal with that? It was scary.
3.) It backfires out the muffler when I turn it over. Occasionally. Someone told me it was timing and I've ordered an ignition box just to test that. I'm leaning towards the carbs.
4.) When I turn it over one of the carbs looks like it's shooting out the gas. Like a mist. What could cause that?

That's all for now. I'm just trying to get it running and it's fighting me somethin fierce. Thank you for your time. I'll be updating this when I can.

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Crimson
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Fri Jul 21, 2017 11:51 am

2.) An odd thing happened when i was turning it over after I let go of the switch it kept turning! I pushed the kill switch and shut the ignition off but it was still turning over! Is that normal? Ok, I know it's not normal but what's the deal with that? It was scary.
Just wanted to say, don't use the bike until you've sorted the problem out as you risk destroying your starter motor and possibly your starter gears. You should check the wiring to the ignition switch, and the switch itself (it might not be returning properly). The problem is almost certain to be electrical.
I'm sure you'll sort out all the other problems soon, but watch out with that one. Turning the starter motor should be a momentary thing.
A record of maintenance items carried out on my bike:
https://crimsonxj.wordpress.com/

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kiwi5000
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Motorcycles Owned Currently: 1986 Yamaha Radian FJ
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Fri Aug 25, 2017 4:45 am

So here's an update to my project.

lapped and adjusted the valves.
Deglazed the cylinder
Cleaned and replaced the carb jets and float needle.
Cleaned and replaced brake caliper rings.
New battery.
New oil filter and oil.

Carbs are bit of trouble right now so I'm gonna take them apart and replace the o-rings where they connect together then adjust the float height again.

There's gas in the air filters so I think they're leaking through or the float height is wrong or something. That's my next on the todo list.

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MrSam
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Motorcycles Owned Currently: 1988 Yamaha XJ600 & 2016 Yamaha XSR700

Tue Sep 05, 2017 8:46 pm

Hi Kiwi

How did you get on with this?
Another thing to check would be your pilot screws if you haven't already. They should all be set at 2 turns out (factory) i'd go 2 and a half for a start.
By the sounds of it you are the type of person that wants your bike to run 100 percent. Ditch the pod filters and get a standard air box or you will be chasing dreams... thank me later.
It's about the journey not the destination.

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kiwi5000
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Motorcycles Owned Currently: 1986 Yamaha Radian FJ
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Thu Sep 07, 2017 12:18 pm

MrSam - I'm sooooo close! Here's the ups and downs so far.

Brakes - introducing the fluid took so long I thought i was doing it wrong but i think the front brakes are done.Yesterday I noticed some fluid around the sight glass so I've ordered the replacement glass and o-ring. I don't want to take it off again so I'll try and replace it on the bike. We'll see how that goes. Need to finish the back brakes tonight. I took apart the hydraulics and cleaned it and it's actually in decent shape.

Engine - I noticed some oil leaking from the top and apparently i didn't have the rubber seal on correctly. Fixed in and went to put the cover on and what doya know... stripped the screw. I'm gonna blame the PO on that one ;) ordered a helicoil kit M6 which took a lifetime to get here. First time using it and it worked out good. Went to put the cover on and guess what? Stripped anther one, I mean the PO must have done that too right?! So again, off the cover went and easy peasy with the helicoil. FINALLY go it nipped up without another strip.

Gas - after that glorious first time engine start I noticed gas leaking from the carbs. My homemade gaskets did not work so I made some more! I made a little punch too that got the holes out much easier than an exacto. This time I used some fuel resistant gasket dressing. Permitex... it's blue and gooey. Separated them and examined the o-rings. $5 for one new o-ring, no thanks. Soaked the old ones in my rubber re-newer along with the center T connector. Came out like new...ish. Adjusted the float level, left gas in it overnight and no leaks! Gonna slap it back on tonight and give it another go.

Air - Yeah, i've now researched a bit more on those pods and they're not exactly plug and play but that's all I've got right now so I'll adjust the amount of air that goes in and hope for the best. I wonder what the PO did? While i've got the carbs off i'm gonna make a template and try and make an air box myself. Idk, something. In the haynes manual it does not specify how many turns for the Radian so when i put the new pilot screw in I did 2.5 turns out.

Electronics - Ordered used left and right controllers. Haven't tested them yet but they look good and complete. Replaced the starter relay too which is strange because that was a new one i just put on it. Go figure.

I wish I would have videoed some of this or pictures or something but when I'm working I don't wanna fuss with anything other than my bike. It needs my full attention. I'll do a walk through once it's running and post it. Fingers crossed!

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