Do people still hop on this forum occasionally? I am in the process of buying my first motorcycle from a friend, he had the bike sitting for years, told me it runs all I need to do is change the gas and cleaned the carbs.

I pulled the carbs and cleaned them got all new jets, pilot screws(pilot screw #3 was completely missing), gaskets and fuel filter and fuel pump, and plugs and float needles

still won’t start just turns over and backfires I cannot get it to even idle so I can’t carb tune(battery is good, I need to check the plugs again)

I read manual setting for the pilot screws is 1 and 1/2 turns out(set all the screw to that)

I took the air box off and there is fuel spitting out of the top of carb 1 and 2 but very dry in carb 3 and 4
what does this mean?

after researching peoples past experiences on this thread my next step is going to be checking the bowls to see if all carbs are getting fuel


any advice or input will be very appreciated

thanks

 

People are on the forum all the time.
To answer your carb question, good money says your carbs are not clean enough. They require to meticulous attention and patience. They must be fully disassembled. Meaning they have to be separated from each other and every screw, jet O-ring, etc. must be gone thoroughly. Modes of cleaning varies from person to person but it will involve either a chemical cleaning or ultrasonic cleaning or a combination of both, with multiple iterations of each.
Not knocking your friend, but if a bike as been sitting for years, there's no telling what it actually needs. Cleaning the carbs is a guarantee though.

 

Means float-valves aren't sealing in #1 & 2 and letting bowls fill up and drip liquid petrol into engine. Be careful as this will hydrolock engine and #3 & 4 cylinders can fire and generate enough power to bend con-rods in #1 &2 and blow holes into pistons.

Yup, especially if bike's been sitting for years, carbs need full restoration, not just spritz of useless spray carb "cleaners". Which no longer work due to removal of chlorinated compounds. Here's general outline for proper carb cleaning:

“Cleaning” can mean different things to different people. Last house-cleaning outfit I used didn’t think that “cleaning kitchen” meant restoring top of fridge to showroom condition or pulling out all appliances and cabinets to scrub floors underneath. You’ll want to disassemble carbs down to every last nut, bolt and individual component.



Here’s link to passages that needs to be scrubbed from end-to-end. Different bike, but CV carbs tend to be very similar.
N4MWD's blog: Secret Ninja 250 Carburetor Passages

1. Scrub out all hidden secret fuel-circuits beyond jets with brushes. . I like to use 75/25% acetone mix with PEA-based fuel-system cleaner such as Chevron Techron, Red Line SI-1, etc.

2. Soak in ultrasonic cleaner for hours using polar solvent (PineSol, Totally Awesome, vinegar, etc.) Be aware that Simple Green dissolves aluminium, so avoid it.
3. Scrub again with brushes. Pay particular attention to holes where fuel-circuits exit into carb-venturi (neon green dots in photos). Poke those out with soft copper wire. Remove deposits but be careful not to remove any metal as size of these holes are critical to fuel-metering

4. Be sure to completely disassemble emulsion tube and poke out all lateral bleed holes with copper wire. Same with all jets and bleed holes in carb venturi. Soaking and scrubbing won’t clean these holes and you’ll find wire pushes out dried plastic petrol plugs similar to grains of sand.


5. micro soda-blast all circuits and bleed holes to clean out debris loosened and left by scrubbing. Use finest soda available AircraftSpruce - mini soda blaster

6. replace all rubber parts: float-valves, O-rings, seals and even slide diaphragms as needed.

7. adjust float-levels with final wet-test


8. sync carbs with manometers. While old-style analogue gauges work, I prefer modern digital versions. carb-sync gauges

Basically, idea is to restore carbs to brand-new factory-clean OEM condition. Many expert mechanics have had to pull carbs 4-5x for ever deeper cleaning before bike would run properly. One guy had to pull carbs 10-TIMES before bike would run right. Once you’ve done this complete list above, carbs will be factory-fresh clean and bike will run like brand-new. Aside from costs of equipment, you'll also need decades of experience cleaning hundreds of different carb models to know where to stick those scrub-brushes and where to poke wires through.

I suggest sending them to this outfit. Expert workmanship, reasonable fees ($200-250), quick turn-around. Bike will run like brand-new off showroom floor.
https://customcarbservices.com

I send my carbs from my race-bike every other year. I run in stock class and factory-fresh clean carbs is one mod that makes huge different over others with clogged dirty carbs.

 

H about using Purple Power cleaner? Almost used Simple Green to find a leak on the stator cover side. Not good for aluminum correct?

This is amazing I need to go ahead and take care of these carburetors and clean them completely. All bolts, o rings. Jets, gaskets replaced and cleaned with simple green which is not right, correct?

Has anyone tried this manometer?

 

Ive used Simple Hreen before with good luck while using my ultrasonic cleaner. I did experience any negative effects. .
some people jhVe used PineSol. I personally don’t care for the smell of it so I don’t use it. But I can imagine it would be good.
others have boiled the carbs in lemon juice.
I also like using chem-dip.

 

This replay is assuming youve never had or seen the bike running.

I appreciate that the majority of answers here are related to carb cleaning but i'm not sure this is your problem so I wanted to suggest something different and something you can very easily do to more accurately determine the root cause of your problem. Its related to the fuel pump. (yes i know youve bought a new one but test it anyway yo uneed to know it works! If youve bought a cheap chinese one its not unheard of for them to not work out of the box.

My F3 stopped working recently ... symptoms just like yours .... crank it over for ages, very occasionally might sound like its fired once on one cylinder but basically no ignition taking place at all! .... until eventually you get an epic backfire. Sounds a bit like your symptoms .. no?

So ... mine was a bad fuel pump or more precisely bad contacts in the fuel pump which, thankfully, can be changed very cheaply and easily - £18 and no more than 45 mins work. (New pumps here in UK retail at £318 at wemoto!!)

Its very very easy to test to see if this is your problem so before you go to the effort (and its a considerable effort) of removing the carbs and stripping them, try this ....

Take the fuel / filter hose off the pump ... and attach it directly to the petcock valve on the bottom of the tank. This is known as 'gravity feeding the carburettors', basically running fuel directly from the tank through the filter and into the carburettor. Now try starting it (use choke obviously .. it's cold). If it fires and runs (might take a few seconds to get the float chambers full) then you know that the carbs are ok and you know that the ignition circuit is ok. No pissing about stripping carbs, no pissing about removing and checking coils!

Now, if it does run like this then you know the problem is one of two things

1) Fuel Pump
2) Fuel Cut off relay

FYI, my bike was dead and yet as soon as I gravity fed it she fired straight up like nothing ever happenned!

The pump is easy to test. Run two wires from negative and positive on the battery to the fuel pumps electrical connection. (On mine its black blue wire for the pumps negative and a green wire for the positive. The pump should run non stop when you attached the wires (dont leave it running, it relies on fuel to keep it cool). If it doesnt run or runs for a split second only then the pump is bad and it's probably the contacts. If the pump does run non stop when tested in this way then you need to check the fuel cut off relay (right hand side of bike under rear plastics) part no. cf318. A common failure on this bike.

I have read of people finding a broken wire between the relay and the rest of the loom but generally it seems its the relays themselves that fail. Having said that ... i had a failed relay on my bike when i bought it (was a very unloved project bike) and it didnt stop the engine running, just stopped it revving.

Testing both relay and pump takes just a couple of minutes once off the bike so within the space of 20 mins or less you should be able to eliminate these from your diagnosis or prove that they are the fault. 20 mins vs a weekend of bike stripping, carb removal (a bitch with old hard carb insulator rubbers) is a no brainer. I strongly advise you to do this before you try anything mentioned above.

This may not be the cause of your issue but its the easiest and simplest thing to do and enables you to diagnose the problem with more accuracy.

If the bike still doesnt fire when gravity fed then the next easiest thing to check is for spark. Take a plug out, hold it against the frame (with HT lead attached) and turn the engine over on the button. You should see a spark arcing between the plug and the frame. If not, its an ignition problem and you dont have to pull your hair out getting the carbs off!)

Obviously a bike being sat up long term isnt great for it but even so and even if the fuel was bad, the chances of you getting no ignition at all are still very very small. Yes it can happen but its more likely something else. If it was running when it was parked up (and stored inside) then there is no reason to think that the coils have both somehow failed or that every single slow running jet is blocked .. its very unlikely unless the fuel is literally 15 years old and turned to jelly! Don't get me wrong, you want a clean carb on this bike, it can be temperamental like that but there's much more simple and likely things to check as I mention above.

I'm not a mechanic but I'm pretty handy and I have just done a nut and bolt restoration on my F3 (well 6 months ago) so I know both the carburettor and the ignition system quite well. Didn't know anything about the fuel pump until a week ago when it failed, now I like to think I know it very well!

I've got 3 vids on youtube showing my 'restoration'. Money is tight so I couldn't make it like brand new but I did strip the carbs / forks / brakes / powder coated the frame / swingarm etc. Maybe there is something on there that might help. This is part 1 - https://youtu.be/S1truuut8Q0
Best of luck, please do keep us updated on what you find!

Regards

John