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mad_max
21st March 2012, 14:08
Can a nsr250 be run on premix? Have heard there is a oil line somewhere which takes oiul from the tank and cant be used as premix.

Probably just a roumor but want to make sure

Need to know asap

Cheers
Crasherfromwayback
21st March 2012, 14:18
Can a nsr250 be run on premix? Have heard there is a oil line somewhere which takes oiul from the tank and cant be used as premix.

Probably just a roumor but want to make sure

Need to know asap

Cheers

I'm sure you'll find it's fine. Just make sure you block the oil line off so it doesn't suck air.
F5 Dave
21st March 2012, 15:10
Some bikes directly feed crank bearings etc, particularly Suzuki & require crankcase mods to run premix. Nor so sure on 'onda. Running oil in the fuel will make your air to petrol mixture leaner which isn't always a good look on a hi performance 2 stroke, so jetting up may be in order.

NSR world will have better answers.


So for track use? on the road it will be a drag mixing.
Crasherfromwayback
21st March 2012, 15:24
Nah...the NSR's are fine pre mixed.
imdying
21st March 2012, 15:39
There is no good reason to, but you can. 30:1 will be fine. Unless you're using it on the road and you plan on spending minutes at WOT. You will need to modify the pump slightly. Nobody I know of any note bothers, even when racing. YMMV.
gammaguy
21st March 2012, 15:56
one question.

why?
Crasherfromwayback
21st March 2012, 16:19
one question.

why?

If you're racing it...for safety reasons. I had two oil pump failures on my KR1's, and one of them threw me on my head going into turn 1 at Puke. Not cool. But from what I've heard/seen...NSR's are pretty reliable on the oil pump front.
mad_max
21st March 2012, 17:50
Its a mates bike and seems to be over oiling, just want to mix some up and see if thats the problem
Just want to try it. Could over oiling be a reason for it to be fouling plugs? Within a few rides?
Crasherfromwayback
21st March 2012, 17:55
Its a mates bike and seems to be over oiling, just want to mix some up and see if thats the problem
Just want to try it. Could over oiling be a reason for it to be fouling plugs? Within a few rides?

Maybe. It's not sucking oil out of the transmission is it?
Latte
21st March 2012, 18:02
Maybe. It's not sucking oil out of the transmission is it?

This, mine was fouling the front cylinder, rooting a new plug every week.Remember Rick Porter telling me to ride it harder, keep it above 7 :crazy:
Crasherfromwayback
21st March 2012, 18:10
This, mine was fouling the front cylinder, rooting a new plug every week.Remember Rick Porter telling me to ride it harder, keep it above 7 :crazy:

Lucky it wasn't an RS 250 then. Plugs back in the day for them were over $200.00 a pop!
SMOKEU
21st March 2012, 21:00
Lucky it wasn't an RS 250 then. Plugs back in the day for them were over $200.00 a pop!

What happens if you run them on standard NGK plugs?
Crasherfromwayback
21st March 2012, 21:08
What happens if you run them on standard NGK plugs?

You couldn't. The front tyre was too close to the front cyl and would tear them in half with suspension compression.

They were (at the time) special stubby HRC only plugs. Made doing plug chops fucking expensive.
Latte
21st March 2012, 21:11
Lucky it wasn't an RS 250 then. Plugs back in the day for them were over $200.00 a pop!

I thought 20 bucks was bad enough. Ran them on plain e plugs to save bucks. Never noticed a difference.
Crasherfromwayback
21st March 2012, 21:14
I thought 20 bucks was bad enough. Ran them on plain e plugs to save bucks. Never noticed a difference.

I guess they thought any cunt running a GP bike could afford it/wouldn't mind. They were wrong on both counts!
imdying
22nd March 2012, 11:19
Its a mates bike and seems to be over oiling, just want to mix some up and see if thats the problem
Just want to try it. Could over oiling be a reason for it to be fouling plugs? Within a few rides?I can probably find you a copy of the service manuals for the NSR in English, and with that you should be able to check the pump adjustment pretty easily.

Most likely she's just worn out. But that's not such a bad thing... rings and pistons are cheap and easy to fit (use OEM gear, not Chinese knock off rubbish)... at least it hasn't been neglected so far as to die.

Start with the simple stuff... two strokes like to have all of their adjustments correct (ok, all bikes do, but four strokes are happier to run like neglected dogs).