Sarah's new baby

[Miztaziggy]

So I took tony's advice and bought the bike I had seen on ebay, in the hope that at worst, I could strip the 180 kit, fit the original 125 cylinder (came with it) and get a bit of money back...the bike also came fitted with a full Yoshimura stainless exhaust and the standard one too, with a viper end can. At worst, that stainless system will sell for a couple hundred, so not done bad I think. With it on, the bike actually sounds quite nice on tick over.

I have just ridden it all the way home from near Whitby to Huddersfield, about 100 miles. To be perfectly honest, it was actually quite fun. It is so unbelievably light compared to the VTR, I almost came off it at the first corner as I threw it into the corner and it turned much quicker and much sharper than I expected. The brakes are really good on it, the back brake is actually much more powerful than the back brake on my VTR. The tyres are really good too, they get so hot and sticky. Much more so than mine

The guy who we bought it from was sound enough and was honest with us when he said the 180 kit he fitted made bugger all difference to the power...now im guessing that with a standard carb, it wont be getting enough fuel to make a difference? Can anyone confirm?

If that is the case, and bearing in mind all I know about a carb is literally that it mixes air and fuel (never even seen inside one I dont think), would replacing it add more power, or can I modify the existing one? And is it something anyone can do or am I best taking it to a shop?

Well here it is:

Oh and one last thing, I am quite disappointed by the fact that I passed loads of bikes on the way home, and nodded as usual but not one nodded back. I dont understand why so many bikers refuse to nod to what they think is a learner. We all (or most of us) started out on one....




And Sarah (who hasnt done her CBT yet) having a quick go round my office car park to try and learn how to set off and stop on a geared bike

[Dthomp87]

looks clean. love the blue.

To adjust air fuel ratio, you will need to change the jets in the carb. You do not need a new carb to change the amount of fuel mixed with the air. engines are jetted differently depending on what air filter and what exhaust system it has on it. It is something you could do yourself as you can buy different sized jets online quite easily. although picking the right one might be difficult. they do sell jet kits so you can try out different sizes but, it is a pain in the ass to change them, you have to take the carb apart to do so. there are people online you may be able to find that have jetted a similar setup would be your best bet, but if you got the money and you want it done right, take it to shop that is skilled in jetting carbs, when a bike is jetted correctly it makes all the difference. so many people fool with the jets and throw everything way off dont know what they are doing. its all science really.

[benny hedges]

bet she loves it matey - it looks great

good luck with the cbt & test(s)

[Miztaziggy]

Yep, she loves it Benny, her test wont be until next April time, but hopefully she will have loads of experience by then.

I think she wants to bring it down to the next Derbyshire meet. I said that we can set off early on the Friday and go the back roads down there so she can have some fun, ill just sit behind her all the way. Then on the Saturday she can come on the back of me for the ride out so she isnt holding everyone up, then ride home Sunday via the back roads again so she can get some more miles under her belt

looks clean. love the blue.

To adjust air fuel ratio, you will need to change the jets in the carb. You do not need a new carb to change the amount of fuel mixed with the air. engines are jetted differently depending on what air filter and what exhaust system it has on it. It is something you could do yourself as you can buy different sized jets online quite easily. although picking the right one might be difficult. they do sell jet kits so you can try out different sizes but, it is a pain in the ass to change them, you have to take the carb apart to do so. there are people online you may be able to find that have jetted a similar setup would be your best bet, but if you got the money and you want it done right, take it to shop that is skilled in jetting carbs, when a bike is jetted correctly it makes all the difference. so many people fool with the jets and throw everything way off dont know what they are doing. its all science really.

Thanks for that - very useful information

The air filter has been changed for a K&N filter and the cylinder is a big bore thing, is there anything else other than the carb set up that could be hindering the power output?

On that advice, I think I will make some calls and see what it will cost to get the jets changed properly. If it is too much, ill just strip off the 180 kit, refit the 125 and sell the 180 kit and full stainless exhaust to get a good chunk of the money back.

[AMCQ46]

looks great, and she looks quite confident in the car park .

PB did a big bore conversion on a Yam 125 a few months back, and I am sure there was some issues in getting the fueling right, so I will have a look through the collection and see if I can find the correct issue.
Will scan it and e-mail to you if you want

[Miztaziggy]

looks great, and she looks quite confident in the car park .

PB did a big bore conversion on a Yam 125 a few months back, and I am sure there was some issues in getting the fueling right, so I will have a look through the collection and see if I can find the correct issue.
Will scan it and e-mail to you if you want

Yeah nice one mate, thank you

[tony.mon]

Looking very nice, jealous, though, as I'm looking for something similar for my daughter in August, once she's 17.

Just because it's a 125 doesn't mean it can't go on a dyno, and the carb can be set up properly.

I don't quite agree that it's just jet changes; it might be necessary to gain the maximum power increase to go up 2mm on throat size.
Haynes will tell you the standard size, and then have a dig round a big breaker to find something of the correct throat size that could be persuaded to fit.

The jets on a 2mm diameter bigger carb should be closer to the sizes needed, but will still need setting up.

But you might find it won't tick over smoothly, or rev out properly until it's been set up on a dyno, though.

Lastly it'll need a less restrictive end can to utilise the extra airflow from the big bore and the K+N.

What did you pay for it?

[Miztaziggy]

Paid £1400 for it, which I dont think it is that bad as it only has 8800 miles and almost mint condition. There are 2 little marks on the fairing and a stone chip, no evidence of ever been on its side etc etc it even has some really nice aftermarket indicators (which I might take off and use on my VTR).

It already has a better exhaust on it, it has a full stainless Yoshimura one and it looks quite nice. It even sounds quite nice. It came with the standard pipe with a Micron end can too, which does look smaller at the cylinder end.

Are you going for the CBR for your daughter? Sarah will be selling hers around then (end Aug / start Sep) if you are still looking (and she hasnt crashed it). If you end up getting one sooner, make sure you go see them rather than blind bidding/buying from ebay. We went to see a few, all saying excellent condition and mint condition....well, they weren't. Most had clear evidence of being crashed. Not just a scratch, but badly repaired clutch covers, welded brake pedals, one with a taped up light and speedo that had been broken etc etc

Hmm, I wondered if it might need a bigger carb. I assume when you say a bigger throat, that will be what everyone refers to as a 38mm carb, or a 42mm carb or whatever.

[tony.mon]

Yes, re carb throat, but check sizes as you're more likely looking at a 24 or 26mm diameter.....

Yes, I'll take that off you and give you your money back.

Have you got the original parts?
Piston/rings/barrel etc?

[Miztaziggy]

Yep, I have all the original parts, other than the standard indicators and standard end can.

There is the standard air filter, and standard downpipe, plus there is the standard barrel, with a piston head with 3 rings already on it. There are also 2 black plates, they look a bit like gaskets but are made from like thin sheet metal, dont know what these are.

[AMCQ46]

Found the article in PB, but the yam has fuel injection, so there was a fuelling box with the kit they used, but they needed some dyno time to get it to work.
Will still scan it tomorrow if you want. PM me your e mail and I will send it you.