honda NSR 125 problems

[woodie]

Hi

Iv owned my nsr for 10 years and itsw not been run for about 4 years as i blew the gear box...

i picked up a engine fairly cheap and threw it in there...
the bike had the exhaust restricitor out and the air intake one out...
iv never jeted the carb tho...

now im finding the bike has no guts at low revs hardly pulls i have to clutch it in the "band" to get it to pull me...
i took the carb off cleaned it with carb cleaner and checked needle postision all seemed ok...
it seems to rev from 1 - 5 k then gurgles/pops to 7 then the vlave kicks in then wont rev over 10k .....

iv fitted carbon reed valves when fitting the engine...

it just sounds very "air" as in if i open the throttle fully it dies off unless i clutch it in to the band,,

dunno wether to try jets unless anyone else has any other ideas im open ti anything as im really stuck !!

cheers

dave

[hramos]

[woodie]

hi thanks for the reply..

How would i go about checking the cdi ???

what are the symptoms of a worn CDI ??

[karthead]

Check how much spark your getting.

Also, it may be a mixture problem, i suggest you do plug chops at idle, 1/2, 3/4 and full throttles.

[woodie]

Thanks

gonna check spark ina mo i fitted a new plug when i put the engine in..

I do think its more of mixture prob as iv not jetted the card seems like not enough fuel or too much air


plus today there is fuel all over the floor like the floats are stuck...

bikes doing my head in gonna bin it

[MarJay]

worn CDI... what nonsense.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Vincent]

[stevo as b4]

It sounds like a it needs nothing more than a hour or so of dyno set up time and some re-jetting tbh!

I'd check for air leaks all over the induction system, engine gaskets and the exhaust port gasket. And strip and clean the carb properly. Get all the jets out and check the sizes against the factory spec sheet. clean the carb with a carb cleaning spray and or an airline. Is the float height correct?

lastly check the fuel tap and fuel filter is clean and that fuel flows as expected.

If it starts and idles fine i cannot see a CDI box being a potential fault in any way that is affecting the way the bike runs.

[skatefreak]

Have you checked the power valve?
Is it assembled/installed/functioning correctly?
With the power valve open @ low revs you will find bugger all power until you hit the band (makes roundabouts fun!) so could have something to do with it...

Also, been through many CDI's, ignore these idiots, changing the flint never makes any difference...

[Usher4566]

Carb leaking sticking float valve
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New cd200 benly owner

[Boydy]

probs a carb problem. buy these and stick them in, give it a good clean and i bet it's fixed

https://www.dellorto.co.uk/merchandise/products_details.asp?PartNo=NSR%20JET%20KIT&CategoryID=2&PartsectionID=24
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NSR 125

[woodie]

Thank you all for your replies ....

So i took the carb off and stripped it ...

the float were stitting low so i adjusted them up a little ... leaking fixed...

i then decided to check the reeds as the guy i got the engine off said he put carbon boyston reeds in ...
sure they were there but the white oval fuel flow block ...was not ...
so i put the stock reeds back in with the block...
i checked the valve assembly out and all seems in line...
and is kicking in a 7-8 k ...

so i put it all back together and blasted it down the road...

well....i deffo seems to pick up no more gurgling at a 5-7 k

BUT

still wont go over 9.5k revs
almost feels it needs more fuel.... or the valve is not fully open


Iv order the up jet kit from the carb site this morning
im gonna wack that in there fisrt ...

then ..i dunno what lol

thanks for all your help guys still open to any ideas

[Boydy]

Glad you've got it working well again!
Some models of the bike have cdis that limit the revs (or do something to ignition timings, I'm not sure :S) to about that. I've got a feeling that the french one does pretty much what you are describing.
It might be worth checking if you have a full power cdi unit.
The ci626 is full power.
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NSR 125

[woodie]

see iv never had that problem before its always rev up to 11 .....ill see how it goes with the jets in.. cheers boydy

[woodie]

RIGHT !!!

LOL it was me being a dumb ass when i put the block in i put the power valve cables the wrong way round.... yeah silly mistake

so i stripped the carb and put the jets in anyway as they came this morning.....

now i cant stop fuel over flowing out...

iv tried cleaning the needle valve

tired adjusting the float leval just cant stop it ....or flooding the carb out...

bikes ready for the scrap heap i swear loosing my head with it now.

[woodie]

ok

one of the floats has liquid in ......do the nsr ones have these in to balance the float or is it fubar ???

one float is filled about half way up tried shaking it out and so on ....nothing .....

cant find anything any where saying it does have a liquid balance

[Usher4566]

Is the carb missing or has it broke .there is a little brass tube cumming from bottom of float bowl ? Over flow tube .
____________________
New cd200 benly owner

[woodie]

sorry mate i dont understand you ..........

[Usher4566]

Is the bras tube that's connected to bottom of float bowl broken or missing .also is screw at bottom of carb tight
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New cd200 benly owner

[woodie]

yes and yes mate .......

there is liquid in the float im trying to find out if they have a liquid as a balance but no luck yet ....

think the floats naffed

[Triumph1300]

Floats don't as a rule have liquid in them.
It's flooding because of that.
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BWJ
Back on a BMW R80RT
Punctuation - the difference between knowing your shit, and knowing you're shit

[woodie]

just as i thought................ new floats it is then.....

cheers