03 Ninja 250 Engine problems

[SabreValkyrn]

I've browsed most of the major Ninjette/Ninja 250 forums for knowledge before and for maintenance mods for the past 9 months, first time poster.

I am at least the third owner of a yellow 2003 Ninja 250. It has some fairing damage and 23000 miles. I've done 4500 miles of in town or freeway miles. I did a 500 mile trip and... apparently the bike was eating oil and I didn't notice. TL;DR, 70 miles from home 5 lanes over from an uphill off ramp, my engine died.

Mechanic says the seals around the pistons are very unhappy, but he hasn't taken it fully apart. We had compression earlier, but it sat inside for about a week before he could look at it. Now it has around 40 (insert applicable units) compression when he drops oil down the piston, but nothing when it is dry. The mechanic bill is $100 so far.

One mechanic said I could part it out for $1000-$1300, the one I trust more said it needed pistons and rings. From what I could find, it looks to be a day of labor and <$200 to fix.

60-91.2MPG at 4500 miles has broken me even with maintenance/accessories (seat cover, double bubble windshield, and tank cover). I live in the greater Seattle area. I would prefer to get a Ninja 250 with lowish miles on it, the new-gens look pretty sexy and seems to be a bit better for passengers. I primarily use the bike for school<->work<->Seattle/Bellingham (80 miles).

Would people suggest I buy a used part and crack it open myself and try to fix it, learning a lot while doing it... but pain in all the things, have a mechanic fix it with a used part, or sell/part it and get a new(er) Ninja 250? Working, school full time, and busing 16 hours a week SUCKS. I cut my 2h 20m bus trip into 25m on a bike.

Any help is appreciated,

Joel

[Racer x]

Replacing the pistons and repairing the head will not be that bad. But the mileage is high and you have to decide. How are the tires chain general matinance? Sounds like you don't have time to rebuild a motorcycle. I would get a used 2008~2012 and then Try to sell your broken bike.

[FrugalNinja250]

If the engine siezed from low oil then it will run much more to rebuild it than to install a used engine.

[SabreValkyrn]

Thanks for the replies,

The tires have about 5000 easy miles on them. Chain and Sprockets were replaced 4000 miles ago and have been Chain Wax'd every 160 miles. Mechanic said they were looking really good still. He took off the valve covers (I think?) and said everything he could see looked in good shape (rockers, cams he mentioned specifically)

How much do you think I could get for it?

[7oxSin]

in the on season no more then 1200, right now i would say 800ish. i slapped a used engine in a 01 once, it cost me 250$ and still to this day runs fine, i sold the old engine with busted rocker arms for 100$ on craigslist. the add said that it had the broken rocker arms and dude still bought it.

[SabreValkyrn]

Thanks a ton! Your replies helped me narrow down my decision.

I think I have funds worked out to get a 2008+ Ninja fairly soon.

Since the engine doesn't work anyway and I plan to be riding until I physically can't anymore, I want to take a crack at rebuilding the engine with some friends. What's the best-case cost for rebuilding the engine ourselves?

My thinking is: It doesn't work, so I probably can't make it worse. Seeing and knowing how the engine is put together would be a good experiment/learning experience. And I would love to give it to a buddy of mine if we get it fixed.

[02337]

I've never torn down a bike engine but if it's anything similar to a car engine. Should be removing the head, depending on how bad it is, honing cylinder walls, replacing piston rings, rod bearings.

Like I said I am in no way saying that is all but when I tore into my first bottom end of a motor I just kept everything simplified in my head. Don't over complicate it, I'd get a service manuel a good torque wrench and other than that most basic hand tools should do it. After you crack it open and get the mystery out of a engine it really losses the fear factor. Good luck!

[AlexL]

Much cheaper to just get a used engine. Another thing that can happen to these motors when they are higher mileage is spun bearings. If you go through all the trouble to replace the pistons and rings only to have a bearing fail you're not going to be too happy. Labor and parts for a motor refresh that extensive is going to cost way more than just putting a low mileage engine in.

If you're just wanting to take it apart to see what's wrong and learn about it, then knock yourself out.

[SabreValkyrn]

I'm getting an engine from Phyberoptic.

I do want to tear apart my old one to look at it though. Any rebuild guides or pointers?

[bdavison]

Here's the thing.

If you ran it out of oil, and it siezed up....this is probably the only time I'd say pull it and get another motor.

Minimum, you are going to need new pistons and rings. More than likely, you will have to replace the pistons, rings, and.....

Cylinders, because they either got scored by the seizing pistons, or warped from the heat of no lubrication. If you are fortunate, just bore them out and get oversized pistons and rings. If you are extremely fortunate, you might be able to just hone out any minor scratches or gouges.

Crank bearings, no lube means they self-destruct very rapidly, along with cam journals, and other bearings.

Probably going to have to do a flush of the entire system, because of all the metal particles from self-destructing parts that infest your oil passages, and what-not.

Now this being said...By all means, take the thing apart and see what damage there is for three reasons. 1. It will teach you a lot about the engine so that future repairs will be a piece of cake. 2. You might be able to fix it, and then either keep it as a spare or sell it off and re-coup your money for the replacement motor. 3. Worst case scenario, you can part out what ever usable parts you can salvage off it, and still gain an education in engines.

[SabreValkyrn]

Thank you very much for the explanation.

Where is the engine thermometer located? When the engine lost power, the gauge was less than 40% hot. Does that mean any manner of good news?

[phyberoptic]

Originally Posted by SabreValkyrn

I'm getting an engine from Phyberoptic.

I do want to tear apart my old one to look at it though. Any rebuild guides or pointers?

So, you really won't need the mechanic to replace the engine.. It's like 4 hours start to riding down the road. (1st time)

You had a running bike so I'd not even go through the carbs.

Take off the tank. drain the oil and coolant. Remove the radiator (and lower coolant hose), exhaust, remove the sproket cover and front sproket. Hang the chain out of the way. Losen the upper coolant hose on the top of engine, remove the spark plug wires. remove ground wire and unplug the charging system wires. losen the carb boots. remove lower engine mount bolt. Remove upper engine mount bolt. place 2x4 under engine as a bumper. pry engine forward from rear upper mount point which will pull the carb boots loose, and allow engine to swing forward on front mount bolt axis. remove front engine bolt. pry front of engine lose from front mount sliding rearward on 2x4 and catch engine. Muscle free engine out of way ~95 lbs.

repeat in reverse... may need a jack or helping hand to get it up (the engine).... ;-)

check coolant level and oil. Maybe change the oil filter before refilling.

turn key, ride off into sunset with big grin and a few bucks in your pocket.



---------------------------------------------

Now, pop the valve cover off the old engine and look at the cam lobes... and check the cam chain for taugntness. push a rag into the cam chain valley so nothing falls into the bottom end. Make sure none of the rockers are broken or cracked. remove cam supports, rockers and cams. then head bolts (5) and bolt holding head from bottom of cylinder. remove oil line to head, and chain guide. head should tap loose.
inspect valve heads for damage. You'll likely be lapping the valves at the least with that many miles.
Inspect piston tops for any holes burnt in..

Pull cylinders free and inspect inner walls for scoring, cracks or other defects. Bad cylinders mean tossing the jugs as you can replace the entire setup for less than having a sleeve replaced will costs.

If they look good then mike them for size (wear) and round. Again if worn past a couple of thousdandths toss and get a low mile cylinder set with matching pistons.

pull piston retainer rings and pop em loose. Inspect for defects and check condition of rings. If good, soak in parts cleaner bcket to clean em up.

rotate bottom end to estimate condition of bearings... If top end was in good shape this is where the problem is most likely to be, but you would have heard crunchy-ness back when it was running. Check filter and basket for metallic rubble... sign of spun bearing or rocker arm parts you didn't find earlier.

If bottom end is hosed... shop for newish bottom end and rebuild with your top.

If you are not going racing and just want to piece together a nice runner, used replacements is best bet... new parts will kill you in costs.

-=PO

[phyberoptic]

Originally Posted by SabreValkyrn

Thank you very much for the explanation.

Where is the engine thermometer located? When the engine lost power, the gauge was less than 40% hot. Does that mean any manner of good news?

There is a sender screwed into the radiator on left hand side.

What did the Oil pressure look like before failure?

-=PO