Rd125LC jetting advice needed please

[snowbound]

Hi guys,
I posted something similar to this on another rd forum but the mods have long since left so there no one to publish it, i hope someone can help.

Around 2004/05 i acquired a Rd 125 LC. It was easy transport at the time to get to work.
She was lovely little runner. and the smell of 2 stroke was far too addictive.
I started using a duel carriage way to go to work, when she got to 60+ she would bog down, now I'm not sure whether this was due to under or over fueling. So i just stuck to 30/40 mph roads.
I did burn through a set of piston rings, these were replaced and the bike was fine (damn powerband!).

long story short i joined the army and she went into storage.
Just left the army and I'm a little wiser, have my full bike license and understand the issues, as you will when i list the specs.

Specs:
Nikon exhaust
KN style air filter
6 mm spacer plate on reeds
+1.50 over bore
oil is pre-mix

These mods were done buy the previous owner, before she was stored i spend over a week trying to reset the floats in the carb, as the bogging down had got more frequent and sometime she was hard to start.
Not knowing about the jets, clip positions ect.
I purchased another carb off ebay, from a working bike, still had simlar issues.

So this leads me to jetting issues, i now understand that with filter and exhaust mods you need to change the jets to compensate for more air and a leaner mix.

Hope someone here knows there jets as i would love to have her screaming down the road and restored to her former glory.

Before she was stored:

[mellow]

hI M8.
I have a nikon on mine with the working powervalve. I run the standard airbox though and apart from that its pretty standard.
I had problems with low running and found THIS article. Carb problems are deciphered with throttle position,Not speed or revs.
Have a read of that article m8.should help you out.
Id ditch the K&n too

[snowbound]

Thanks for the info,
I have thought about ditching the k&n but i have no idea what the original airbox looks like.
Working powervalve, as in ypvs or something else?
The article is alot of help, i'll be getting her out on sunday all being well so we'll see what some fresh petrol and sunshine does.

Thanks!

[mellow]

yes m8 working ypvs
i went up on main jet from 195 to 210,about 2 sizes which is about right.
Airbox's are the same for all 125s and come up on ebay often

[snowbound]

Well, got her out today and checked the jets.
Main was 240
Pilot was 20

Is it just me or is 240 too much?

So today i stripped the carb and gave her a good clean (got the jet numbers)
washed the tank out with fresh fuel and put fresh pre-mix in.

checked the clip settings and pipes on the carb.

turned the fuel on and kicked her over.
Took a few kicks but got her running on the choke. Had to wait till she was warm untill i could turn the choke off.
Throttle was hit and miss, sometimes it would bog when there was less than a 1/4 throttle on, other times i could rev to 8/9k happily.

So thoughts guys?

[bertiemollie]

Did you take out and clean the emulsion tube?

I think 240 sounds in the right ballpark if you are running premix.

Do you have an airfilter extension tube?

[snowbound]

Emulsion tube is my next job, found a great guide on here for it.
No extension tube on the airfilter. How would the extension tube effect it?

[mellow]

id have said 240 was too big,but then i read ur specs again and may be right with k&n.plug chop is the test for that.
If its running shitty at small throttle opening its gotta be pilot circuit.make sure its clean.spray carb cleaner through it from all ways ie through the idle adjuster screw opening,then through bottom of carb where pilot jet sits and then through the two small holes in front of the carb just in front of the slide.You need to block some holes as you do this to get it going through the way you want if you get what i mean. Ul know its clean when you block the idle screw hole,spray the cleaner into where pilot jet goes and u should see it spray out of the 2 holes in front of slide.
Failing that you "may" need to change the pilot jet to smaller or larger using the test in that article but 20 is correct for that model as standard

[bertiemollie]

Have a look here.

I ran 220 in the day with a micron, K&N and ledar air kit and did have it running ok with 240. With premix 240 will not be far out with premix. If you do get it going please make sure you plug chop and check for plug colour.

rdlccrazy.proboards.com/index.cgi?action=display&board=80lc125lcchat&thread=8898&page=1

The running can be affected without an airfilter extension tube. I have one spare if you want for £5.

Cheers

Andrew

[snowbound]

Well well well. Good news on the front for a change.
She's back running again.
Stripped the carb down till there was nothing left to strip apart from the air mix screw for the pilot. All looked good untill i tried to take it out.
It was jammed in there and the previous owner had stripped the head to a mm of its life.
Had to hacksaw a new groove into it. Took it out cleaned it up and put it back in all the way and unscrewed it 1 1/2 turns.

Put her back together and kicked her over with the choke on. Not starting.
Turned the choke off and she started on the first kick.

Ran until i turned her off.
Chuffed...

[snowbound]

Thread from the dead but,

Could someone confirm from the pictures if this is indeed a MK1 engine.

Many thanks.

Dan

[jackup]

It's defenetly a mk1 side casing so that's the only real diffrents bet tween a mk1 an mk2 if it was a mk3 it would have a round head