Help Adjusting mixture and multiple bike starts.

You're draining a car battery in 5 start attempts? Is your starter melted? If your jump leads are not good enough, you may be only drawing a few amps out of the car battery and relying on the bike battery for most of the current. Less than 12.4V is a flat battery, make sure your battery is charged up properly and that you car battery is working properly.

 

Stop cranking it so much! If it doesn't start in 5-10 seconds, something is WRONG with bike. Continually cranking it will not remove corrosion from wire, will not fix worn-out crank-sensors, will not replace plugs or plug-wires for you, will not clean dried petrol plugs from carbs, will not scrub carb-passages clean, not not ultrasonically soak your carbs, will not replace worn rubber carb manifolds or plug rips and holes in them, etc.

So, after 2-3 attempts, max, STOP the INSANITY!!! Doing same things over and over again expecting different results. Instead, pull out multimeter and test all electronics, all switches, measure resistance of each and every single wire end-to-end. Pull out vacuum-gauges and measure manifold pressure. Something is WRONG with bike, fix that problem and symptoms of difficult starting and dead batteries will go away!

To prevent destroying batteries, keep it on smart-charger full-time 24/7. When cranking, use jump from extra battery or car battery (car off). Charged car battery should let you crank bike for 5-minutes straight. You'll fry and burn out starter in that time and bike still won't start because problem is not battery or starter. Find actual problem and fix it. Then bike wil start easily.

 

BTW - "cleaning" carbs is more than just spraying "carb-cleaner" through jets. Really needs complete disassembly down to every single component and scrubbing everything until it's factory-fresh clean. Use nylon brushes to scrub out all hidden fuel-circuits between jets and carb-venturi. Use PEA-based fuel-system cleaner mixed with acetone to brush out passages. Replace all rubber O-rings and seals (pilot adjustment O-rings), fuel-rail O-rings, float-valves, float-bowl seals. Soak in ultrasonic cleaner for 4-6 hours. Scrub with brushes again. Poke soft copper-wire of matching diameter through all bleed-holes. Finally, micro soda-blast to clear out all circuits of flake crud you've dislodged with scrubbing.

Bike ran perfectly fine off showroom floor with carbs in factory-fresh clean condition. Fact that it doesn't run that way now, means carbs aren't factory-fresh clean. Many, many people have had to pull their carbs 4-5x for ever deeper cleaning and bike finally ran like new. I suggest not doing that and going with full restoration on next attempt.

 

Yeah, and do compression-test and post numbers you got here.

 

At stock 1.5-turns out on pilots, it should run like brand-new. Hanging idle is sure sign of lean-mixtures. Cause is dirty carbs. Previous owners tried to make up for dirty carbs by unscrewing pilots more to compensate. But it only works somewhat. Similar to desperate measure of installing larger-jets by many people to make up for clogged carb passages. But it's not really fixing really problem.

Be sure to get variety of nylon scrub brushes and solvents to scrub out fuel-circuits beyond jets. Each and every one of jets has passage behind it that leads to carb-venturi. You'll want to scrub path of petrol entire way. I posted some pictures of types of fuel-circuits involved that needs to be scrubbed here: https://2fiftycc.com/index.php?posts/135362/

 

Don't clean spark plugs, just replace them. Too easy to have a short up the core when under compression - you'll get a spark when the plugs are out, but not when in the bike.

 

We've just had someone else with incredibly low compression numbers, although consistent - turns out the issue wasn't compression at all, BUT the location of the schrader valve at the gauge meant that the volume of the hose lowered the numbers in the results
His bike wasn't firing on 1 cylinder for another reason besides compression.

Read here
https://www.2fiftycc.com/index.php?threads/fzr250-project.10828/page-9

Don't know if your compression tester is the same, but you've got consistent numbers with low readings on all 4

If you do the numbers, you've got ~5 atmospheres pressure
5:1 compression
Swept cylinder volume is 62.5cc, compression ratio 12.5:1
Cylinder head volume is 5cc
If that tube has a volume of ~7.5cc before the schrader valve you'll get damn close to the compression numbers you have and there aren't any problems with the rings

 

no, the bleed-valve is that right-angle thing sticking out just below gauge. What this does is include volume of hose into combustion chamber and gives artificially low numbers.

I used similar gauge to test my turbo Porsche 951 with 8:1 compression and it reads 150 psi.
Use exact same tester on my Ninja 250R with 12.4:1 compression gives me 140psi, WTF?@!!! Manual says 195psi!!!

Well, since volume of hose is fixed, it contributes to larger errors on smaller combustion chambers. Small 250cc 2-cyl engines have smaller combustion chambers, it throws those reading off more. And even smaller 250 4-cyl would have smallest chamber and largest error.

yeah, repeat with carbs off and let's new numbers. Engine's most likely fine since it's even across board.