Hey all... anybody ever taken their fuel pump out of their '93-95 CBR900RR and just let it gravity feed? Mine went kaput so I took the whole thing out and just hooked the tank to the carbs with a Goldwing inline fuel filter and although it's a temporary fix I used to roll home on, I'm just wondering what type of problems I may experience from this if I let it run this way for awhile until I can scrape the $170.00 bucks together to get a new pump. I know that the fuel pump is incorporated in the design of the bike and obviously serves a purpose, BUT... hasanybody on hereever done this and what were your results? I figure as long as I keep enough gas in the tank to provide enough pressure that I shouldn't have a problem overflowing the carbs because the needles will seat up and keep things from flooding, but not to sure so that's why I'm here.

Thanks to all in advance!

Chris : P

 

when i bought my 94 it was the same way, no pump just gravity. i ran it for 6 months not even knwing it should have a pump fitted lol. wasnt until i was rebuilding it i found it should have 1 there. managed to get 1 off eBay in good order for just under $50. as far as riding and running goes, i had no probs at all, even going onto the reserve a few times as well. it would run fine.

 

i've run mine with gravity feed since I bought it, the fuel cut relay died so I unhooked the fuel pump. runs fine, but eventually i'll hook it back up

 

Thanks for your replies guys... simple physics dictates that weight = pressure = gas to the carbs, but I just wanted to make sure from others experiences that this wouldn't interfere with anything within the fuel system... Another thing is my '95 900 doesn't have ram air, so it doesn't even need a fuel pump to offset the forced induction air pressure, and I can't figure out why they even put one on there in the first place other than to overcomplicate things, which is unlike Honda, and get more money from us at the stealerships... but oh well, at least it runs, and it runs way better without it. Again guys, thanks!

Chris : )

 

I was wondering the same thing when I had to replace my fuel pump a while back. Should have just lef the gravity setup. If you are going to buy a pump check out ronayers.com. I got mine for 120 from them.

 

i find him good to price things up then go to Evil bay to get it lol. or i just import it from UK as ron ayers wont and will not send to mail bos or PO boxes. find that very strange nowadays but his choice lol.. i think i paid just over $30 for mine. came with 6 months warranty as well


DONT FORGET ROTM HINT HINT LOL

 

This topic had been discussed many times before. There are guys here whom completely removed thier fuel pump and thier bike runs perfectly too. I think Jon is one of them? No news from him; long time....

Maybe its good to keep your fuel in always suffiecent level, if you don't use the fuel pump. My 97 converted to 99 engine has originally no fuel pump; no problem.

 

Okay so I have a 1994 Honda CBR900RR and I had to order a new tank. It seems like it may be gravity feed setup because the fuel line has a filter in the middle of it but there’s no fuel pump. How would I go about finishing the set up of the gravity feed setup?

 

The petcocks on the CBR900’s with fuel pumps (like my ’95 893cc) are not operated by carb vacuum, fuel pressure to the carburettors is interrupted, when the motor is not running, by the fuel pump not running.

However with gravity fed systems fuel flow is switched on and off by carburettor vacuum operating a diaphragm on the petcock.

Does your replacement tank have such a petcock? If not a petcock from a gravity fed CBR will do.

On the ’96 CBR900 (gravity fed) a tube from the diaphragm on petcock to the vacuum take-off on the bottom of (I think) the 2nd carb from the right (standing by the seat and looking down at the carb bell mouths) operates the petcock.

Note: for carb synching use a T-piece in the vacuum line from this carb to connect to your sync setup so that the fuel will flow.

 

So I got the new petcock and I hook the fuel line up to it & now I’m wondering how to get the fuel into the engine because if the line is unplugged from the carbs nothing is coming out.. idk if that’s normal but I’d appreciate it if someone would tell me how to start the process