‘82 XJ650 Maxim Bike won’t start after carb cleaning

I posted 2 weeks about this and was directed to follow church of clean. I’ve since then followed it, ordered a new rebuild kit. Did a full tear down and I’ve successfully put it back together. Still having the same issues. Bike cranks but hesitates to start, I’ve also tried starting fluid to no avail. Battery is new, spark plugs are semi new, since the bike started and ran prior to cleaning. I was even able to ride it a couple of times. Anything else I should be doing or should try?

 

Put a multimeter across the battery terminals and press the starter button and measure voltage. It must not drop below 10 volts. If it does the plugs won't spark. I advise this check because it is not starting with starting fluid. New batteries can be faulty.

You can see a spark with plugs out as the starter motor is not working against compression in the cylinders. With plugs in it might not be sparking if the voltage drops.

This might not sort it but it's an easy quick test to do

 

Thanks for this. I will try it and see what it says

 

The right handlebar switch grounds to the handlebar. Make sure you have a good ground there too.

 

just did the test. It reads 6.5 - 7.0 when pressing the starter button. Without pressing the button it reads at 11.8

Does this mean I should get a new battery?

 

Or can I use a jumpstarter?

 

Use a jumpstart off a car battery if you can. Voltage is too low when you are pressing the start button to operate the TCI transistors to start the engine. Charge your bike battery too and do the test again. Don't buy a battery until you are sure you need one. If your new battery is not holding charge something is wrong with it.

 

charged the battery, used a jump starter. Got new spark plugs and added more engine oil since the oil light comes on when cranking. Still won’t start, although it has a stronger crank now than it did before. Any ideas what I’m missing or why it won’t start?

 

Do you have a brass tube on your carburettors that go into the float bowls? There is a jet at the bottom of each bowl that must be clean to allow fuel to travel up the brass tube for cold starting. It looks like this on the BS36 carburettors.




If you have the same carburettors and the float bowl jets are blocked the engine won't start.

 

I do have those brass tubes in the float bowl. I will take them off and clean those tubes again. But I’m positive it’s super clean since I dipped it in chem dip, water rinse and used compressed air to dry it.

 

Make sure the tiny passage in the bowl is clear too!

 

It is not the tubes the tiny jets at the botton of the float bowls too.

 

yes, I’ve installed new jets in the bottom of the bowls. I didn’t take any pics from cleaning but this is the closest I have to showing that the carbs were completely dismantled.

 

You must be getting fuel through for starting from cold then.

 

yes I think so. It just occurred to me that I should prob check if the spark plugs are producing any spark. Maybe that’s the issue.

 

yes, the tiny passage in the bowl was clean when I reassembled it.

 

Check your input voltage to the ignition coils. Do you still have the original Yamaha fusebox? They are notorious for causing electrical problems, better with the blade type fuse box.

 

This is normal, it's a check to test the light bulb while pressing start. Check your oil level in the little glass window on the clutch cover (right side of bike)

 

just checked spark plugs and there is spark. It can’t be the fuse box because it started and ran prior to carb cleaning. I’ll just have to take out the carbs again and do another round of cleaning to be sure.

 

ahh I didn’t know the light was normal. I did check the glass window and topped it off right above the glass line prior to adding oil

 

If your using starter fluid and doesn't run or have and combustion with that, then verify spark plugs and the spark on the all plugs. You should have a strong blue spark, if not check the cables, CDI, and Coils.

 

there is blue spark but I haven’t checked the cables, cdi and coils. I will do that next

 

I finally got the bike to start! Now I need to sync the carbs, because choke is off and the RPMs shoot up to 5000 upon starting. How should I go about this?

 

Are you sure you didn't reverse the throttle cable and the choke cable? Choke is silver, throttle is gold, unless they have been changed.

 

Highly likely, you would think on this age of bike?

 

Did you turn the idle adjustment down?

 

No, I didn’t reverse them. I double checked. Intake boots have cracks tho so I just ordered a replacement. We’ll see what happens after that. And yes, idle adjustment is turned down