I don't know about hooking the fuel pump straight to the acc side of the switch. There is a lot going on when you need to start the bike. This being part of the reason your headlight is wired into your start switch, just so it shuts off while your starting the bike. That's just me though.

$20 for a battery tender Jr. I swear to you it will save your life and you won't even know it's doing it.

 

Ya, if you wire it to acc then the bowls are full before you ever hit the starter. The way its wired stock the pump only primes when the motor is cranking. The pump has a pleasure switch in it, it shuts off as soon as the bowls are full.

Under normal use its never an issue. But if you run a small battery like me then you risk killing the battery trying to fill the bowls if you run the bike out of gass or afer you have drained them to clean.

Basically my suggestion shuts off the pump for cranking not starts it for cranking like stock. I think we are thinking along the same line Lep....

 

Well for noow the pump is working and i will leave it until i get the bike to run properly. I have cleaned many carbs and thought i got these pretty well. I am going to change the plugs and see what happens. If nothing I will clean the carbs again.

 

Well I checked the plugs, all look great besides excessive fuel on one, and some oil o the other. I cleaned them and they look brand new. The previous owner said they were replaced shortly before it was parked.

I cleand the jets again and It ran a lil then died. I tried again, this time with the throttle cracked just a hair and it ran for about 30sec at 3000rpm then died and it would just back fire after that. You guys think the carbs need to be sync'd? Any other suggestions would be great.

 

I also noticed the ports on the "intake plenum" where the carb boots are had been capped with rubber caps that were all dry rotted. I capped them with better rubber caps. This may have been a vacuum leak. idk.

 

It's pretty simple to sync the carbs if you already have access to them. Unless they are WAY off, I doubt that is the issue. I was still running a 12 second 1/4 mile with one of my carbs not even opening.

Do you have a compression gauge? have you replaced the gas? what kind of gas is in it? premium? regular? Have you checked the spark yet? is there a banana in your exhaust pipe? lol...

The compression on each cylinder should be within 10%, My f3 only really runs well on 92, but i put 92 in my dirt bike and couldn't get it to run. Find a spark checker and check to see if the plugs are getting any juice. There is a difference between spark colors if you use a spark checker that shows the spark itself. white is bad ***, blue is normal and yellow is ****. how is it backfiring? every few seconds or once a minute? how bad of a backfire?

 

The bike is pretty much stripped, so its easy to get to. I do have a compression tester. I will try to check the spark this weekend. It after it ran for 30sec it backfired almost ever time i cranked on it. Some being small and some being really loud.I have 87 in it right now bc thats all i had at the house. I will get some 93 and try that as well.

 

Backfired revving up or down? Check for air leak.

 

it only back fires while cranking. I got it to run for about 10 sec again. But then would back fire and shoot a blue flame out the pipe. Im assuming theres a vacuum leak somewhere but i cant find it. The plugs looked fine but could they still be fouled?

 

ok, this is just a few shots in the dark.... It only backfires when trying to crank over, this is caused by a few things going wrong. The flame out the pipe leads me to believe that there is unburnt fuel in the exhaust when it's turning over, finally it fires and BOOM all the unburnt vapor in the pipe goes pop!

You need a spark checker, yes honda's have a very complicated vacuum system, but it rarely fails just from a bike sitting too long. Check the spark, I bet something is still wrong with your delivery system. This means coils could still have grounding issues, wires are broke, wires aren't even connected, coil failure, bad stator.

Check the spark. That will tell you much more.