Another New Guy
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@d3cme My DTR was a 2002 and when I removed that boost bottle the bike did not accelerate as fast, plus I lost 10mph off the top speed. As soon as I put it back on the bike was fast again. Now having no bottle may not affect Rpm's but it did slow the bike down. However if the CDI is mapped for a boost bottle, then surely the lack of one would affect the bikes performance???
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@NINJA said in Another New Guy:
@d3cme There are restrictions in the exhaust front pipe too, which can only be removed by cutting it open and welding it back up. A straight swap to an aftermarket exhaust is easier and may be cheaper too.
Is there a way of checking? I think I saw that the 2002's have it in the larger part of the exhaust as opposed to immediately in the neck? Will I need a new gasket? I'll borrow a borescope in and see if I can make anything out.
Seen some bits about flipping the PV 180 degrees? Any truth in that?
2002 DT125R - Black
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@d3cme You can remove the front pipe and literally stick your finger up it
To feel for any restrictions, or use the borescope as you've suggested. OEM's build bikes to meet omission laws etc and therefore have restrictions in place whereas aftermarket parts remove those restrictions. It's just like the Catalytic converters on cars, they create a honeycomb/blockage like effect to slow the gasses down. Remove the cat and the gasses flow out quicker.You would be better off just getting a new pipe like a DEP, Giannelli, Arrow etc. And keep your stock one if you ever come to sell it, as most of the restrictions are in the exhaust. Or if you want the ultimate in looks and performance then go for a Romeu pipe;
As they are not only hand made but they will outperform, outlast and look simply amazing on any DTR, as well as adding value. Personally I would not waste any more effort on this, just follow the derestricting guidelines, order that bad boy and be a happy biker 24/7!!!
SEDUCED BY THE DARK SIDE!!!
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Thanks All,
I think a certain amount of this is managing my expectations. I used it for work today and it was great, I think its just not got the 'kick' I was expecting from the YPVS. I'll have a look at the PV tonight and take the exhaust off to see whats what!
I was actually eyeing that exhaust up earlier @NINJA, looks very nice!
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@Calum said in Another New Guy:
@NINJA Stock pipe. The amount of weight saved by going aftermarket is probably where 90% of the noticeable power comes from I swear!
The FMF on my DT200WR is like a feather in comparison to the stock one which weighs a tonne!
Go after market every time
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So I may have sorted my problem... I say may, because it makes sense but am yet to test.
On another forum I found some posts from about 8 years ago outlining someone else’s derestriction journey. Looks like he had a 2003 french import DTR, so very close to mine.
He found that the Powervalve under the pully was a diamond shape and needed turning to a derestricted state as it wasn’t flush with the exhaust port. Now I’d seen mention of a diamond shape thing somewhere and also mention of turning the powervalve but didn’t really understand what it meant. There was also a restriction in his 3MB-14160 expansion chamber just like the older models straight out of the cylinder.
I was working last night so had some time this afternoon to take a look, and found my powervalve had this diamond shape on the end, and after getting the exhaust off I could feel that it wasn’t flush in the port.
Now that I’ve aligned it all, and run it up the servo is back to normal (it was a bit sticky straight after turning so I guess things were gunked up where they shouldn’t be).
Annoyingly I can’t ride it currently as the gearbox oil cap is all chewed up and I had already dropped the oil and taken it out by the time I realised. Hopefully a replacement will be here tomorrow.
Initially though it seems much smoother and revs more freely after warming it up a bit, but won’t know for sure until I ride it. I guess with the powervalve being out of line entirely it would have been restricted right through the rev range and ‘wide open’ still restricted as much as fully closed?
Not sure if this means I’ll need to rejet... biggest worry currently so will keep an eye on the plug. Couldn’t see anything in the exhaust so hopefully be much better now.
Sorry for the long post, will get a few pics up later to hopefully make sense of it all..
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@Calum said in Another New Guy:
@d3cme I haven't seen a powervalve that wasn't a diamond. I always recommend taking the exhaust off and matching it against the exhaust port.
I saw some pictures where it was rectangle and totally filled the slot, not sure on year etc though that the pic was from.
Bikes are new to me, cars I’m fine with but I was apprehensive about taking the exhaust off. I ordered a new gasket but it didn’t seem to have one in to replace? Absolutely the best way and only took a couple of mins.
