Carbs, Jetting, Performance

[Henriettaah]

Hello there

The LC is a 125, and has a wicked powerband on it.

However, getting there is another issue!

What I really want to know is: is there any way of getting the rest of the rpm to react somewhere near that of the powerband...

4k rpm is pitful. She really struggles to get past there. Its a struggle to get up most degrees of incline beyond 30°, be it in first or second ! !

What can I do here? While I'm not familiar with the 'power' (cough) of 125's, I feel that what the LC does have at lower rpm's is distinctly lacking, and feel it should get up to speed sooner than it does. It was a struggle to get up to 30mph at some points last night!!

It has an Allspeed exhaust on which I understand can affect the lower end performance - but to this degree???

[9000white]

all your questions about the LC can be answered here.


http://rd125lc.proboards25.com

[BuzZz]

If your jetting is correct then it is possible what your feeling is about right. Single cylinder 125 2-strokes have never been know for bottom end power, and those with performance pipes even less so. But jetting can aggravate the problem sometimes, so be sure it's as close as you can get it.

The way around that is to keep the RPMs higher to keep the bike in the meat of the powerband. If it's slow to respond when you open the throttle, back off a split second, bang it down a gear and get on it again. They call 125's 'Screamers' for a good reason.

[Henriettaah]

I wanted to update on this !

There were major problems after the rebore had settled, and discovered these were due to massive over-lubing (recommended settings on the pump: between 8 - 11 thou of an inch. Actual: more than 23 )
Once this was reset (using, in fact, a household washer - rather than loads of micro-thin Yamaha shims of around £1 each) things were massively different! Before, bike close to being set on fire and beaten with a wrench. After, practically brilliant

Then there were stuttering problems when the engine was under strain - it felt like fuel starvation, somehow. After chatting to someone - and checking the size of the main jet, which was a teeny 160, compared to the spec in the book which is 190 - I've put a new main jet in which is a 210.

Went out today and I really enjoyed the ride - which is more than can be said for the few hundred previous. Also, enjoying leaning over through the corners more and more - and everything staying coool, Daddy-O ! !

Come on, the summer...

[storysunfolding]

Come on, the summer...

Glad it worked out for you and I can't agree with you more!