Still having a fuel economy problem.

So, I fixed my fuel leak... or so it seems... but the swivel on the carbs fuel intake nipple is moist with fuel still, while the engine is running. I'm trying to find out what O rings to get because I don't even SEE orings on the swivel. I'm thinking WiredGeorge maybe didn't put them in? Seems kind of odd because he did such an amazing job on them. It's been about a year since I got them back, so it's well past the warranty period and I'm not sure I'd want to be riding my Rebel around till I got the carbs back.

Anyway, I'm only getting around 36-38mpg. What else could be lowering it? Any fuel coming out of the input nipple swivel is probably negligible, since it's only a little moist while the engine's running.

I'm kind of new at this mechanic thing, but I'm learning fast, mostly due to your help and the help from people in a few of local MCs I've befriended.

Are you sure fuel is not getting past the hose and fuel tee of the carbs? Did you install a hose clamp?
I have a 750-H2 LTD with 4 into 1 exhaust, k&n inside airbox, dyna coils, stock kawi TCI ignition and Dynojet stage 1 jet kit. I get 100km with 6 liters, that would be 39 MPG. That is riding at 110 km/h.

I'm pretty sure it's not getting past the tee. I installed a wormdrive clamp so I can be absolutely certain. I could maybe tighten it down a bit more, but it looks like the right amount of compression on the hose diameter to me.

Considering who I bought the bike from, it's possible they had an upgraded camshaft installed (and I wouldn't know if it was or not since I'm not an expert yet). Could that possibly be responsible? The person I bought it from is a drag racer and they got it from another drag racer.

As for me, I bought it mainly because I wanted to learn to maintain bikes through trial and error, and I also wanted a bike to ride, and this is what I found. I have however since come to absolutely love my LTD. It looks like sportster, sounds like a sportbike, it sits in the happy medium where I don't get any lip from the stuck up variety of cruiser or sportbike riders.

Setton wrote: So, I fixed my fuel leak... or so it seems... but the swivel on the carbs fuel intake nipple is moist with fuel still, while the engine is running. I'm trying to find out what O rings to get because I don't even SEE orings on the swivel. I'm thinking WiredGeorge maybe didn't put them in? Seems kind of odd because he did such an amazing job on them. It's been about a year since I got them back, so it's well past the warranty period and I'm not sure I'd want to be riding my Rebel around till I got the carbs back.

Anyway, I'm only getting around 36-38mpg. What else could be lowering it? Any fuel coming out of the input nipple swivel is probably negligible, since it's only a little moist while the engine's running.

I'm kind of new at this mechanic thing, but I'm learning fast, mostly due to your help and the help from people in a few of local MCs I've befriended.

36 - 38 mpg is actually pretty good fuel economy. I very rarely get any better than that with my KZ650. Keep in mind that the fuel in the US is laced with 10% ethanol, and ethanol provides only 2/3 the energy per gallon as does gasoline, so your fuel economy will be less than those whose fuel doesn't contain ethanol. I've owned my 1977 KZ650 since it was new and I saw a drop in fuel economy when ethanol was added to the available fuel. Ed

zfacts.com/p/436.html

I would think a 750-4 would get 40-45 mpg or thereabouts. some guys have claimed a bit higher than that.
My 81 650-CSR gets 45-52 mpg & our fuel has ethanol. every now n then it'll get 55 on the highway & as low as 42 around town when over-revving. the csr has a 13T Fr & 33T Rr sprocket. I think the 750H Ltd is 13T & 32T.

Is the bike stock? If there were any changes to the air box, exhaust, carb jetting, gearing, etc, then that could explain the poor mpg (which as Ed says, isn't really all that bad).

Other things could be related to the general state of tune. Is the air cleaner fresh? How long since the last valve adjustment? How old are the spark plugs and have you ever check the coils and spark plug leads to be sure you are getting a good spark?

martin_csr wrote: ....
My 81 650-CSR gets 45-52 mpg & our fuel has ethanol. every now n then it'll get 55 on the highway & as low as 42 around town when over-revving. ......

I'm envious. My bike runs great but has never done that well; even when new with non-ethanol fuel. Maybe the changes Kawasaki made to carbs after 1977 helped. Ed

Other differences: the csr airbox holes are larger (56.5mm. the earlier 650 airbox holes are 47mm outer & 40mm inner) & the sprockets give better fuel economy (13/33 compared to 16/42). also, the csr has electronic ignition, but I don't know if that has any bearing on the mpgs. Hy-Vo cam chain.

I've always got right at 40 or a hair under too...... and I'm think in after sitting a year there is a good chance those tee o rings (if that's what it is) will swell up and stop being damp in that area.

I'd check the valve adjustments.
Steve

I get 40+ mpg @ 80 mph on my highly modded KZ650. I rarely see below 40 mpg in the 40 years I've owned it. If the leak persists an old school trick is to separate the carbs and wrap plain old Teflon tape around the o rings and reassemble. This has worked for me every time and it's a long lasting solution.

swest wrote: I'd check the valve adjustments.
Steve

Steve, that is the same thing you reply to every post on here! Not that you're wrong