bike died on way home....but now won't fire up!

Hi Guys

So here is my story, I've had 1982 yam xj650rj for a year now and rebuilt most of it. Things I've done in the last month;

Valves checked changed 7/8
Bench sync
Replaced throttle shaft seals
replaced 1 diapram
Given carbs a good clean
used tiny drill bit from chacal to clean enrichment curcuit
new clear inline filter

So I finally get the bike going, but died in town the other day. I spected the carbs again and found the emulsion tubes gunked up and other passgage ways, after a clean she fired up, I rode her home but Died on me 4 times, again I used choke to get me home, decided to check float levels and found they were all were out, although they were dry set at 17.5mm, I could only alter the far outside carb float as I couldn't un do the screws on the others, so I tried to start her up and would run on choke only and die if I turned the choke off, now she will crank over but not start, I fear I have either drained the battery or flooded her, I'll recharge the battery and check plugs. Oh and the clear filter is working cos I can see fuel going through both on prime and on, plus it doesn't make a difference if I switch to prime when shes running.
Can anyone shed new light on this problem

Thanks
Daz

 

Possibly sounds like you picked up a tank full of bad Petrol.
While you are charging it, and have the plugs out, you can wind the motor over (IGN dis-connected) to air-out the motor.

The carb drain screws and the spark plugs aretop of the list places to use some anti-seize goop.

 

It's possible to saturate your spark plugs with gasoline to the point that they will not spark any more.

Fully charge the battery and install a set of brand new correctly gapped plugs.

You're going to have to solve the drain screw issue at some point to be able to properly adjust the floats.

 

You can also burn plugs clean with a lighter or torch.
But Fitz is right- - sometimes plugs will foul and not look that bad.

 

Thanks I'll to it tomorrow....oh and by the way I have the brand new carb drain screws [from chacal]. thats not the problem, I'm having problems with getting the allen hean bolts off that hold the bowls on...gonna have to shorten an allen head key to be able to get in to the tight spots.........or sort the floats off the bike!.

Thanks

Daz

 

Thanks i'll do that...ps I thought that a new set of plugs will have the right gap already...or do I not assume that and check them when they come!

Daz

 

Thanks i'll do that...ps I thought that a new set of plugs will have the right gap already...or do I not assume that and check them when they come!

Daz

 

Actually, most plugs come with a .032 gap, or a little larger, and the XJ series seems to like a .027 gap. Doesn't sound like much difference, but these bikes are finicky cats !

 

For most XJs (including yours Dazsculpt) 0.028-0.032" (0.7-0.8mm) plug gap is recommended. I run mine at 0.030 and have had no troubles in my area of the globe. Remember a dab of anti-seize on the threads and torque to 14.5 ft/lbs.
Never, ever trust a plug out of the box to have the gap correct. Big myth that is. And I'll second Time, these bikes are picky about the gap.

 

And now the bad news, you gotta pull the rack, clean them, set the float hieghts (using gas), bench sync' & vac' sync' when back on the bike = happy motoring. 8)

 

Hi

The fuel in the tank has been sitting in the tank for a few months, started up etc a few times but mainly sat, should I ditch the petrol and start a fresh?

Do you know what the shelf life of petrol is sitting in your tank

Daz

 

Fuel left sitting around will at some point become gunk.
Completely drain the tank......... off the bike, it might be a
good idea to pull off the petcock/ tower filter and check their
conditions as well.
Even before all that take off the oil fill cap and give a sniff
just to eliminate that fuel is in the crankcase.
I had similar symtoms last sping and figured out that the
fuel tower came off in the tank and somehow by-passed
the vacuum and went straight to pime fludding the motor
when the bike sat.

 

There's no sense in fighting with bad fuel. A simple siphon will get 95% out of the tank, the hose at the bottom sucking up debris and any water, the leftover 5% of old gas will blend with the new.

The old gas goes in the wife's car.
Since gasoline is a blend of molecules of different weights and boiling points, the lighter ones evaporate off in a couple months. These are the ones that easily create the vapors that start a cold motor.