Question about 1991 Honda NSR 250 MC 21
Firstly two strokes obviously do smoke because they use a petrol/oil mix to lube the motor,have you noticed any gearbox oil disappearing because a worn crank seal would cause the engine to suck oil from the gearbox ?
Posted on Feb 03, 2015
Difficult starting is a classic example of a faulty centre seal.The seals tend to harden up and leak after time and particularly with certain fuels.
Posted on Oct 24, 2013
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Power valves on different 2 strokes operate differently. A yamaha version does a self diagnostic because its a cylindrical type, so cleans off excess carbon. The type that the honda uses is a butterfly type and so a diagnostics / cleaning action is not performed on start up, but does require cleaning @ the recommended service intervals. See NSR-world.com for further info.
Posted on Jul 01, 2009
The bike may be discharging the battery. you need to test stator output,voltage regulator,and the fuses. Does the battery need to be recharged to restart?
Posted on Mar 22, 2010
SOURCE: fork seals gone on honda nsr 125
280 ml on the older models, and 320ml on the newer models.
1. you need to elevate the bike with a jack or something so the front wheel is off the ground.
2. undo the Allen bolt on the side of the fork, then proceed to take the main wheel socket bolt/bar out, so the the wheel comes off, the speedo drive will come off leave that hanging around lol.
3. take of the socket bolts attaching the brake caliper to the fork, dont leave it hanging secure it somewhere, so you dont damage the brake cable tube.
4.take handle bars off, one allen bolt on each one.
5. then unscrew the the 2 socket bolts that hold the folks on, if you follow the folks down you will see 2 socket bolts take them out. do the same on other folk.
6.then pull one folk at a time down, maybe tap it if its hard. and you will have the folk out in your hands.
7.unscrew the big socket bolt at the top of the folk out, but apply pressure, sometimes the bolt will fly off, so be careful.
8. take the big long plastic tube out along with the spring, and tip the folk upside down and pump it to get most of the oil out.
9.then go to the bottom of the folk and undo the allen bolt, when its moving around freely and not coming out put the spring in and push down and twist the allen bolt should come straight out.
10.pump it a few times and then you take the folk tube out completely and give everything a clean, it will be stiff when you get it near the top so get momentum and yank hard and it will pop out.
11. then the bottom pit of the folk that the tube goes into, if you look into it you will see the oil seal, take the cur-clip out and it should come out pretty easily.
12 give the folk tubes a rub down with fine sandpaper say 1000 grain or 800 grain, to get rid of little bumps, look carefully feel it with your hand, to see if theres any pitting, you will be able to see it, thats not good but make sure its not on the part of the tube which goes up and down the oil seal when compressed down.
13.put folk tube back in the bottom of the folk, then put spring in puch down tighten allen bolt.
14.put new oil seal on and push it down its best to use a oil seal hammer tool thingy, but if your careful you can tap it down with a hammer and something small and flat at the bottom, i used a bolt, worked well.
careful dont damage the oil seal.
15. put cur -clip back in, it should click, make sure its on the closest ridge to the oil seal.
16. put 280 ml, of oil or if you have a newer model 320ml, of fork oil in the tube, pump it a few times to get air out and oil to the bottom chamber.
17. put the spring back in and the long plastic tube, and put the top bolt on for now not to lose not to tight.
18. attach the folk to the bike again and same with the other one, make sure you align the little ridge on the top of the folk, with the top of the steering bar, the top steering the bar the folk go into last. its late lol getting confused lol. oh and when y0ou align make sure you tighten the bolts holding the folk in place.
19.then put the steering grips/bars back on and then tighten the top bolt tight cant remember the torque setting. then you know everythign from there. phew
Posted on Jul 20, 2010
Tips for a great answer:
Jan 02, 2016 | Honda Motorcycles
Apr 29, 2011 | 2000 Honda NSR 125
Oct 05, 2009 | 1993 Honda NSR 250 MC 21
Oct 05, 2009 | 1991 Honda NSR 250 MC 21
Aug 09, 2009 | 1992 Honda NSR 250 MC 21
May 22, 2009 | 1992 Honda NSR 250 MC 21
Apr 25, 2009 | 2001 Honda NSR 125 R
Jan 04, 2009 | 1993 Honda NSR 250 MC 21
178 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: