I hope this isn't super obvious but it probably is. I did some searches but I can't find an answer. I just brought home a '90 CBR1000f yesterday, it was running fine. I unloaded it from the bed of my truck today and went to fire it up and I'm not getting fuel! Plugs are dry anyway. I pulled the main fuel line off my petcock and turned it to the on and reserve position and I'm not getting any flow out of the full tank. I popped the cap to make sure there is not vacuum, still nothing. Just seems rather odd, my other bikes just flow if you turn the petcock on (pretty simple eh?) but I've never had one of these and I think I'm just missing how this one works.

 

Indeed you are missing how it works, Mk2 onwards have a vacuum line to the number 4 (carb) which opens a rubber diaphragm to allow fuel flow when there is vacuum in the carb.

I have a MkI so can't walk you through the intricacies of it I'm sure someone will be along soon.

All the best

 

If you track this one back to the carbs, pull it off (at the carb end) and then suck on it you should get fuel flow through the petcock. You won't get a mouth full of fuel. If your carb bowls are somehow empty of fuel (?) you can do this for about 15 seconds and they should fill up again.

 

Did you go and take that photo specially to reply to this Kevin?

That is very generous and helpful of you. Well done that fellow Kiwi.

 

It was actually in my stock of photos from when I pulled the plumbing off to change the CCT. I'd only had the bike a little while then, so I took a bunch of photos so I knew where everything went back.

Hopefully it helps thedrewski out!

Merry Xmas,

 

Thanks guys! I'll give it the old suck'n'blow when I get back from work
...so if that works it seems I'm still not getting fuel. I'll just follow the lines and try to find where the flow stops. Sounds like a jostled vacuum line is a possibility, maybe it popped off during loading or unloading. It ran fine Saturday at the PO's house!
Without digging into this yet I don't know if this is related but this thing has a slow crank. PO said it always has but starts anyway. The starter just seems to turn real slow. He said he replaced the starter, R/R and stator and it still does the same. R/R certainly looks brand new, new battery holds 12.5v. I'll tuck in after work today and get myself familiar w/ the bike but I wonder if these two problems sound like a couple related issues to anyone here?

 

Could be. If its cranking real slow you wouldn't create the vacuum needed to open the petcock.

Slow cranking may be starter clutch.

On my '94, the petcock vacuum line hooks to the #1 cylinder vacuum port on the head. Its the line bohdan pointed out. Nice photo!

1-Pull the saddle
2-Pull the side covers
3-remove the two 8mm bolts in front of tank near the gauges
4-lift the front of the tank, there is a tank prop that holds the tank up
and should drop in by itself
5-left side of engine near frame is the vacuum port
6-If you have a hand held vacuum brake bleeder, apply vacuum to line and
fuel should flow. I don't think you can suck that hard.

 

Man you guys are quick with the help! I really appreciate it. I definitely have work to do when I get home today.

 

Even quicker with the wisecrack

Let us know how you go.

Cheers, SB

 

Once again thanks for all the advice. I usually come in asking a billion questions like an idiot!

Whatever is wrong is definitely something big. I came home today and gave her a crank. Full choke, kickstand up, in neutral, kill switch to on, little throttle twist no fire. I immediately pulled the plugs and they are still dry and don't smell like fuel.
I opened the petcock and applied some vacuum to the hose off the carbs, fuel came easily out of the tank. Seems the fuel valve works.
I pulled a float bowl screw and fuel came out, fuel is at least getting to the carbs - doesn't seem to make it to the plugs though.
Here is a kicker: I got ahead of myself yesterday and didn't check for spark. I checked all four and nothing. Now I'm really dead. So I take the kill switch apart and check for continuity - all good! Switch seems great.
I checked all my fuses with my multimeter (except the 30 amp on my starter solenoid, that obviously works). They all check fine.
I hit my frame ground with a little 400 paper and dielectric grease.
I can't remember what else I checked if anything. I ran out of light in the bike shed (no electricity!). I plan to check power to my coils and kickstand switch tomorrow. For now my battery is sitting on the charger, I ran it down to 12v even.
I really think I'm tracking down a short seeing as it came home in light rain in the bed of my truck. It didn't get that wet though, so I'm just looking for anything really.