DT125 Intake Manifold Restrictor?

[RudiRulez]

Been reading up on it, most say its a restrictor but some complained that they had lost a few mph off their top speed once they had cut it off, has anybody got a real picture of what the intake manifold actually looks like with the 'restrictor' still attached? All i have to go by is the amatuer drawing on dtr125.net, is it possible that this is to help the air-flow not restrict it OR maybe the people who removed it lost power because it was a restrictor but now their bike is running too lean and all they need to do is upjet the feel the benefits, can anyone help me to make the decision to cut it off or leave it be?

https://i83.photobucket.com/albums/j312/Rudi1992/inletmanifold.jpg

[MattHirst]

They may well loose a bit of topend, afterall you will be letting in more air so the A/F mixture will be out.

You will need to rejet after doing that.

Can't help on exactly what needs to be taken off/cut off though.
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It's all fun and games until someone gets hurt, then it's bloody hilarious!!!

[RudiRulez]

[bikersupermot...]

hey rudi - can u let me know the outcome of wot u do? ...

also, wots the set up of your bike just now?
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tinybikes

[RudiRulez]

[bikersupermot...]

hey rudi - just to let ya know ... on my 2004 dt125x, i took the full dep pipe off, fitted an older (early 90s) front pipe, and a fresco tail pipe.

the bike runs sooo much better like this, reasonable mid range pull compared to nothing before ... (town riding was dangerous it was so slow - it cudnt pull the skin off a rice pudding!) ... its got a "nice" noise an hopefully less likely to attract attention of mr plod now ... and im still getting 80mph out of it (on the bike's speedo - dont know how accurate it is - needing a gps unit to measure it better).

id still like more bottom end grunt tho - my dream wud be to fit a yz250 engine into it ... or just get a cr / crm 250 and supermoto it! .

but my dep set - up was really bad and the bike ended up melting the piston ring into the piston and backfiring all the time with the dep set up (i bought the bike with it already on). i got a kmx125 that runs soooo nice with the standard pipe and is faster than the dtx - (wud luv to know wot previous owner did to it!)

anyways, lemme know how u get on with yrs!
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tinybikes

[ben350]

Pictures crap and I cant remember off the top of my head what the inlet looks like, however lots of bikes had some kind of 'stuffer' in them to reduce dead air / aid air flow. Before you cut it off be sure
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Ducati 996 Biposto
Suzuki Goose 350
DT125R Supermoto (Project)

[baldy]

That does not look like a restrictor. I think it's to help the air flow, which is why people lose some speed when they cut it off. Normally, things that have to be cut off are meant to be there.

[RudiRulez]

[feckless]

i di that mod to my sons bike and the midrange pull was far better and it actually increased the top end speed on his bike.
its an 03 model and it had a restrictor in the exhaust at the point where it mates with the barrel.
removing this is the best mod you can do.
it sounds like a 2stroke should now

[ben350]

I wonder if it was actually faster or it simply felt quicker as it was making loads more noise

BTW I've checked and all the reed blocks I have for the old DT-R's have that extension piece
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Ducati 996 Biposto
Suzuki Goose 350
DT125R Supermoto (Project)

[feckless]

according to the speedo it was faster
i did a before and after run on the same stretch of road within 1/2 half hour of each other.