Hi, I am the new owner of a 1995 Ninja that was given to me by my wife's friend (3rd vehicle given to me in the last 4 years: others were a 1986 Porsche 944 and and 2004 Land Rover Discovery 2. I must look like the patron saint of lost vehicle causes).

The ninja has 4,600 miles on it and has been sitting in a barn here in Texas since 2004 (guessing as that's the last time it was registered).

Working from the top down, I have taken off the tank: it was badly rusted inside and the gas had turned into a nasty gel so I flushed it first with water to get the big stuff out, then cleaned it with muratic acid (have done this before with great success on cars), put in a little WD40 to coat the inside of the tank to prevent it from surface rusting (drained the excess) and replaced the petcock with a new one. I also flushed the fuel and overflow lines with some acetone (carb cleaner).

I am now onto the carbs: know how to remove them and have rebuild kits. I will also lube the choke and throttle cables

Once carbs are rebuilt, I will replace the plugs, and while the plugs are out and there is no compression resistance, want to squirt some oil into the cylinders and turn over the engine to coat the dry walls a bit.

Any advice on how to do this? My brother tells me that if the wall/rings are a little rusty and have rusted together (possible as one valve or other was open and allowing moist air into each cylinder) and I use the starter to turn the crank, I may break a ring, so I should "wrench" turn it first like you would a car. Any idea how to do this and which direction to crank it as there is no obvious exposed crankshaft end-bolt like there is on a car engine. And how much oil would be appropriate to squirt in as I don't want to foul the plugs right away?

Regarding plugs, I plan on using CR8HSA plugs rather than the spec'ed C8HSA as they say the "R" versions are backward compatible to 1995 and older 250rs (already bought the R plugs -- is this going to be OK?).

Once this is done, I plan to drain the oil and replace the filter and then crank her up and see what happens -- I'll invest in flushing and if necessary rebuilding the brake masters/calipers after I have a running engine.

Does this sound like about the right procedure or is there anything else I should do before the "moment of truth"?

 

Lots of looks but no replies: is it something I said?

BTW, looked at the title and it is actually a 1992, not a 1995. 26 years old, so I get to register it as an antique/classic in Texas: $50 for 5 years AND no inspection required.

Back to the project at hand. In getting the carbs out, I am thinking that I want to get rid of that airbox and instead go with individual cone air filters for each carb.

I will have to build a battery holder, but that shouldn't be too big a deal.

However, what do I do with the crankcase ventilation tube that currently directs the crankcase vapors back into the carbs thru the airbox? Just vent it to the air or rig up some plumbing to each individual air filter/carb?

Thoughts from anyone who has done this (especially the successful ones ) would be appreciated.

 

Hi Austin,
Welcome. And congrats on the Ninja. I've heard before that free bikes are often the most expensive, so have fun!
Nothing you said. Probably a lot of the view are bots that patrol forums.
I'll offer what I can here...
There are coatings for the tank. If you get it all running, probably look into them to prevent future rust.

I'm not sure on what kind of oil to put down the cylinders. Would one want to use a penetrating oil? Not sure, but I think I'd give it a try if you think there may be stuck rings. Spray some in and let set for a while if rings seem sticky. I've heard some of the best penetrating oil for rusty bolts is 50/50 ATF & Acetone. Could that be used? I'm not sure. I'd look around to see if I could borrow a bore scope to peek in and see how bad they are.

On the left side of the bike there is a plug, maybe about an inch in diameter, in the center of the case. It usually needs a large flat head screwdriver or a large washer in vice grips to fit the slot. Pull that and you'll find the crank nut that can be turned with a wrench just like a car. My experience with kawis is to turn it counter clockwise. It may not turn clockwise, or not far, before seeming to bind up. Not sure why it binds. There will also be another plug above this one where you can see the flywheel and timing marks. Just fyi.

How much oil? Not sure. Maybe a teaspoon? I wouldn't worry about fouling plugs, I'd be more worried about the motor. Plugs are cheap, comparatively. I think the "R" just means resistor plug, when is less likely to interfere with radio, etc. Should be no biggy.

Airboxes are often design for performance and individual cones may not perform as well. But they may look cool. Just FYI. I'm a fan of airboxes, but hey, it's your project!

Find a little air filter to go on the end of a rubber hose for the crankcase vent. I wouldn't worry about trying to send it back through the carbs, but protect the vent with a filter. I've done this before on a dirt bike.

Sounds like you have an interesting project. I'm curious to hear how it progresses. Just FYI, this place doesn't get a lot of ninja action. Most activity is for the KLX250 dual sport. If you search around the webs, you'll probably find some ninja sites with better activity and input for your project. See if you can find a service manual. It will help, A LOT.

Cheers!

 

Thanks for replying and letting me know I'm not alone.

I watched some utube videos on turning over motorcycle engines that have sat for a long time.

Suggested fluids are either WD-40 (supposedly burns well) or Marvel Mystery Oil. Both are considered "penetrating". They all say that lubricating engine oil lacks the necessary penetrating properties to break any rust binding rings to the cylinder wall.

Alternately, you can circulate a mix of Marvel and diesel thru the entire crankcase using an aquarium pump. Cool videos of this method on utube as well. There appears to be a breather hose on top of the head somewhere: you pump the mix into the oil filler using the fish pump and it comes out the top at the breather to be recirculated, but given what I know about engines not sure how any of this fluid ever gets into the compression chamber (unless you have a leaky valve seal), only the underside of the piston.

I am going the WD-40 route first and see what happens.

Appreciate explaining where the crank nut is. Really helps.

Again from utube videos, best approach seems to be 3 step: 1) put bike in top/6th gear then rock back and forth; 2) turn the engine manually at the crank bolt; and 3) after 1 and 2, "blip the starter.

Airbox is going. Joke seems to that they built the 250 Ninja frame around the airbox and not the other way around. From other threads, decided to try a K&N R-0990 "pod" for the carbs (a single filter with two flanges) and a K&N 1340 for the crank breather nipple.

No biggie though, need to remove the rear wheel anyhow to re-skin it with new rubber.

Only challenge then is building a battery holder as the stock one is molded into the airbox (right? the bike is at my brothers's house and it was a couple of days ago that I took it apart so can't remember whether the battery holder is stand-alone or integrated into the airbox).

Tearing down and rebuilding the carbs tonight. Again, other posts say that when converting to a "pod" filter setup, you need to re-jet to compensate for the additional airflow. It appears that stock is a #105 jet and to run well without the restrictions of the airbox, you need to change to a #110 jet.

Will keep you updated. So far, into it for about $150, will be $250 after new rear tire. Cheaper than buying a running version, which seems to start at about $800, but if I were actually buying a bike would probably have gone with a 600cc+ and a BMW or classic Triumph or Norton or even Enfield instead of a cafe racer (of course, then we're talking several thousands of dollars).

Still, sounds like this 250r is going to be cheap and fun once it's running.

 

Wow. Nice job on research and glad to hear you found some other resources. I think filling up the case with Marvel and diesel will get to all those other bearings that could be seized up. If you're just interested in piston and rings, than WD40 down the plug hole makes sense.

Some guys have been going with the much smaller lithium battery packages. I'm not a fan yet, but they are so small they can be fitted more easily.

Larger jets makes sense. You don't want to go too lean and burn it up.

Thanks for following up. I keep my eye out for Ninja 250 as a commuting bike. Fantastic mileage and inexpensive with, from what I've read, a more upright seating position which I like. Get that thing running and shined up, then flip it come summer for one of your other desires?

Cheers