Hi all. Just bought what looks like a 92 NSR250SE. However, closer inspection is beginning to reveal that it's a bit of a 'bitza' (as in bitza-this bitza-that for non-Brits)

Just gone over the motor looking for id numbers etc. so am hoping some of you more seasoned NSR types can give me some ideas as to exactly what it is...

OK, first up: WET Clutch Engine no starts with MC16E - does this indicate that the motor is from an earlier MC16 model? Black sticker on the clutch cover has KV3-700 at the bottom

Lower cylinder has the faint stamp 1A12 274 along the outside bottom edge. Upper cylinder is similarly stamped: 1A11 057. Bolth cylinders have L1 stamped on them too

- Lower head is marked KV3L FR1. Upper head is: KV3LFR2

- Left hand carb is marked TA 22BAFD4 on the lower edge of the main body

Any help with Identifying the origin of these parts greatly appreciated.

It looks to have been messed around with quite a bit generally and I am trying to get it to something like stock and running well before I do anything else with it. I need the following bits if anyone has spare ones kicking around they want to sell (or can adcise on the best source of them).

The 3-way connector that I assume is part of the power jet plumbing (still working this NSR stuff out so please don't snigger if I get this stuff wrong ) It fits between the left carb and the power jet solenoid (I think it's a solenoid )

Lower cylinder head coolant hose (mine's split slightly from overtightening)

Front tank mounting rubber

Rear light lens

There's a little round gizmo on the front underside of the airbox. I'd imagine this is supposed to be connected to something, but I know not what? And mine just has a short opaque plastic tube sticking out the bottom? Any pointers? What's it for?

OK. I'm sure there'll be more as I delve deeper into the bowels of the thing, but for now I'd really appreciate any help/pointers with the above to keep me going. It's a lonely old business

TIA

Wb

firstly L1 barrels looks like its form a SP bike, L heads again SP heads, the wet clutch could have been changed SE/SP should be Dry clutch, ALL mc21 engine numbers start with MC16 so dont worry, Have you looked at the TYGA web site for some of the bits you need?

Thanks rc46

Maybe it's not so bad then? I thought I had an older motor lashed into a newer model chassis.

Are there diff's between SP and SE models in terms of porting etc? I am more familar with Yam's - esp' the TZR 3XV (got four of the blighters - bit of a sickness really ) With the 3XV, SP top end parts are quite significantly better spec than the base 'R' models. Is it a similar deal with the NSR or am I now getting unduly excited?

Cheers

Wb

Unlike the 3XV, there's no difference in the porting of the MC21 SE/SP & R, but the overall height of the barrels differ slightly, as do the combustion chambers in the heads, so don't mix them else the extra compression is usually enough to push them over the edge.
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Andy.
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So what suspension does it have? Is it adjustable in anyway? This would point to it being either an SE or R model.

As for the "little round gizmo on the front underside of the airbox" you may well be referring to the petrol overflow pipe. The top of the airbox has a square 'receptacle'. This has a drain formed into the bottom. The drain should then connect to a hose that works it's way out next to the rear sets. Check the bottom of the petrol tank....you'll see a little overflow pipe that lines up.

Thanks for the pointers fella's -

The suspension is the fully adjustable type, so I'm assuming it is a pukka SE model?

The air box thing i'm referring to is seperate to the fuel overflow bit it's near it tho'. It has a piece of small white/opaque hard pipe poking out of it and can be blown through. I'm assuming it should connect to something or that there is maybe a bit of the aribox assembly missing. I'll try to get a pic later so that I can post up the offending part for analysis.

can anyone offer any pointers on the parts I need? I Particularly need the powerjet '3-way' connector as I have made getting the powerjet sytem back to stock set-up one of the first on my list of jobs to do. I will be trying my best to make get this bike running and riding as well as it can because currently it doesn't feel right at all and i'm sure it should be much better than it is.

Another quicky. Can you normally see the edge of the reed valve block gaskets? I can't see any and suspect there may not be any in there at all as I see the tell-tale sign of gasket goo... I supsect it may be sucking air somewhere as the idle speed is pretty erratic and I'm hoping the leak is in the intake rather than at the crank seals...

Cheers all

Wb

wb wrote:Thanks for the pointers fella's -

The air box thing i'm referring to is seperate to the fuel overflow bit it's near it tho'. It has a piece of small white/opaque hard pipe poking out of it and can be blown through. I'm assuming it should connect to something or that there is maybe a bit of the aribox assembly missing. I'll try to get a pic later so that I can post up the offending part for analysis.

can anyone offer any pointers on the parts I need? I Particularly need the powerjet '3-way' connector as I have made getting the powerjet sytem back to stock set-up one of the first on my list of jobs to do. I will be trying my best to make get this bike running and riding as well as it can because currently it doesn't feel right at all and i'm sure it should be much better than it is.

Like this?...



A hose should come from the top joint of the X piece (have a look in the carburettor section to see an example of the HRC red X piece) to the underside of the airbox and this opaque 3-way joint. The joint presses into a little filter that is pressed into the airbox. The tube from the joint/airbox then runs to the inlet (bottom) connector of the air solenoid block.

wb wrote:
Another quicky. Can you normally see the edge of the reed valve block gaskets? I can't see any and suspect there may not be any in there at all as I see the tell-tale sign of gasket goo... I supsect it may be sucking air somewhere as the idle speed is pretty erratic and I'm hoping the leak is in the intake rather than at the crank seals...

There should be a gasket between the reed blocks and the crankcase, but not between the manifold and the reed blocks as there is a rubber coating on the manifold.

The manifold can distort though, so it's worth checking there for an air leak.
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That looks like the fella Andy. Although all I have of it is this:



I'd been wondering where my 3 way joint was...Do you know where I could most quickly source one? Are the dimensions of the joint and the bore of the pipes used critical? If not i may be able to lash something up for the time being, as i'm keen to get everytrhing as close to stock as possible befor I strat ripping the motor apart to try to find why the damn thing vibrates so much. I think I have the powerjet plumbing amost back to stock. see below:



Any corrections welcome...

The hose marked with Yellow was missing when i got it. I've put the new piece in and joined it up with the Y piece as shown on the airbox lid, but I was less confident of the routing for the 3 way bit, but I think you have cleared that one up for me.

I started it up again last night without the airbox in place but it is still very vibey and has a very erratic 'tickover' - start up and it'll run fairly cleanly at about 1300rpm now that I've sorted and matched up the air screws, but blip the throttle and it may only settle back to 3500rpm or so. Blip angain and it may settle the back to 1300 - or not depending on how it feels The throttle slips while not returning quickly enough for my liking ar not sticking open or anything so i'm thinking probably air leak somwhere. It aklso spits back a bit through the carbs and has a very sharp (almost 'clattery') engine note. It's not like big ends or anything - it just sounds 'wrong' Are they prone to losing bits of piston skirt or anything like that? I'll prob pull the reed cages out and the pipes off to see if it's more visible then before I pull the cylinders to check.

Thanks for the help, fella's. I'll keep at it.

Wb

I've probobly got the bit you need on one of my spare NSRs. I'll send it to you....you can then replace it at your leisure. PM me you address.

You seem to have a front head on the rear cylinder in the picture above.

Chester362 wrote:You seem to have a front head on the rear cylinder in the picture above.

Ah... My understanding is that it should be the other way round for best performance, shouldn't it? ie: a rear head on the front cylinder...

Heads on it are marked thus

Front (lower) KV3L FR1

Back (Rear) KV3L FR2

Can anyone confirm if they are just on the wrong way round? Or has someone in it's past life swapped the rear head for a front?

Could this have any bearing on the generally poor performance of the bike?

Cheers

Wb

Basicly for performance you don't want a front head on the bike at all.

Both heads want to be the ones with the centrally located plug.

re. poor performance;
if someone has used a front head on the rear (either on purpose or not) of an se/r hybrid engine in an se chassis it's probably had some real problems in the past and they've just done enough to get it running and that's it, hence not set up too well and poor performance.

I'd get it back to standard (including the jetting), All the info is on the site, just set the bike up as it should be with the powervalves set right, all hoses etc properly connected, a rear head on the rear and a front on the front and a standard airbox. It should then run like a dream, they're really nice bikes to ride in standard form, vastly better than the RGV of the same generation. Then you can take it from there if you so wish.
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not the best shot, but here is a rear head on the front, as ive done the change, but again make sure the heads match your barrles. both L

http://www.bikepics.com/pictures/479586/

Thanks for the help, fella's. Please keep it coming as I really do appreciate it

I'll keep chipping away at the various jobs and hopefully get it all sorted over the summer. The cycle parts and rolling chassis generally is in very good condintion for the year, so hopefully when I get all this other stuff sorted it'll make a nice bike - gotta stay positive .

Rgds

Wb

PS Anyone got a pair of front KV3L heads for sale? I think I saw them on the Apex leisure site for 60ish quid each. Does that sound right? Seems pretty reasonable to me

You mean a pair of rear's surely?? You've got front's already and everyone wants rears so you'll be lucky to find them second hand.

You also need a new hose and a stud or two to do the rear head conversion on the front (or the rear in your case), Apex or Tyga can supply a "kit", don't wory about the claims the front wheel will foul the std plug, it's all lies to sell you a £60 plug and cap.
And it is advised to run the .6mm base gasket on the front cylinder if you run the rear head.

But I really would get it back to standard first and running fine. That way you've got something to work from. If it's not standard it puts more stuff in the mix that could be wrong.

If I were you I'd get the rear head right anyway, that needs doing. Some one will have a lower std front head hose lying around, I gave mine away at Oulton, sorry You'll also need the std rear hose. Ask in classifed ads.

Get the carbs off, check the jets are all std sizes and they're not gummed up, while they're off check the reeds are OK, do the reed block gasket if you're concerned about it, they're not expensive.
Check the power valves are adjusted properly details here and make sure all their plumbing is correct.
A pair of new plugs and some fresh fuel and it should run perfectly, if it doesn't find the fault, coils, stator, dodgy PV servo or whatever.
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