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XVS 125 de-restrict


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Hay all

I own a xvs 125 Dragstar 2004 and will be doing my test next month.

I dont really wish to change the bike as its mainly used for back and forth to work but im wondering

if it is restricted and it there an easy way to derestrict????

will an exhaust change do the trick or is there any washers in place that can be removed??

im not sure about the legal requirements for this but im assuming its okay once I have passed my test

any help would be great people

Cheers

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Hay all

I own a xvs 125 Dragstar 2004 and will be doing my test next month.

I dont really wish to change the bike as its mainly used for back and forth to work but im wondering

if it is restricted and it there an easy way to derestrict????

will an exhaust change do the trick or is there any washers in place that can be removed??

im not sure about the legal requirements for this but im assuming its okay once I have passed my test

any help would be great people

Cheers

there is tonnes of 18 year olds and riders who are ment to be on 33bhp

who are riding their bikes on full power

the cops dont no

there will be a restrictor in the carb i would imagine

take out bafflers might make it move abit quicker and sound better obv

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Hay all

I own a xvs 125 Dragstar 2004 and will be doing my test next month.

I dont really wish to change the bike as its mainly used for back and forth to work but im wondering

if it is restricted and it there an easy way to derestrict????

will an exhaust change do the trick or is there any washers in place that can be removed??

im not sure about the legal requirements for this but im assuming its okay once I have passed my test

any help would be great people

Cheers

My son has the earlier XV125 and I have had a good look round and it seems that this engine is built to be "gutless". As the baffles are not removable I have drilled 8x8mm holes around the plate in the back end of the exhaust. It didn't make much difference but at least it now sounds like a V twin.

There does not seem to be any restrictor in the carb but there is what looks like a restrictor in the air filter which when removed caused the bike to die when the throttle was opened due to too lean a mixture. As I didn't have any larger jets to try I don't know what size would be needed to run without this but it may be a good place to start. Raising the needle one notch may also help.

A change of gearing is another easy change to make. If you increase the rear sprocket by 2-3 teeth the acceleration will be better but the top end will suffer and conversly dropping a couple of teeth will increase top end whilst decreasing acceleration.

If you do manage to get more power out of this lovely little bike please let me know. I will be trying it myself soon as my son has passed his test and is nagging for more power.

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  • 1 month later...

I had this very conversation with another XVS125 owner on YouTube, I'll copy/paste the messages he sent:

if you DO want more power from the Dragstar, i've found that with a ever-so-slightly modified 35mm purple cone-shaped air filter that WAS meant to go on a scooter, WITHOUT jetting, has upped the power a bit in the low-end already, with the 48mm and the Jetting it'll be getting soon, i hope to finally be able to consistently do 60mph! haha!

I asked which filter was the best to use for the XVS125;

Well, there ARE no specific replacement airfilters for the XVS125, because its just, not a bike that people tune up, HOWEVER, that doesnt mean its un-tuneable!

On eBay, you'll want to simply type in "48mm air filter" and select whichever one you like best, and the reason it took a 35mm inside the pipe behind the shield-shaped air box is because we wrapped it up to 52mm with insulation tape, so its a dodgy fit, and very wobbly, but with a 48mm, all you need to do is shave a couple mm's off the outside of the fitment rubber and it'll fit in there superbly, then just jimmy-clip it in place and have the bike Jetted!

Bear in mind that with a 48mm direct flow airfilter, your going to NEED the bike jetting, because its breathing so much more with that filter that the fuel-air mix goes up the swanny, so, jet it with a 48mm sports air filter, and your gonna definitely see an increase in power! :D

Thats what im currently doing, got the 48mm filter in the post the other week, im currently shaving down the neck-rubber on it till it fits inside the pipe behind where the air-filter-shield-thing was, then i'll be taking the air-filter, and the bike, to my local workshop, and putting the filter on there, can't ride it without having it jetted up with the filter i'm afraid!

Get it jetted, and dyno'd, and i'll let you know what my power goes up to, STANDARD the bike should put out 12bhp, but im hoping for more with this.

If anyone could break this down and clarify every step, that would be superb!

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  • 2 months later...

I had this very conversation with another XVS125 owner on YouTube, I'll copy/paste the messages he sent:

I asked which filter was the best to use for the XVS125;

If anyone could break this down and clarify every step, that would be superb!

Hi Brainstorm, did you eventually follow this up & fit a filter ? If so then i'd be interested in how it went.

I've just bought one on eBay for £5.50 (eBay number 150291281345) and it looks as though it might fit behind the chrome air-filter cover. There's a 2cm recess into the actual boot, and a further 4cm of room between the inside of the chrome cover and the start of the inner boot, so 6cm available for the filter to sit within.

There's no dimensions on the eBay item so i'm taking a gamble on this to be honest, but it seems like a low dollar risk for what could be a useful increase in HP.

I've no idea about re-jetting but am prepared to give it a go myself when i find out how it's done.

Cheers,

Mark.

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  • 3 weeks later...

hello i have a sachs roadter which uses the v twin engine from the xvs, i have added a larger back sprocket and yes you do see a small increase in acceleration while losing a bit of top end, i certainly think that that adjusting the fuel air mixture would offer a small increase in performance although i don't know wether changeing the filter will work for me as the airbox is located under the tank as opposed to the location on the xvs but i will certainly take the tank off to see if this works.

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  • 1 month later...

hiya chap, it's not really worth it, but if you have two single open exhausts with baffles fitted and do away with the old system, costing about 300 quid, it helps a hell of a lot, and it stops rot in the collector box too. aswell, fitting a performance air filter and changing the sprokets, but you will also have to tune it to stop it cutting out or as someone else said, it will just cut out, hope this helps

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