The bike seem's to be running half decent most of the time but then there's times when it's totally gutless!! I got in touch with our now retired ex-Honda dealer who has basically serviced this bike from new. He tells me it needs de-coked. I believe its a bit of a pain to strip the bike down so the carb can be stripped/cleaned and basically not worth my while doing it he thinks, (i have my bike test again in 4 weeks) I know nothing about mechanics at all so doing it myself is out of the question.

Is there a quick fix to help clean it out? Maybe a fuel additive or something i may be able to pour/spray directly into the carb? I was told Redex would be useless. I think i can get some access to the carb by removing the vented section from the fairing. I intend to use this bike for my test so could do with making sure my test day is not the time its running bad


Cheers

I'd be surprised if it needs a de-coke unless it's done big miles (20k-ish) or has been run with the oil pump set wildly rich or running on lawnmower oil.

De-coke refers to cleaning the build up of carbon in the cylinder head, piston crown and exhaust port. This occurs naturally by burning petrol but is increased in two strokes as they inject oil directly into the combustion chamber as well. But modern petrols and oils create much less carbon than they used to.

Also cleaning the carb will have no effect if it does indeed need de-coking. there shouldn't be any carbon in the carb unless something's seriously wrong.

I'd guess it just needs a routine service - new spark plug, check the connection on the HT lead/plug cap is sound and get the carb and oil pump set up properly. Couple of hour's work at the most.

And get a different mechanic!

Better still, get one of these Service manual and do the jobs yourself, 2-stokes need regular maintenance but it's all simple! A beginner can do it - I did!

fastfitter - the bike has 38k miles on it. It actually belonged to my brother before i got, he bought it from new in 02 and passed his test 3months ago and gave it to me for getting through my test.

BikerGran - Ive been out this morning looking the bike over, no idea what i'd be looking at or for but found something that doesnt seem right........

On the right side of the bike just under the petrol tank there's a cable that loops round a sort of wheel, i believe this is to do with oil/petrol mix. Well this cable is sticking, the actually wire cable is a bit corroded (sort of white powdery) and when it's moving back and forth it's not pulling back through its black outer cover properly, sorta looks like a brake cable (terrible description i know, but im atleast having a look )

So, if this cable is sticking and the fuel mix isnt being done right, would this cause problem's?

I really am clueless with engine's, im a joiner and any time i have a problem with the car/van or bike i just get a mechanic to sort it, but i'm willing to try and learn new stuff. Could do with not spending any more money on this 125 as im hoping to get through my test soon and onto a 600

|Any help or advive is appreciated

Ah, so it's had it's fair share of use then. Fair play to the both of you.

I'm not familair with the little strokers these days, I'm trying to download a manual to have a look-see but I'm on Virgin and in the evenings they cap my speed - it's like being back on dial up

That cable operated wheel could be the oil pump or even some form of variable exhaust valve - either way if the cable's sticking something ain't doing what it oughta.

If the manual ever downloads I'll have a browse and stick some pics up for you.

Could even be the throttle cable needing lubing......

As BG says it could be the throttle cable your describing.

Cheers fastfitter, your help is appreciated.

Bikergran/fourtoes - Not sure about throttle cable, i'll descibe as best i can what i see -


I had a bit of free time this morning before starting work so lifted the petrol tank for a better look. This 'wheel' just rotates back and forth at random while the engine is running, not a great deal of movement in it at all really. As it turns clockwise it pulls the cable but on its return the cable isnt sliding back into its black outer sleeve properly. I used a bit of WD40 on it but I could probably do with getting some lubricant right through the sleeve but it's not easily accessible. (Atleast to a novice like me anyway) I was hoping to get finished work a lot earlier today to have a better look but it's dark now and also raining so i'll wait on some advice and possibly try something tomorrow.

It's about time i learned something other than knocking nails in!!

Cheers

Not this little doofah is it ......



... the bit that says 'valve' on it?

I'm guessing that's some sort of variable exhaust valve that opens or closes the exhaust port depending on how many revs (i.e. how much you're pulling the throttle) it's doing.

If that's stuck open it'll run sick at low revs, if it's stuck shut it won't rev out.

Again, I'm going on 'looks like' rather than hands on experience.

The download has stopped on 10%


Or is it this ....



from a thread on Bikechatforums here http://www.bikechatforums.com/viewtopic.php?p=2157511

Hi fastfitter, looking at that bottom pic i think the wheel im seeing is the one between the lines on number 2 with the cable running around it. I just went out and took a pic myself as seeing it from a different angle looks odd pic hope this helps identify it.

Cheers

That other thread suggests it's a servo motor - for what I don't know. I'll try and grab that manual in the morning when my speed is better (and the lads aren't hogging the bandwidth with their X boxes )

I can't get the manual to download, you may have more luck. It's here http://www.carlsalter.com/motorcycle-manuals.asp just scroll down the list.

Without that info I can't really say any more about whatever that bit is

Cant get anything of that site myself fastfitter, managed to download 1.25mb then it froze, tried other manuals and teh same happens with them all. Tried googling for a manual and get the same problems on other sites too, on some they want you to register to download but the sites looked a bit iffy. Spoke to my brother earlier though and he says he still has all the booklets and paperwork including a brand new spare key for the bike from when he first bought it, just has to hunt for it. He's due round in the morning to take my Hornet out so hopefully he'll have a manual with him

Im surprised i havent just gave in yet and dumped it on the garge forecourt, actually been enjoying a bit of tinkering. I even got round to fitting the crash bobbins to the Hornet today and managed a lap of the car park, in 1st gear!!!!

Well, I've managed to download the manual this morning, but it's not too clear what we're looking at. Kel, could you maybe take a couple of photos and put them up?

Hi Defiler, yeah no probs in taking pics but it'll have to be in the morning now. I think it's certainly that cable looping round the wheel between the lines numbered 2 on that picture fastfitter posted. That pic if im right is taken looking down on the bike so that wheel is the right hand side, just like the pic i took and posted is whats visible under the tank from the right side.

Cheers


Just managed to download that manual and I think it's either - RC valve motor pulley or valve timing pulley. these are the only 2 things i found that resemble what im looking at. The one for the oil pump is a single cable from what i can see that doesnt loop around.

Yeah - I'm expecting it to be the RC valve pulley. As Fastfitter says, that'll affect the running either at low of high revs. If you can't fix it properly you can bodge it, and fix it half-way open. Some monkey had done that to my brother's TZR250 PowerValves, so it ran okay through the rev-range. He stripped the engine and fixed it - ran much better after, and turned into a little screamer. I wouldn't recommend bodging it - much better to put a little more effort in and get it right.

Please enlighten my ignorance - what's an RC valve?

I know I was going on about how easy it is to maintain a 2-stroke but the one I know about is 1984 vintage!

Honda RC-Valve

The Honda Remote Control valve is designed and works in principle like the "AETC system." A small computer monitors engine RPM and opens and closes a 2 blade exhaust valve controlled by an electric servo. Honda equipped many two-stroke motorcycles such as the NSR125 and NSR250 models with RC - Valve powerplants.


I had to google and view a lot of pages for that info. Read up on a few bits and i think this could possibly be the cause of my problem. Read on one page that some one else had a problem with their NSR similar to what im experiencing (engine dying), meant to be due to 'sticky' cable. Havent been on it the past few days but hopefully tomorrow i'll get chance to have a better look and try lubricating this cable. This bike just needs to be running smoothly for a few more weeks so i can get my test done on it, (hopefully i have better luck than my last one)

Sounds like the Honda version of the power valve as seen on Yamaha LCs - A servo motor moves a blade valve across the exhaust port which, by dint of effectively lowering and raising the port lip, alters the exhaust timing improving the power throughout the rev range. If it's sticking then, as everyone else has said, the engine will be flat at some point.

Interesting. My RXS100 had nothing like that but I feel it would have difficicult to improve the performance as it was quite impressive anyway.

I managed to download that manual from CarlSalter this morning, took about 10 minutes - at 4am . I knew that my insomnia would come in useful sometime

Set your alarm clock Kel

No need for an alarm, i dont sleep much either

I managed to get the manual myself, so after looking through and finding the bits i was looking at (the sticky pulley/cable) I think i can do something to sort it. Just need to lubricate the inner cable to prevent it sticking inside the sleeve when it moves. Obviously I would still be clueless myself and would have been stuck with yet another garage bill if it werent for the replies here pointing me in the right direction, so thanks to all


My next project is changing the silencer and link pipe on the Hornet, i just have to do it, I like noisy bikes
The one im looking at is here