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davemdixon

Joined:

Jul 09

Posts: 1351

davemdixon says:

Varadero 125 Can it be de restricted

Can anybody tell me if the standard fuel injected Honda 125 Varadero can be de-restricted? Its a wonderfull little bike and because of the learner laws it only puts out 15 bhp. Riding 125s in the 60s 70s & 80s they were really quite quick. My old Honda 125 twin was a real flyer! Your comments I await. :mellow:

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  • Posted 5 years ago (09 February 2010 08:37)

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RoadieRoger

Joined:

Mar 09

Posts: 937

RoadieRoger says:

Varedero

That was the whole point of the Learner Laws, to restrict 125`s to 14.6 HP . I shouldn`t think it could be de-restricted as Honda of all people would not wish to fall foul of the Eurocrats . Your only consolation should be that according to the 125cc tests in the Spanish Magazines , it is the fastest . My X7 spoilt things in the 1980`s as it was too fast for Learners , hence the 125`s for Learners .If the boundaries are pushed again we will all be riding 50cc`s !

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davemdixon

Joined:

Jul 09

Posts: 1351

davemdixon says:

Thanks RoadieRodger

I will put it another way. Does anybody know of anybody who can supply info on tuning/modifying the standard engine (injected or carb) as I intend to modify one costs not being prohibitive :wink:

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MarcusMarsh

Joined:

Aug 09

Posts: 2721

MarcusMarsh says:

Derestriction

Hi,

As far as I understand, in the early days of restricted 125's the engines were actually restricted and/or re-tuned at the factory for the UK market and therefore easily restored to full power. (RD125 anyone?)  However, modern 125's are designed to put out 15 HP and as such ther is no 'restiction' to remove.  Tuning is another issue as this is the process of improving on the factory output rather than removing any artificial restriction fitted for a particular market.  To be honest with an engine of the type that you have I do not think that the trouble and cost of tuning would  yield any great increases in BHP and would certainly have an adverse effect on the levels of reliability that you now enjoy.  If you love the bike (and we all love our bikes don't we?) you may not want to hear this but the easy way to more BHP is to buy a bigger bike.

MM 

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davemdixon

Joined:

Jul 09

Posts: 1351

davemdixon says:

Trouble is

I have been riding since 1966 thats almost 44 years. I ride a Honda Transalp but I have only two years till retirement. My thoughts are to get something (whilst I am still earning) which wont be a handfull in the pushing about department. Something which I can ride all day (when you lot are at work) and cheap to run. I do enjoy a bit of acelleration when Im in the front of a traffic que. Do you see where Im coming from? My Honda 400/4 is to precious to use every day thats why I need a smaller bike. Also my son can ride it too. Regards Dave.:lol:

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philehidiot

Joined:

Feb 09

Posts: 4769

philehidiot says:

You can

Mod it with big bore kits as far as I'm aware but frankly the investment will be massive and on top of that as soon as you declare it to your insurance that it has been modified your premiums will shoot up. You can improve the power but then you'll possibly have to improve the brakes and it just opens a can of worms and can just sap money as you find more and more parts need replacing or wear stupidly fast with the extra power.


I looked at light, practical bikes and there were precious few - Ninja 250R, the Hyosung version (build quality issues?) and after that you struggle. I got a DR-Z400SM which is very light, but lacks any real carrying capacity - the Suzuki luggage rack only takes 3Kg which is enough for a few tools and other necessities. Top end speed - the Ninja and Hyosung will be better and top the ton but the DR-Z will beat them off the line as it's geared for low end torque. Mine tops out around 90mph but has about 5bhp knocked off due to 33bhp restriction.

For practicality I'd go with the Ninja as you get a good compromise with weather protection, fuel economy and it just being simple and therefore cheap to fix. If you want something ugly that you can tape stuff to and generally treat as an ugly workhorse, the DR-Z is great. You need some hand guards and / or bar muffs for winter but it's fuel economy is way below the Ninja at only 50mpg rather than 70mpg. You'll safely get 70 miles on a tank without hitting reserve on the DR-Z with 80 miles at a push which is a pain and leads to me filling up almost every bloody day.

Personally, I'd have kept my CBR125 if it would have been practical to upgrade it for even a small amount of extra power but it was more financially viable to get a bigger bike. It's just that 125s these days are designed to be low power and aren't restricted. Because many of them are smaller cylinder versions of 175/250s sold in the Asian market you can find big bore kits are easily available and often made by the manufacturer.

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Lukaz2205

Joined:

Jul 05

Posts: 26

Lukaz2205 says:

TUNING

You can tune it to some extent.

best thing to do if you want to spend the money is get a nice end can to boost the low-mid range. and get it jetted with a performance filter.

ive seen a 150cc bore kit about online but you cant get it in the UK.

gearing is another thing,

also the main restriction cant really be bypassed on the Varadero 125.

if owners look at the diameter of the piping at the headers from the front and the rear cylinders notice the rear is actually half the size.

after researching it, Honda have made the rear Exhaust ports smaller so to get a sufficient power gain you would need to bore the port out and replace the original piping on the headers with a bigger diameter pipe.

only problem with the latter is the gap between the motor and the frame is so small you would never do it unless you bring the pipework outside of the frame and make a heatshield for it.

i will attempt it at some stage but moneys not there at the minute.

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AlanR2

Joined:

Jul 11

Posts: 1

AlanR2 says:

Varadero 125 Can it be de restricted

14.6bhp is the theoretical maximum design limit - it is more likely that you are only getting about 12bhp - so even a 20% improvement won't take you over the limit!
You will notice that the exhaust headers are different diameters - a larger header on the rear cylinder will help.
Also, on Carburettor models, the rear carb has smaller jets and is setup weaker than the front cylinder.
Honda say that this is to stop the rear cylinder overheating - but it is a water-cooled motor!
There is a restrictor in the airbox lid - a small rubber bung that can easily be removed once you remove the fuel tank.  On Carb models, it is at the rear, on Injection models it is at the front.
The air filter element can also be modded by cutting-out the old element and grafting in a K&N filter (Part No. 33-2092).

Attached images:

  1. Inlet Pipe  
  2. KNFilter  
  3.  
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Lukaz2205

Joined:

Jul 05

Posts: 26

Lukaz2205 says:

Tuning

It Can be done, but you have to bear in mind your gonna have to chuck a lot of money at it....

i've been toying with it as i have a spare engine and being a motorcycle mechanic, can do alot of things myself.

Looking at major engine and fuelling tuning, based on the weight loss, and the power gains, i dont see why my bike shouldnt be able to produce 22.5VBHP.

although once im going to bore it out to from 48mm bore to a 52mm (anymore than this you will go into a water jacket! and just for sh*ts and giggles whack some Hi comps in,

The major "restrictions" are Exhaust headers, airbox and fuelling,

the exhaust headers have a core tube restriction in the front header and a manifold and pipe decrease on the rear (ever notice the different sizes between the 2 pipes?)

the front header has a O/D of 36mm with a wall thickness of about 1.5mm and the rear has a O/D of 25mm with same wall thickness.

the reason for this is basically honda being smart and using backpressure to basically restrict the motor by its self as the front cylinder with get slowed by the rear, because of the effort to push gases through a smaller diameter pipe. (blow through a calypso drink straw then through a normal one, same principle)

end result and thats including new camshafts,free flow filter,Jet kit, the bore out, high comps and maybe a thinner Head gasket and all the other add ons and there is a possibility of "achieving" 25-28BHP.

I'm only doing it as it makes it more different, yes you could try and slot a different engine in, but wheres the fun in it? ;)

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Hegegun

Joined:

Jul 12

Posts: 1

Hegegun says:

Varadero V2

Okey, can anybody tell me, what is main jets right size, when intake and exhaust is modifield. Original is 82 and 88, but motor run too lean...

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Lukaz2205

Joined:

Jul 05

Posts: 26

Lukaz2205 says:

Hegegun

depend entirely what you've done to the intake and exhaust? the header pipes are restricted anyway so changing it wont make a great difference as most systems copy the honda pipework witht he restrictions to stop being sued...  and they have a tubular core baffle restrictor in the front header underneath the motor, if you have taken these out it'll run leaner anyway, the rear carb has a smaller jet to the front, try wemoto and go up a size from standard (number written on the jet itself) on the front and put the standard one front into the rear carb.

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