Kawisaki Ninja 250R discussion

[cat0020]

I am not really conscious of riding conservatively to maximize "fuel economy", but I do make an effort to use the brakes as little as possible even with my cars.
Speed trimming is most done by closing the throttle, but not downshifting. Look far ahead and prepare for the possibly need to come to a stop and use the brakes as lightly or late as possible.
Always look for ways around slowing/turning or stopping traffic instead of grabbing the brakes.

[Jay2TheRescue]

I don't know what the results are yet, because I haven't used a full tank of fuel in my bike yet, but I have been doing somewhat similar things. Coasting up to lights, and I run my bike up to 6th gear as soon as I get up to the speed limit.

[Project84]

I just got done doing a bunch of routine maintenance that I had no prior experience in doing.

For those interested in knowing, the chain adjustment, valve adjustment and carb sync are all what I'd call intermediate skill level jobs. This write-up will serve as a referrence to those who find this thread in the future.

Having no history of working on a motorcycle I was able to adjust the valves from a printed how-to found on the web. The procedure wasn't bad, just tedious. Overwhelming to see the bike all torn apart too.

After disassembly, valve adjustment, new spark plugs, reassembly and ride to warm the bike up (and to see if I in fact did it w/o screwing up, LOL) I had to disassemble again to get to the carbs for the syncing. Not too bad of a process either so long as you don't fool w/ the adjustment screw much. I got an itch and decided to twist the adjustment screw a few different directions rather quickly so as to really mess it up just to get practice with learning to dial them in evenly. That was a learning experience I'm glad I did but wow, very frustrating. I did the sync by using a homeade slack-tube manometer from plastic tubing and some ATF fluid, I zip-tied the tube to a paint stick to get a visual referrence of how the fluid was flowing/which carb was pulling more vacuum.

I then cleaned the air filter and lubricated it w/ fresh oil.

It might just be my imagination but after all this work, the bike really does feel much smoother through the RPM's and a little more powerful. I think I'd contribute that mostly to the valve adjustment. The intake's weren't bad but the exhaust's were pretty out of spec. The carb sync also dialed in some power, I noticed while messing w/ the adjustment screw that the idle I'm used to hearing was actaully a little "lopey" from the carbs being uneven... upon getting the manometer dialed in, the idle sounds more smooth and precise and the bike rides better.

While I was in there I adjusted the throttle linkage to tighten it up, no more sticky throttle on take-off.

I need to JB-Weld the gas tank again where the fuel leak is because the other stuff I put on there shrank and split. Once that's done (along with an oil change sometime this week) I'll be filling up again and adding a few oz. of seafoam, and hoping to reach 70mpg. Cat0020 is killing me with his mileage.

Depending on how I feel next spring when I upgrade bikes, I may keep this one. If I do, I'm buying new sprockets; 15 front and 39 rear as well as a new chain. That should put my MPG way up.

Right now the front fairing is still off and I kinda like the street-fighter look. haha

[cat0020]

Good work, how many miles on your ninja 250? how far off were the valves? tight or lose? on the exhaust or intake valves?

[Project84]

7,2xx miles on the Ninja, so it was 1,200 miles past the 6k miles service interval. I bought it at 5,200 not knowing it's maintenance history.

Intake's were a bit tight, not too bad; probably within spec at the tighter end. Exhaust's were really tight and beyond spec. I set both of them to the losser end of the spec. .13mm intakes and .15mm exhaust. You can go .16mm exhaust but my feeler went from .15 and the next was .18mm.

I've only put about 20 miles on it after the service but it felt much smoother and pulled linear whereas before it would peak out around 9k and fall on its face. Now it seems there's power all the way to 13k but still some trail-off at the higher end.

[cat0020]

Lil' Ninjas usually get tight clearance on valves, but once set proper after initial adjustment/break-in period, the valves stay put pretty well.
My valves were still spot on at around 5k mi., with the way I ride probably stay that way for a while.

[Project84]

Perhaps I should stop beating the pants off mine. Afterall, the results still aren't very satisfying. I must admit though, I'm content at 60mpg considering I redline gears at least 70% of the time I'm riding and when on the interstate the speed limit around here is 70mph so I'm usually rolling 80ish which puts the bike up near 10k rpm.

60mpg return on riding like that is impressive to me anyway.

[cat0020]

On my 3-times a week, 94 mile commute, I rarely get above 60 mph, zero highway miles, lots of twisties and backroads, 80% of my travel speed is between 45-50 mph while engine revs ar arond 5-6000 rpm.
I weigh about 160 lb. with full riding gear on me, carry about 12 lb. of books and computer w/me during the commute in my "hard" luggage:



Another 6 to 8 lb. in the tank bag.

[Project84]

Why'd you remove your lower fairing? Mind selling it?

How do you like the laminar lip?

One more question - why do you always prop the bike up on things under the stand? Do you travel w/ that on you at all times or just leave it in the driveway?

[cat0020]

Originally Posted by Project84

Why'd you remove your lower fairing? Mind selling it?

I leave it off since I ride it so much, in a couple more weeks, I'm going to change the oil/filter again. I'm keeping the lower fairing, put it back on bike when I sell the whole moto.

How do you like the laminar lip?

It's pretty nice, deflects bugs off my helmet/face, allow decently clear airflow around my head, but at higher speed it kinda bends the windshield back & downard, I need to fab up some support plates behind the windshield.

One more question - why do you always prop the bike up on things under the stand? Do you travel w/ that on you at all times or just leave it in the driveway?

Yes, I prop up the sidestand whenever I can, less pressure/weight on the sidestand so it's less likely to put holes on the hot pavement of my driveway. I also do it when I park at other people's driveways, most people appreciate the effort not to put holes on their driveways.