rd180lc is no more

[perence23]

Just discovered that the life expectancy of an rd180lc is about as long as a worm in a pond :/. Iwas going down the A38 on the way back from matlock, at 8000 rpm in 5th and 80ish when the engine decided to seize. After 578 miles. Lovely :/

[twostroker]

Mar 20, 2011 17:46:16 GMT 1 perence23 said:

Just discovered that the life expectancy of an rd180lc is about as long as a worm in a pond :/. Iwas going down the A38 on the way back from matlock, at 8000 rpm in 5th and 80ish when the engine decided to seize. After 578 miles. Lovely :/

i expect the extra cc's wasnt the problem but more than likley the jetting or something......did you do a plug chop?

[perence23]

yes rejetted yesterday and it was fine. i have also took the head off today and that plug is still the right colour as well. So i have no idea :/.

[twostroker]

was the crank,mains,big ends all ok?
did you use a rd400 little end bearing?

[perence23]

we tried a High cc Rd one but carnt remember which one and it was too big. what fits in a standard 125lc con rod? Have got a disintigrated piston etc and metal in the engine that now sound ever soo gritty and rough :/

[twostroker]

Mar 20, 2011 19:53:07 GMT 1 perence23 said:

we tried a High cc Rd one but carnt remember which one and it was too big. what fits in a standard 125lc con rod? Have got a disintigrated piston etc and metal in the engine that now sound ever soo gritty and rough :/

there are rods and bearings better than standard but mine was fine with standard (re-built botton end,rd400 little end and a jap dt175 piston kit supplied by fahron.it could be many factors that caused it to pop

mine ran ran like it was being strangled and mega hot untill i brought a 1 0ff exhaust to uite the bike and set up properly on a dyno as after many jetting attempts i gave up just let a expert do it.mine produced 13bhp on 1st dyno run and 28bhp when set up with correct jetting.

[perence23]

Mine has an autisa kit. And according to fharon you carnt use a dt175 piston with it as the pegs catch on the exhaust port. So i used an IT175 piston. Mine ran quite well and but it wasnt as fast as i expected so i got it jetted and set all up properly the power increased by about a third, i couldnt belive the difference.

[tsa]

I run a Yamaha Blaster 200 cc piston in mine and its been running for 6 years now with no problems at all.

[perence23]

Rebuilding it asap be on the road again in 2 weeks .

It went well though before it went, on the way out it pulled 90 at 9,250 ish in 5th

Still couldnt keep up with my dads lc though :/

Got my bike test 17th april though :/

Thinking of getting a CBX250RS going to look at one soon. But i hear a lot of mixed reviews thought anybody had one?

[perence23]

Mar 21, 2011 0:54:24 GMT 1 tsa said:

I run a Yamaha Blaster 200 cc piston in mine and its been running for 6 years now with no problems at all.

Is yours a autisa kit or a resleved rd barrel? If they work with autisa kits i will invest in one tommorrow as im struggling to get a quality 1.75 o/s IT piston.

[tsa]

My kit is an autisa kit. I run a dtr125 clutch, Stronger bigend and a YZ125 Conrod, recut head to suite the piston and has not missed a beat since I built it.

[richardroberts]

best sticking with standed i think i have a mk2 with mk1 barrel, skimmed head and a micron ( the 1 with the endcan) and i had 92 y-day and it had abit more to give maybe 95 but was abit unstable at that speed

[lc king]

180 kits do work well, y have a 125 when you can have a 180?? they give so much more torque and you dont have to keep dropping gears as they will pull in top!! if the engine is built right , you are using the correct amount of premix and it is not getting to hot they last for ages!!! like any 2stroke make sure its warm before you thrash it!!!!!!!!!!!!!

[LC'Adam]

Sorry to hear perence, but me and gaz have talked about this.

My view is-

In the crosser world (where I originated from) it is seen as absurd to oversize the CC of any 125 2t machine to anything over 144cc. It is said that anything more than this and reliable performance is lost. Believe me, the motocross scene is seriously competitive and if there were an easy way of slamming more bhp from an over size 125 then I would know about it.

The cooling system among many other things is not designed to take the strain of this kind of punishment. Especially as the design of it (in the case of a rd125lc) is not meant for competition use and is over 30 years old!

Then there is the issue of expansion chambers (the design must be significantly altered to suit).

The further you stray from yam's original motor design, the deeper money pit you fall into.

I know, I have been there!

If you want to go faster, do your test and buy a bigger bike. Simple.

Don't get me wrong, I'm not ranting or raving by any means and I am all I'm 17 years old and all for 'tuning and modification' but I don't want to see you other lads throw money away like so many others have in the past.

There are more effective and reliable ways of getting more power without a bore kit.

Why push a 20 odd year old machine to limits it wasn't designed for even when new?

Better off with a modern RS 125 or better still a bigger machine.

Adam.

[perence23]

The reason i have the bore kit is because it came on it and i dont have a working 125 barrel.
It would have cost more to convert it to a 125 again as it have a massive carb etc that wouldnt run on a 125.

And plus rs 125's are terrible if i wanted one i would buy one but they dont have the appeal of an rd, I had an rg125 fun and they outclass the aprillas and it got half the looks of the rd.

Also i have my bike test on the 17th of april.

Bikes going to fharon for sorting out and will be ready soon i hope

[LC'Adam]

I wasn't having a dig at you perence and I totaly understand why you kept the bore kit on. Just wanted to make a point in general.

Its just my opinion and yes rgv 125 and tzr 125rr are the best 125 sports bikes ever made

However, I said aprillia because parts are more readily avalible for em.

Good luck with test and hope fharon can sort your lc

Adam

[perence23]

Its ok adam i understand what you mean. Its just the fact that i would like an rd, (even though i am tempted by the tzrr and thr rgv).
I was concidering putting a 125cc barrel as i have one on a different lc, but will that work ok with a dt125 powervalve carb? And i believe it needs a rebore piston etc. so we will see.