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im thinking about upgrading engine size in my dt125

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mivster
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PostPosted: 12:25 - 27 Sep 2011    Post subject: im thinking about upgrading engine size in my dt125 Reply with quote

im thinking about upgrading engine size in my dt125
i was thinking about a 200-250 cc
is this possible how hard is it to do and will will i need to change anything else. also any ideas which engine to use
i want to stay with a 2 stroke engine
its not definate but if its not to hard or pricey might have a look at doing it over winter
thanks
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G
The Voice of Reason



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PostPosted: 12:52 - 27 Sep 2011    Post subject: Re: im thinking about upgrading engine size in my dt125 Reply with quote

The easiest, cheapest and most sensible way would be to sell your bike and buy a 200-250cc one, I'm afraid.

You would probably have to make up new engine mountings, change various electrics, change the carb, get it setup to use the wrong airbox or change that and a few other bits.
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chris-red
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PostPosted: 12:53 - 27 Sep 2011    Post subject: Reply with quote

Buy a bigger bike easier, probably cheaper and you end up with a better machine.
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binge
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PostPosted: 13:17 - 27 Sep 2011    Post subject: Reply with quote

Mate of mine has just fitted all YZ250 engine and running gear into a DT125. Suspension and all! Thumbs Up

Proper immense bike, but useless for a road bike. Rebuilds are a regular things etc.


It can be done, but if you need to ask people how to do it, then I dont think it's something you'll be capable of doing.




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G
The Voice of Reason



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PostPosted: 13:34 - 27 Sep 2011    Post subject: Reply with quote

binge wrote:
Mate of mine has just fitted all YZ250 engine and running gear into a DT125. Suspension and all! Thumbs Up

Wouldn't it have just been easier and better to road register the YZ frame Confused.
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Teflon-Mike
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PostPosted: 14:19 - 27 Sep 2011    Post subject: Reply with quote

G wrote:
binge wrote:
Mate of mine has just fitted all YZ250 engine and running gear into a DT125. Suspension and all! Thumbs Up

Wouldn't it have just been easier and better to road register the YZ frame Confused.


I would imagine imesurably so; except that dating letter from Mitsui would declare frame & engine numbers for the bike as 250...... Which would of course not be Learner Illegal.....

OP; As others DT is a good little 'Street-Scrambler', a duel purpose on-off road bike. As such its a Compromise machine, a jack of all trades and master of none. Pretty good compromise, but still a compromise.

Modding it; will normally not make it any more valuable; and for the effort, not 'as' good as something that out the box does what you want.

Plenty of 200-250 is two stroke dirt bikes around; and choice from full on MX machine, through competition Enduro, Road Enduro to Road & Trail, to pure comp trials; an awful lot with price tags less than you'd get selling on your DT.

Which begs the question; WHY fuck about with a decent little DT, to make it not as good as any of the alternatives, wasting money; time and effort for the 'reward'.... there is but one obviouse answer and that is that at the moment, its wearing an L-Plate! THAT can easily be remidied with a lot less hassle with £121.50's worth of tests; or if you are want to ride illegally on a bike you dont have licence or insurance for; fuck off the poretence and swap the DT for 250 and ride THAT no licence or insurance, you would probably actually be brealing fewer laws for the greater gain!
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ClockworkJesu...
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PostPosted: 14:45 - 27 Sep 2011    Post subject: Reply with quote

Teflon-Mike wrote:
fuck off the poretence and swap the DT for 250 and ride THAT no licence or insurance, you would probably actually be brealing fewer laws for the greater gain!


I second this notion.
At least on a 250, you're only riding a bike you're not licensed to ride.

Now, on a 125 with a 250 engine, you're riding an illegally modified, unregistered motorcycle, with no insurance, that you have no license to ride.

Just go the whole hog. It's actually more legal. Mr. Green
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G
The Voice of Reason



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PostPosted: 14:50 - 27 Sep 2011    Post subject: Reply with quote

But for all that hassle and money, they could have no doubt passed their test, presuming that's the case (which I'm not so sure about in this case.)

You are still, I'm sure, a lot less likely to get caught riding an upgraded 125 than a bike originally intended to be a 250.
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Teflon-Mike
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PostPosted: 15:08 - 27 Sep 2011    Post subject: Reply with quote

G wrote:
You are still, I'm sure, a lot less likely to get caught riding an upgraded 125 than a bike originally intended to be a 250.


Depends, doesn't it?

Scenario's:

a) DT125; L-Plate on the back, probably under sized, one on the front wrapped around fork leg, 'questionable' to regs. Plod spot it; and they KNOW they have a fairly good chance of nailing rider for 'something'; even if they cant prove its de-restricted, and with the 'opportunity' of an incorrectly displayed front L, undersized or damaged rear L.... they have an 'invitation' to pull the rider; open with the "Do you know why I have stopped you, Sonny?" line fishing for admissions, then go over the bike looking for anything 'dodgy'.

b) XT500; No L-Plate, shouldn't need one, on Data-base, registered to some-one who DOES have a full licence to ride it; insured for that person with full licence; BUT being ridden by 15 year old......... bike is NOT reported as 'Stolen', so when plod spot it, there is nothing 'immediate' that they have got to justify a 'tug'........ especially if the kids inside a full face hat, and not doing anything 'daft'.


Add on Ed: Mate of mine with a DT he got for green-laning reckoned he was 'pulled' on average about once a week; and they ALWAYS used the line that the bike fitted description of one reported stolen; which if you think about it, gives them pretty much carte-blance to justify pulling almost ANY bike; but with so many Learner-Legals nicked, and dirt bikes particularly targeted; it's one they could a lot more readily defend for pulling a Dirt-Bike. Heard other DT owners echo similar experiences.
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G
The Voice of Reason



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PostPosted: 15:26 - 27 Sep 2011    Post subject: Reply with quote

Yes, if you're going as far as cloning a plate.

I rode around on a CRM125 for a while, no l-plates and did use it for green laning (so often muddy, etc). Never had any problems.
Nor did my mate who had a DT125, no l-plates again.
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ClockworkJesu...
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PostPosted: 15:46 - 27 Sep 2011    Post subject: Reply with quote

Doesn't take much to get pulled.
My brother's got a GS500E. Full license, perfectly legal.
The other day, he got pulled because, whilst he was insured, the insurance company failed to update the MiD's records. Thumbs Up

if they pulled my bike with no L-plates for a similar problem, they'd find I only had a provisional. No L-plates means no license (I think) and, that means trouble.

Would prefer to take my test and get a 600cc; than ride a 250cc illegally. Wink Just me though.
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Teflon-Mike
tl;dr



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PostPosted: 16:25 - 27 Sep 2011    Post subject: Reply with quote

G wrote:
Yes, if you're going as far as cloning a plate.


I didn't say that, did I? But yeah. If your breaking the law, your breaking the law & many ways to skin a cat.

If you want to ride something you don't have licence for, its what means there are to avaid detection. Modding a bike that on 'paper' looks legit is one way, leading to full on ringing. Then there's cloning. But thats all 'on the bike' trying to conceal the BIKES identity; actually easier to simply conceal the riders ident! Mate of mine rode for years on bike registered & insured in his big brothers name; if he got stopped; gave bro's DOB and details; and accepted a producer; then 'borrowed' big bro's licence to take to the cop shop. Of course that was the days before photo-cards....

G wrote:
I rode around on a CRM125 for a while, no l-plates and did use it for green laning (so often muddy, etc). Never had any problems.
Nor did my mate who had a DT125, no l-plates again.


The common factor being?

George; mate with DT did reckon that his tug rate dropped of by 3/4 when he passed his test!
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G
The Voice of Reason



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PostPosted: 16:29 - 27 Sep 2011    Post subject: Reply with quote

Teflon-Mike wrote:

I didn't say that, did I? But yeah. If your breaking the law, your breaking the law & many ways to skin a cat.

Ah, I presumed that was the suggestion in the second example, but you meant actually the same bike - which seems a lot less likely the other people would go along with it.

Generally (thus the mention of no l-plates), I've seen quiet a lot of people have issues with riding a 125 with no l-plates because the cops presume it should have them.
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P.addy
Red Rocket



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PostPosted: 16:33 - 27 Sep 2011    Post subject: Reply with quote

G wrote:
Generally (thus the mention of no l-plates), I've seen quiet a lot of people have issues with riding a 125 with no l-plates because the cops presume it should have them.


RS125 was tugged twice in a week Laughing

No other bikes without L's have been an issue... CBR or CLR... but the RS, probably down to the buzzing noise Laughing
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stevo as b4
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PostPosted: 17:53 - 27 Sep 2011    Post subject: Reply with quote

If you really want to get a bit more power from a DT125R engine and you have the money to spend, then rarther than an engine transplant for a difficult to fit 250cc non autolube MX motor that is really not very well suited for a road bike, then i would look at:

1, Fitting an Athena 170cc top end. This should only be done on a low mileage well looked after bottom end thats been fed decent fully synth oil, or on a brand new crank/connecting rod assembly or after the original crank has been re-built.

2, Looking for a DT200R engine, or a DT230 Lanza engine. Both are likely to fit into the std frame and use the same mountings etc, but finding either engine won't be easy or cheap. The 200R used a twin radiator set up which suggests the DT125R rad is marginal for anthing bigger than 125cc. And the DT230 Lanza engine is very rare, being fitted to a grey import only bike that was never anything like as popular as a KDX250 let alone a CRM250.

It also has an electric start, and the wiring is likely to be a pain as well as needing the correct CDI, Coil etc to get it to run and then you need to match up all the wiring for the rest of the electrics to the DTR set up. Big pain and potentially lots of expense involved too.

I do agree that if a properly fully de-restricted and in decent mechanical condition DT125R is not satisfying your needs, then it's really going to be much more economical and viable to sell it and buy a bigger trail/enduro bike that does!

Lastly i've learned the hard way over the years by wasting money a plenty on small capacity bikes/scooters trying to modify and tune them for more speed and performance. You never get a 100% satisfactory machine once you start messing around and modifying things much different to the original spec.

I always say now that the best bikes to tune are the ones that are already much faster than you need/want or can use realistically.

If you have a 150bhp superbike thats already massively quick and has much more potential that you can safely or legally use, then you can never be dissapointed if you add another 20bhp from tuning it, as your never going to use that extra power or feel it's that important to have.

Tune a 125 and expect another 20mph extra top speed and you will nearly always be dissapointed and probably totally skint too!
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dangerousdave
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PostPosted: 17:58 - 27 Sep 2011    Post subject: Re: im thinking about upgrading engine size in my dt125 Reply with quote

mivster wrote:
im thinking about upgrading engine size in my dt125
i was thinking about a 200-250 cc
is this possible how hard is it to do and will will i need to change anything else. also any ideas which engine to use
i want to stay with a 2 stroke engine
thanks


What about just fitting a big bore kit ?

https://www.myscooterparts.co.uk/motorcycle/athena-cylinder-kits/scooter/motorcycle/athena-big-bore-170cc-cylinder-kit-with-head/vz60206/

not that cheap, but the easiest power you'll get IMO.

you could no doubt fit a bigger engine but the amount of work will increase dramatically depending on which bike it comes from.

a dt200r engine would probably be the easiest straight swap, you'd need to use the exhaust, carb and possibly the airbox too to get it running well. They are import only, so pretty rare though.

If you can fit a motocross engine from a YZ 125 or 250 it would be great fun while it lasts, but remember service intervals on the piston are 50 hours and crank 200.
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Teflon-Mike
tl;dr



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PostPosted: 19:23 - 27 Sep 2011    Post subject: Re: im thinking about upgrading engine size in my dt125 Reply with quote

dangerousdave wrote:


I've heard mixed reports on the LC big bore kits.

On the earlier air cooled motors; it was a direct swap for factory 171 barel... EXCEPT..... it wasn't. The auto-lube oil pump used different ratio drive; carburettor was a different size; I believe it had different reed-block, and a different CDi unit.... Just swapping barrels usually didn't resulty in any significant power gain; motor strangled by reed block, carbs and ignition, and running weak, and starved of oil, often prematurely siezed. And that's the 'simple' air cooled motor!

On the LC's when over bored there is a pottential problem in the power valve actually fouling the piston in teh closed position, if there is ANY wear in the PC shaft bushes, and its reccomended to modify the actual power valve itself for extra clerance, even if fitted with new bushes. Cooling capacity has been mentioned; and I suspect that oiling, carburation & ignition issues to get best out of big bore remain as per the air-cooled engines.

Odd reports I've read of the big-bore barrels on LC's is that I've come accross, have suggested that gains are 'dissapointing' or the bike's just kept 'blowing up'....

Which hints that ideas are possibly correct; big bore alone; boosts bottom end a bit, but without bigger carb & other mods to let it breath the extra capacity, no more at the top end; and not used hard, saves overheating or siezing issues; carbed to get the top end; limits of oiling & cooling start to show.
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mivster
Crazy Courier



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PostPosted: 20:24 - 27 Sep 2011    Post subject: Reply with quote

all it is ive just got a dt125 dog rough with a screwed engine so was just wondering is it worth doing so i can have a mess offroad with it
please dont jump to a conclusion i want to ride illegally as thats not my intention at all
ive got a road legal dtr125 im fully happy with and enjoy but its my baby and i dont wanna get it dirty lol
so in short with peoples opinions im guessing its not worth doing
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