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Ogri

xvs 125 you can get a bit more poke

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Cheers for the replies.

Ordered a sissy bar and rack on Tuesday I think it just finishes the bike off. I love the look of the bike and the way it drives, very comfortable, its the hills that do my heed in lol but for getting around I am enjoying riding the bike. I am am not so keen on the DTR more of a off road bike for me. One of the things I do like about the Dragstar is sounds like a big bike.

Goff not about speed of me its about gettting up hills nicely and there is tons of the mothers were I live, If I can cruise at 70 I would be happy. Are you serious about a hypercharger being fitted to dragstar????

I think its time to think about driving test to get a bigger cc really got the bug for the bikes now considering I was an old die hard scooterist.

SORRY m8 highjacking thread.

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the answer to your question badbrad is twofold with the bike we both have its horses for courses it was never designed for fast acceleration or a top speed like a lot of 125s,its a cruiser comfortable to ride and good looks with the harley fat boy look,yamaha continued with the 650 and 1100 but dropped the 125 although it sold it did not sell in the numbers to enable them to continue to produce the main reason customers gave was slow acceleration and a poor top speed i was told this at a bike show by a yamaha executive so if they couldn,t get any improvement with all there expertise i dont think we will have much luck but if your happy with the looks and comfort enjoy it as its my day to day bike i love it for those reasons,did you get yourself a sissybar? i got one of e bay £107 +£10 delivery highway hawk it said on the box for 1100 dragstar but it does fit the 125 and is good quality it is 7 day delivery but worth the wait, and as oldgit said if you want a bit more speed there are plenty of other 125,s out there capable of a bit more, have fun mate

Cool I actually got your bloods pumpin and your dandars up. Don't be stressed people I'm not here to upset (too much). I've been watching this site for a while before I even signed up and realised that there plenty of owners who post and get no replies at all. I also noticed that there are plenty of small bike owners who want to improve the performance of their machines for one reason or another. By pissin people off (just a little) from time to time I have often found that those in the know actually try to prove it by parting with their knowlage. I find it hard to believe that the vast knowlage posseced by the entire Yamaha Owners Club membership dosn't even know how to de restrict a 125cc machine. Yes we know the Dragstar was made to luck pretty and that it's not designed for the race track but come on 60 MPH top wack? At least if there was more power you would be able to fit a screen with out the wind resistance killing another 10 mph. Oldtimer I asume you have been guilty of being a "ton up pirate" at least once in your life? hey that was dangerous! infact it was a bit more dangerous than removing a valve that restricts air flow to the tank causing deceloration usually when you need it the most and if the said plastic thingie isn't an overflow stop valve what do you call it? I also know 4 people who have removed the "thingie" and have noticed an increase in power. I therefore believe that it should now be refared to as a restriction valve, unless any one else knows better. With all of your years of experience do you know how to increase the power of a 125 dragstar? if so loosen the tongue, if not bite it. I'm only sharing something which I've managed to glean from some where other than this site. Does that make me a baddie? It's bad form to take the piss out of some one who is trying to help.I'm sure that you can also remember a time when not every one was arsed about safety. I know I can and I've only been riding on and off for 30 years myself. I have had other bikes in the past and used to enjoy riding my old BSA A10 on international rallies back in the days when it didn't seem to matter weather you'd passed your test or not. Nobody cared! Fool hardy yes, dangerous? not really. And yes I've built quite a few bikes myself in the past, but still don't confess to know all the answers. Niether should you. The Guys at my local motorcycle repair shops dont know how to get more from these draggies and were made up to find thyat I had at least one of the answers and they didn't know the true name for the thingie either. Finally not all bikers are interested in how safe you can make a bike. There are different strokes for different folks. If you really don't want to be in danger you could always just drive your car, but hey where's the thrill in that? My brother in law is the librarian for the BSA owners club, he enjoys restoring old bikes, rallies, touring and being a riding safety insructor. That's his gig. I'm just an old fashioned, old school ex angel who is finally making an effort to grow up just a little, and take a test or two to make it legal. But only because the law would take me off the road if I didn't. That's my gig and who has the right to tell me I'm wrong?

No offence to ment Goff either. But agreeing with every one elses smarty pantses dosen't really add to the thread. And could you make up your mind concerning road safety, one second it's not agreeing with wearing no helmet etc, the next breath you can only get 110mph out of your bike on a public road I assume? (smack your self on the wrist you naughty girl)If you have some input as to how to increase the power output to a 125 dragstar without drasticly altering or modifying then out with it as thats where the thread originated.

Hope I havn't pissed you all off too much as you never know we might even get an answer to the original idea of the thread some day.

Love you all OGRi :icon_twisted:

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I'm just an old fashioned, old school ex angel who is finally making an effort to grow up just a little, and take a test or two to make it legal.

An ex angel with no licence and riding a 125....... which chapter were you with then?

No offence to ment Goff either. But agreeing with every one elses smarty pantses dosen't really add to the thread. And could you make up your mind concerning road safety, one second it's not agreeing with wearing no helmet etc, the next breath you can only get 110mph out of your bike on a public road I assume? (smack your self on the wrist you naughty girl)If you have some input as to how to increase the power output to a 125 dragstar without drasticly altering or modifying then out with it as thats where the thread originated.

Did i say i got 110 out of my bike on a public road? I think i actually said was "im lucky if mine tops 110" - at no time did i say i had ridden it at that speed - assume nothing.

And my mind is quite clear on road safety thanks very much. Coming on here to wind folk up for no reason other than you think it will get a reply and that its funny is NOT the way we do things around here. Many threads dont get answered because folk dont know the answer or miss the thread completely.

Your posts are full of smart comments and wise cracks, and serve no other purpose other than to wind folk up - and you seem to know it all so why should we even bother??

We had one like you not so long back - he didnt last too long.

You are more than welcome on this forum - but your comments made to deliberately wind people up are not.

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well ogri it would take more than your inane comments to get my blood pumping or my dander up ,if you had read and understood my reply to your post you would no doubt have noticed that i was just letting you know what the plastic thing was and its function i was not taking the piss out of you you seem to be doing a good enough job without my help as for your local motor cycle repair shop if they dont know what a non return valve is and its function they are not mechanics but that new breed of fitters who just replace parts until they get it right,from your post i mistakenly thought you were a lot younger and just didn,t know much about bikes not that you had been riding 30 years and not learnt anything i will not bother replying to any further posts of yours as you still seem to have that plastic thingie between your ears making it impossible to understand anything, and yes i was a ton up kid and enjoyed every minute of it speed is good. It is way better to be shot out of a cannon, than squeezed out of a tube. That is why God made motorcyles.9 and yamaha of course)

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..come on boys & girls, stay focussed on the issue (despite the chat being fun to read), the issue being getting more MPH out of an XVS 125 without butchering it (& therefore buggering it's resale value).

I think a bit of Sprocketary work might be the order of the day, although too much would of course increase the effort needed to get up to speed as quick as a standard set-up. However, if you're prepared (as I am) to sacrife a little 0-60 if favour of a 65mph cruising speed (instead of 55mph now) then non-surgery seems appropriate.

Trouple is, i've not found anything for sale other than standard front & rear (although i presume I could have them made??).

So come on, what are my options ?

Mark.

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..come on boys & girls, stay focussed on the issue (despite the chat being fun to read), the issue being getting more MPH out of an XVS 125 without butchering it (& therefore buggering it's resale value).

I think a bit of Sprocketary work might be the order of the day, although too much would of course increase the effort needed to get up to speed as quick as a standard set-up. However, if you're prepared (as I am) to sacrife a little 0-60 if favour of a 65mph cruising speed (instead of 55mph now) then non-surgery seems appropriate.

Trouple is, i've not found anything for sale other than standard front & rear (although i presume I could have them made??).

So come on, what are my options ?

Mark.

Hi Mark,

Glad to hear you've enjoyed the story so far. I was thinking about what you said and it appears to me that if "I" was to leave the air restriction valve off (ie said plastic thingie) and drop a couple of teeth on the rear sprocket "I" might loose some ,but possibly not all of the acceleration gained whilst at the same time increasing top end.

Also there's an update on the suspected breather valve / restrictor valve. Two local bike mechs' who have 50 years combined experiance recon that the valve is to restrict air flow into the tank and not to stop the leakage of fuel as the valve is actualy set to flow in the opposite direction. IE the valve closes when too much air goes in and would be open if fuel was to leak out.

What do you recon? OGRi

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Also there's an update on the suspected breather valve / restrictor valve

I see you say there is an update on the above value what does this update do?

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Markyboy, check out wemoto.com - they've got a line on front sprockets with less, standard or more teeth as required. If I've got my maths right you want a front sprocket with less teeth (?) to get a higher top end.

I doubt very much if that will actually happen though. I don't know what everyone else thinks but the problem is not my bike maxing out at the top end it just doesn't have the guts to get there in the first place :(

Goff, oldtimer et al. I had a bit of a think about what you said and hacksawed the top off my plastic thingy and it does look like the plastic ball inside is designed to stop air going into the tank. If the bike were to fall over wouldn't the ball just sort of flop about in the middle of the flow control unit? Having said that, I'm a bit worried about all this flaming balls of fire thing, I've got kids to worry about, so I've put a reclaimed unit back in place.

While I've got your collective attention; I've been thinking about highway hawk pipes for mine - do they give the bike anything other than a better look and sound?

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Markyboy, check out wemoto.com - they've got a line on front sprockets with less, standard or more teeth as required. If I've got my maths right you want a front sprocket with less teeth (?) to get a higher top end.

No its the other way round, larger front sprocket = Faster top end, (Except the engine hasnt got the power to pull it :angry: )

Smaller front sprocket = Faster acceleration and slower top end

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yes you are right the ball bearing flows along the valve and the function is the control of air,if you look it at all logically the pipe is called a breather pipe, as a combustion engine you need the right amount of air and fuel for the engine to run ,to much of one and not enough of one or the other to the engine then you starve the engine or strangle it.

fuel or any liquid will find its own level the breather pipe is not there for fuel to go down, but because of a syphon effect that is what can happen when air is displaced, and that is why when racing a bike scruttineers will check that the breather pipe has not been altered yes it can give a advantage but there are disadvantages.

at the end of the day what ever anyone says they are your bikes and you have a free choice what you do with them, as a fellow biker i am just giving an opinion if you google breather pipe or functions you will see plenty of information from a lot of different sources.

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Markyboy, check out wemoto.com - they've got a line on front sprockets with less, standard or more teeth as required. If I've got my maths right you want a front sprocket with less teeth (?) to get a higher top end.

I doubt very much if that will actually happen though. I don't know what everyone else thinks but the problem is not my bike maxing out at the top end it just doesn't have the guts to get there in the first place :(

Goff, oldtimer et al. I had a bit of a think about what you said and hacksawed the top off my plastic thingy and it does look like the plastic ball inside is designed to stop air going into the tank. If the bike were to fall over wouldn't the ball just sort of flop about in the middle of the flow control unit? Having said that, I'm a bit worried about all this flaming balls of fire thing, I've got kids to worry about, so I've put a reclaimed unit back in place.

While I've got your collective attention; I've been thinking about highway hawk pipes for mine - do they give the bike anything other than a better look and sound?

..cheers Matt, i'll give it a go & let you know. Not too fussed about time to get there, just want to lower RPM at full crank in order to delay the on-set of catastopfic detonation of the expensive shiny bit.

Cheers,

Mark.

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Markyboy, check out wemoto.com - they've got a line on front sprockets with less, standard or more teeth as required. If I've got my maths right you want a front sprocket with less teeth (?) to get a higher top end.

I doubt very much if that will actually happen though. I don't know what everyone else thinks but the problem is not my bike maxing out at the top end it just doesn't have the guts to get there in the first place :(

Goff, oldtimer et al. I had a bit of a think about what you said and hacksawed the top off my plastic thingy and it does look like the plastic ball inside is designed to stop air going into the tank. If the bike were to fall over wouldn't the ball just sort of flop about in the middle of the flow control unit? Having said that, I'm a bit worried about all this flaming balls of fire thing, I've got kids to worry about, so I've put a reclaimed unit back in place.

While I've got your collective attention; I've been thinking about highway hawk pipes for mine - do they give the bike anything other than a better look and sound?

..cheers Matt, i'll give it a go & let you know. Not too fussed about time to get there, just want to lower RPM at full crank in order to delay the on-set of catastopfic detonation of the expensive shiny bit.

Cheers,

Mark.

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..cheers Matt, i'll give it a go & let you know. Not too fussed about time to get there, just want to lower RPM at full crank in order to delay the on-set of catastopfic detonation of the expensive shiny bit.

Cheers,

Mark.

..nice one Matt, bought a '1 tooth bigger' & '2 teeth bigger' front sprockets for £15 inc. postage !

All I need now is a tent & a billy-stove for the over-night stop caused by the extended time to reach cruising speed !

F@ck it, i don't care. I just hate thrashing a lovely bike.

Thanks,

Mark.

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All I need now is a tent & a billy-stove for the over-night stop caused by the extended time to reach cruising speed !

I thought this was standard kit on this bike already! :lol:

I'm glad I could be of help - I've got a load of parts on the way from Wemoto too, I reckon the new spark plugs are going to go a LOOONG way to making my bike faster. I've just measured the old ones at 1.4mm and 1.6mm gaps! Aaargh!

That explains why I thought you were all lying about the '70mph is possible' thing :blink:

Seriously though Mark, let us all know if it makes a difference - I'll keep an eye on this post for your story :P

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No its the other way round, larger front sprocket = Faster top end, (Except the engine hasnt got the power to pull it :angry: )

Smaller front sprocket = Faster acceleration and slower top end

..ordered a 1-tooth larger & a 2-teeth larger front sprockets from Wemoto for £15 (for both plus postage) so at that price i'm happy to experiment.

Found a great stretch of downhill dual carriage way near the A6 at Barton (near Luton) which has a 2 mile down hill (and as a consequence a 2 mile back up again) so will bench-mark the standard vs the 1-tooth bigger and the 2-tooth bigger sprockets for both Top Speed and of couse time to get there.

I suspect the uphill return will be a slower ascent, there being more drag due to the larger sprocket, but if it's tollerable then the gain on the down-hill & flat section may be worth-while.

Over-boring & bigger pistons would be an option but as i'll be selling soon then won't be taking such drastic measures.

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I thought this was standard kit on this bike already! :lol:

I'm glad I could be of help - I've got a load of parts on the way from Wemoto too, I reckon the new spark plugs are going to go a LOOONG way to making my bike faster. I've just measured the old ones at 1.4mm and 1.6mm gaps! Aaargh!

That explains why I thought you were all lying about the '70mph is possible' thing :blink:

Seriously though Mark, let us all know if it makes a difference - I'll keep an eye on this post for your story :P

...the spark-plug thing is interesting, what exactly did you buy from Wemoto and how did you know what to order ? was it based on a recommendation, or by a response on this site to the question of what to buy ?

Cheers,

Mark.

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Also there's an update on the suspected breather valve / restrictor valve

I see you say there is an update on the above value what does this update do?

..didn't do much to be honest, i think it was all hype. I'm still capped at 70mph down-hill, which was what I was limited to with the orignal valve fitted. I wouldn't bother.

Check out my updates elsewhere on the bigger front sprockets (1-tooth bigger & 2-teeth bigger), both should arrive early next week so will provide updates on the effect they have on possible higher MPH and also any increased drag on the engine by consequence of the change.

Cheers,

Mark.

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I thought this was standard kit on this bike already! :lol:

I'm glad I could be of help - I've got a load of parts on the way from Wemoto too, I reckon the new spark plugs are going to go a LOOONG way to making my bike faster. I've just measured the old ones at 1.4mm and 1.6mm gaps! Aaargh!

That explains why I thought you were all lying about the '70mph is possible' thing :blink:

Seriously though Mark, let us all know if it makes a difference - I'll keep an eye on this post for your story :P

..just took another run with the 1-tooth bigger sprocket on and am pleased to say the reduction in power is negligible, but the improvement in MPH is just what i was looking for.

Before i was changing up into top at 55mph, and screaming at 70. Now I change up to 4th at 55, and into top at 65which means by the time i'm up to 70 it's inthe mid-rev range. I checked again on a long uphill and I still gain, as before on the same hill i was capped at 45/50, whereas now i'm at 55 and creeping up (depending on incline).

So, having discounted the petrol tank breather valve mod as ineffective i'd say I now need to look at the 48mm air filter & re-jet mod for more horses to overcome the slight power loss attributable to the bigger sprocket, and if I find more horses I can then try the 2-teeth bigger sprocket... scary !!

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So, having discounted the petrol tank breather valve mod as ineffective i'd say I now need to look at the 48mm air filter & re-jet mod for more horses to overcome the slight power loss attributable to the bigger sprocket, and if I find more horses I can then try the 2-teeth bigger sprocket... scary !!

Yep, more likely to find "more horses" (or part of a horse) this way :thumb: If you put on a less restrictive filter on, dont go mad with the re jet (Not too big a jump) though, then plug chop to see if its about right!

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Yep, more likely to find "more horses" (or part of a horse) this way :thumb: If you put on a less restrictive filter on, dont go mad with the re jet (Not too big a jump) though, then plug chop to see if its about right!

..ok, here's the deal. An eBay EMGO 48mm air filter (K&N copy) will cost about £8, although on 1st inspection it doesn't look like it'll fit in the airbox.

Here's how it will:

remove the rubber boot from the neck of the EMGO filter, just leaving the chrome filter itself.

This will then drop into the airbox recess with about a 1mm clearance (rattly) You'll notice then that the Airbox chrome shield cover will not now fit (the airfilter is about 15mm too long) so a few changes are needed:

1). As the chrome filter is a loose fit into the airbox recess it needs about 4/5 wraps of electricians tape around the circumference of the chrome housing (play about with the amount of layers until it pushes in nice & tight).

2). remove the decorative hex bolt fron the centre of the chrome cover (doesn't do anything other than look nice), which saves about 6mm.

3). Take hold of the filter and snip the solid tin support post that runs along the length of the filter and helps the filter keep it's shape. Bend the end of the post over (don't rip it out as you'll tear the mesh) so there's a 1cm gap between the post and the filter's chrome end cap.

4). Holding both ends of the filter firmly, twist the filter to 'squish' the shape, which will by default reduce it's length. This should mean that if you compress the filter between the palms of your hands it will shrink in length without any major damage to the structure of the filter mesh (the mesh folds simply curve to make the new shape).

5). Having fitted the filter tightly into the recess you can now fit the airfilter shield-shaped cover by securing it with the 5 hex screws. This will 'squish' the filter until the housing is secured correctly, ensuring the filter is pushed home into the housing recess making a good seal.

6). Now you need to re-jet the bike to ensure it doesn't run too lean.

I spoke to our local shop and they said they'd re-jet it for about an hours labour plus the cost of the jet, which seemed reasonable to me.

I fitted the filter this morning and will run it over for re-jetting tomorrow so will let you know how it goes.

Total cost of this mod ?

£50 re-jetting labour

Cost of jet (?)

£8 filter

probably about £65 total.

Mark.

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