Newbie XJ owner, few questions

Hey, looks like a great forum, I don't know why I couldn't find it a couple of months ago.

Anyways I bought this 80 XJ650G with only 8kmiles, hadn't run in a long time. So I changed the oil, I swear the Haynes manual said it takes 5.? quarts, and I don't see where the filter goes. And after reading/searching here, I know now that the oil should be in the upper part of the window, but how much after draining it?

Did a compression test, 90psi +/- on all, but I did forget to open the throttle (so I will do it again later). New plugs, try to start it and it will only run for about 2-3 seconds and won't stay running. It was kinda backfiring and seemed like the timing was off, or AF ratio was off (it was definitely rich). But it got better pretty quickly and sounds great if the throttle is held open just a hair, but still dies after 6-8 seconds.

Also fuel leaks when turned to reserve, but not when turned to ON, it looks like it is leaking out the bottom of the #2 carb, but I guess it could be running from somewhere else. So new petcock I guess, and clean out carbs? Any gaskets/parts needed to clean the carbs?

Oh yeah the 5.something quarts of oil started to pour out of the airbox, I pulled the breather hose off and got sprayed, and all over the new seat I just bought, I will probably slide right off the thing now, if I ever get it running. I dunno if that was too much oil, or that the petcock is leaking, or both. So what is a good petcock to get?

And how do you get the center stand up? I almost dropped the bike trying to get the thing on the ground. I ended up working on it while it was on the kick stand.

Sorry for all the questions at once, but any help is greatly appreciated.

Thanks, Garrett.

 

Welcome!

Center stand: Hold LH hand grip with your left hand. Get Right hand under seat grab wheel near rear of seat. Push pedal on centerstand down until it contacts ground, rock bike a bit to be sure both legs are in contact with ground. Push down on centerstand pedal like you are trying to push it into ground and using the motorcycle for leverage. Rock a bit to the rear as you do this and it will pop right up.

Fuel valve: If it runs (without engine vacuum) on RES but not when ON then the problem is likely the rubber sealing disc behind the fuel cock. I had the oposite problem - fuel flowed when ON, but stopped on RES. I got a replacement disc from the Yamaha dealer for $8. After emptying the tank remove the two little screws that hold the retainer in place, pull the fuel cock out - disc is behind there. While you're in there pull the valve from the tank and make sure the pick up screen is in place and clean.

You also probably need needles and seats in the carbs and floats adjusted.

Oil: Capacity is cast into the top of the transmission right by the fill hole. If I recall correctly it's 2.7L with filter change, just about 3 quarts.

 

well for one, the bike only takes a little over 2 quarts. So you need to drain that oil. Getting it off the centerstand is easy. Sit on the bike and rock it forward. I usually squeeze the front brake once it rocks off to help keep it from rolling forward too much.

If it has sat for a while, you should probably take the carbs off and give them a good cleaning replacing the gaskets and o-rings. A rebuild kit can be purchased from eBay, or from places such as www.oldbikebarn.com, and www.bikebandit.com.

It also sounds like the petcock needs to be rebuilt. You can also get a kit at the same places mentioned above.

Repeat the compression test with the throttle valves wide open and post back the results.

 

Hi, My new engine is a 80 xj650g, just done an oil change (an filter), it takes 2.7L with filter change (as Micarl correctly says), and 2.3l without changing the filter. Like PghXJ says, drain out some of that oil.

Hope this helps
Lea

 

CGNTSi:

You need too treat yourself to a New Petcock and some New Float Pins and Seats.

Then, you go on attack:
New Fuse Panel
Inline Fuel Filter
With only 8,000 Miles on the Bike ... I'd bet the Alternator Brushes are like new.
But the limited hours and miles on the engine never stopped the clock on the Fuse Panel.
Get rid of it for a New "Blade Type" Fuse Panel.

The amount of Oil you need to put in the bike is STAMPED right on the case next to the Filler Cap.

A good Thumb Rule is to add the New oil and run it a few minutes ... then, add a little bit at a time until the "Air Bubble Line" in the Oil Level Window just goes away. Fill it to the top of the window.

(Then, pre-ride ... you put the bike on the center Stand and eyeball the window ... If its Full ... GO! If there's an air line ... Top UP!.

 

Thanks for all the help guys!

I am going to look for a new petcock and float pins and seats, and rebuild the carbs.

I re did the compression test with tthe throttle open and got:
#1) 136
#2) 149
#3) 138
#4) 142
So much better! I was kinda afraid it needed a rebuild earlier.

No way to get the airbox out of the frame huh? I want to clean all the oil out of it.

Thanks again, Garrett.

 

Just sacrifice a roll of paper towels and celebrate your fine looking compression.