Some questions about my new bike!. (honda nsr)?

Question

1989 honda nsr 125. 11,000 on the clock.

1, When i push the bike when it is in gear, it is very stiff to move even though the chain is at the correct slackness. Other bikes ive had, pushing them forward in gear with the clutch in, has usually been as easy as pushing in netural.

2, the exhaust smokes more than my previous bikes, i think it has been sat for a while, hence the early model to low milage ratio. what can i do to lower smoke?

3, there is a slight bit of rust inside the tank, what is the best method to get it out without removing the tank and replacing it?.

4, how do i check the tread on the break pads, when they are disc breaks?.

5, ive heard of something called "carb foam" that you put in the tank of your bike to clean out the carbs instead of taking them apart. What is the prcedure?

thanks

Answer 1

Sarah,

The first answer was reasonably comprehensive but fairly obvioulsy North American based as Sea Foam is not generally available outside of there. Are you in N America? The other point is that the 1989 NSR125 is a two stroke and the smoking issue may not just be a case of cleaning out the carbs. The first thing to do, as it has been sitting, is to take the bike for a d**n good thrash and really get it up to temperature. Two strokes, especially of this vintage, can smoke when cold but very often giving them a good run can help blow out the crud that has been sitting around  - so hop on it and give it a good fifty or sixty mile run, including some full throttle openings once it has warmed up of course. If it still smokes after that then you will really need to solicit some more in depth help or if you are mecahnically competent then look at the two stroke oil pump to ensure that it is set correctly, check all the carb settings, whip the head off check the barrel and rings, the crankcase seals could well do with checking, perhaps a bit of a decoke would not be a bad idea. There is every chance that the exhuast has old oil soaking up the baffle which won't help either. This may sound daunting but don't worry too much the benefit is that these little engines are not a huge job to work on.

The pushing of the bike in gear has been answered - it is most likely your clutch needing adjustment.

You basically can't remove the rust from inside the tank without taking it off. The previous answer was good but  many people actually use paraffin to slosh around the tank with the nuts etc. There is a product available in the UK for sealing the inside of petrol tanks, the name of which I can't remember but Google UK "petrol tank sealant" and you will find it. I have used it myself, it works well but is bloody messy if you spill it. You do not want to have rust floating around in your tank, getting sucked down into the carbs and causing all sorts of issues, so take it off and get it sorted.

Brake pads are held in with a couple of pins and are easily removable for checking. To be honest if you are asking this question then I guess you would be best served to find someone who can show you how it is done and then the next time you will be able to do it yourself. It is easily done but also easily screwed up if you don;t put them all back together properly. The minimum pad thickness will be detailed in the Honda or Haynes manual (buy one) and is easily measured. It is the thickness of the friction material that is critical. Don't wait until you can see rivets or anything like that, change them before then as any squealing indicates metal to metal contact which knackers the discs up pretty quick.

I am not a big believer in putting things in the petrol tank of a bike and running it through to clean engine components but I accept that I am in a minority there. I would still suggest that if the bike has been sitting for a long time that you get the carb whipped off and checked over.

Answer 2

your clutch may be draging slightly,simply readjust..

2 stroke mixture on pump may need setting..rather smoke than none.

petseal will seal the tank and stop it rusting anymore

you can see pad thickness if you look along the length of the wheel.

forget carb foam...justrt remove and clean the carb...its the best way.

Answer 3

I can't add anything to that!

Answer 4

You've organized the questions pretty will, so I'll try to answer in the same way.

1. If it drags when the clutch lever is compressed, and if it wants to creep forward with the clutch in a lower gear, figure on adjusting the cluych and clutch cable. Do it soon, or you'll have to replace it.

2.  Clean out the carbs, it will get better mileage too, with clean carbs.

Go the the autoparts, store get 2 cans of Sea Foam, and a new set of (iridium, if you can afford it) sparkplugs for the motorcycle.  

DRain the tank down to about a gallon of gas,

pour in a whole can of Sea Foam. Ride it around for about half an hour.  It may be worse, (more smoke because of the Sea Foam) and then park it over night. The next day, and the next do the same, until you run out of fuel. Pour the whole second can into the tank. fill it up. It ought to be like new, if the problem was varnished carbs.  When you get back home, replace the spark plugs.

3. Rust is caused by water in the fuel or trapped in the gas tank a long time, so the best thing to do would be to keep it full. If you want it out NOW, drain it dry, get a handfull of stainless steel nuts and short bolts, drop them into the tank add a bit of varsol (a non explosive solvent) or diesel, and shake it, until the tank is clean, and the solvent is dirty, if it is clean enough empty the nuts and/or bolts from the tank, fine, if not shake it some more.

When it is clean enough get you a product vcalled Kreem, come in a kit to do a single tank. Follow instructions on the tank TO THE LETTER.

4. You don't want treads on a brake, just look at the thickness of them.  When they get down to the bottom of the apparent thickness, watch the disks closely for signs that a rivet top has apeared clear of the friction material. Change them immediately.  If you don't want to take chances eating up your disks, when you feel like the brakes can't be used any longer, replace the pads.  When you have a service on your brakes, drain the fluid and replace it. It should be clear, clean, not yellowed or dark like used motoroil. Those are signs that you left it too long, and the water trapped in there will wear out/rust the wheel cylinders. (brake fluid is EXTREMELY Hygroscopic.  It absorbs and retains water from the air. So only use fluid from a sealed can. Water is the enemy of brake fluid, It tends to boil at a lower temperature than the actual fluid, so your brakes will exert less friction while going down steep hills, than with pure brake fluid.

5. Already answered.