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De Restricting my DT125R

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Yes the cdi is restricted on post 98 bikes. Yes there is a way around this, but its in German.(the link is further up this thread)

Vez

I suppose the only way to get one of these to full power would be to use the pre98 PVservo, cdi and modify a post 98 loom to suit. With a good pipe and the 240 main you should be looking at proper power. Maybe even use a pre 98 pot and head too as there may be different compression or porting too.

Bit drastic for OG and 2wheels tho.

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Guest MaD.VeZ

I suppose the only way to get one of these to full power would be to use the pre98 PVservo, cdi and modify a post 98 loom to suit. With a good pipe and the 240 main you should be looking at proper power. Maybe even use a pre 98 pot and head too as there may be different compression or porting too.

Bit drastic for OG and 2wheels tho.

Not sure there is any difference in the head/barrel since they changed from the old style in 89, 3DB to 3MD. The part numbers are the same on the 97 and 04.

There is also the inlet manifold that is another restriction.

I think with a gutted pipe and reed switch moved it should be fine for OG.

Just wondering, but does your TDR have a PV Cynic?

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Not sure there is any difference in the head/barrel since they changed from the old style in 89, 3DB to 3MD. The part numbers are the same on the 97 and 04.

There is also the inlet manifold that is another restriction.

I think with a gutted pipe and reed switch moved it should be fine for OG.  

Just wondering, but does your TDR have a PV Cynic?

In the words of that stupid mutt on the adds OHHHHHHHH yes.

Only problem being as its a twin it is VITAL that the powervalves are kept in perfect condition and adjusted, any imbalance or leaks and the bonkers power is gone.

Its the 250. And its the same system as the pre 98 125. I have seen it mentioned but have absoloutly NO evidence to back it up that the barrels will actually swap.

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In the words of that stupid mutt on the adds OHHHHHHHH yes.

Only problem being as its a twin it is VITAL that the powervalves are kept in perfect condition and adjusted, any imbalance or leaks and the bonkers power is gone.

Its the 250. And its the same system as the pre 98 125. I have seen it mentioned but have absoloutly NO evidence to back it up that the barrels will actually swap.

Using the same barrels sounds like something Yamaha would do.The part numbers are 3MB00 and Y-1 for the DTR barrel, expecting them to be the same number would be a stretch but you never know. IF they do swap, i wonder if you could get two of the Athena 170 kits on there.   :lol:

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Found a vid of how the PV should be. When i got my DT125RE the valve was 180 from this, and thats from the dealer.

http://www.youtube.c...h?v=UsWwQssiK-w

I think if someone with a cbt buys the bike, the dealer may restrict it to comply with regs, or de-restrict it for a full license holder. just a theory though.

Also found a site to buy customizable CDI, that may be worth adding to Ryans Guide. 130 Euros though. http://www.ignitech....lish/aindex.htm

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Dunno about my power valve (whether its in the right way or not), will check that out later

However back to the exhaust

1: Thanks Vez for the spare exhaust, overall its a good one which is unusual as the headers are often shot through neglect with repainting and cleaning.

2: Took said exhaust to a local engineering / welding oufit today and instructed them to chop it in two so i could remove the internal sound absorbing mesh and restrictor rings

3: Arrived back an hour later to find that theres nothing whatsoever in there :o

4: so i wasted my time and money on that little exercise, and apparently the older DTR's ie 88 - 96 dont have these things inside but do still have the header restrictor :(

Well at least now its in two pieces i can power wash the carbon out of it :)

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Dunno about my power valve (whether its in the right way or not), will check that out later

However back to the exhaust

1: Thanks Vez for the spare exhaust, overall its a good one which is unusual as the headers are often shot through neglect with repainting and cleaning.

2: Took said exhaust to a local engineering / welding oufit today and instructed them to chop it in two so i could remove the internal sound absorbing mesh and restrictor rings

3: Arrived back an hour later to find that theres nothing whatsoever in there  :o

4: so i wasted my time and money on that little exercise, and apparently the older DTR's ie 88 - 96 dont have these things inside but do still have the header restrictor :(

Well at least now its in two pieces i can power wash the carbon out of it  :)

1. Your welcome Paul.

3. What makes it weigh that much then. The walls 1/2" thick ? or is there alot of carbon in there  :lol:

Has it got the same part number as your original?

When its sorted you will have to let us know how it compares to your other exhaust. 

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Dunno about my power valve (whether its in the right way or not), will check that out later

However back to the exhaust

1: Thanks Vez for the spare exhaust, overall its a good one which is unusual as the headers are often shot through neglect with repainting and cleaning.

2: Took said exhaust to a local engineering / welding oufit today and instructed them to chop it in two so i could remove the internal sound absorbing mesh and restrictor rings

3: Arrived back an hour later to find that theres nothing whatsoever in there ohmy.gif

4: so i wasted my time and money on that little exercise, and apparently the older DTR's ie 88 - 96 dont have these things inside but do still have the header restrictor sad.gif

Well at least now its in two pieces i can power wash the carbon out of it smile.gif

Which pipe did you get chopped then ?

The one Vez gave you or your own original ?

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Think it was the one he got from me 2-wheels.

A then, that is also good to know that the 88 - 96 dt didnt have all the crap built in them like the newer ones.

Ta Vez

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Sorted out my PV today. :D

on removal of the pulley and exhaust i found it to be in the restricted position.By sticking a finger in the top of the exhaust port it could be felt that there was a hollow groove between the port and the PV. This is because the PV needs to be turned slightly more and will then be a smooth passage through port to cylinder with the pulley aligned with the 4mm hole in the cylinder. There are two possible positions to mount the pulley onto the PV, hopefully the pics will make it clearer.

Pic 1, Pulley removed and this is the position as found (Restricted)

102_1434.jpg

Pic 2. Back of pulley showing how the PV would sit in the restricted position.

RestrictedPV.jpg

Pic 3. Back of pulley showing how the PV would sit in the un-restricted position

DeRestrictedPV.jpg

I can report a definite improvement now and the bike is much more willing to rev freely.

Cant give it beans yet as due to still running in so revs not going much over 6k at the moment.

DEP silencer is on order and a 250 main jet. I believe standard is 240.

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Guest MaD.VeZ

Excellent post Paul, I would like to add a few points though.

Firstly the PV can sit in 4 different positions, either one of your picture examples can be set 180 degrees out. This has caused me no end of headaches in the past and is why I find its always best to do the PV with the exhaust off so you can get a visual on it.

Second of all as far as I'm aware the standard main jet for the DTR with the Mikuni carb 3MB00 is a 210, IF you have a different carb then they could be 240, as a 240 is what i would go up to with mine.

Vez

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Nice work Oldgit

Yea I second that, Vez

Standerd main jet in a Mikuni carb is 210,

Dont think a 250 rather than a 240 would be much of a prob.

So she feels much better now then, eh Paul

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Excellent post Paul, I would like to add a few points though.

Firstly the PV can sit in 4 different positions, either one of your picture examples can be set 180 degrees out. This has caused me no end of headaches in the past and is why I find its always best to do the PV with the exhaust off so you can get a visual on it.

Second of all as far as I'm aware the standard main jet for the DTR with the Mikuni carb 3MB00 is a 210, IF you have a different carb then they could be 240, as a 240 is what i would go up to with mine.

Vez

Where is the carb number, i cant see it?

I have been told my bike as a 4BL import would have a 240 jet as standard. I have ordered a 250 on the strength of this, maybe a 260 will be considered too.

You have me wondering now on the power valve although it did seem to be running right. look at this picture, If the PV was upside down there would be a bulge in the exhaust port, rather like a 'sleeping policeman' if you know what i mean, and it would have the same effect too no? To slow it down. I wish i had rotated it round though now.

PV.jpg

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So she feels much better now then, eh Paul

Way better now with the exhaust tube gone and the PV set (hopefully) correctly. Should be better still with the DEP silencer :D

. ...But i'm running in so wont be getting the full benefit. It just rev's more freely which is what i was wanting but keeping less than 6k at the moment. :rolleyes:

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Where is the carb number, i cant see it?

I have been told my bike as a 4BL import would have a 240 jet as standard. I have ordered a 250 on the strength of this, maybe a 260 will be considered too.

You have me wondering now on the power valve although it did seem to be running right. look at this picture, If the PV was upside down there would be a bulge in the exhaust port, rather like a 'sleeping policeman' if you know what i mean, and it would have the same effect too no? To slow it down. I wish i had rotated it round though now.

PV.jpg

I quite sure you have the PV right from how you described to me earlier. It was more to help anyone else who should find this thread in future. Yes you are right about the sleeping policeman bit(there is also a horizontal channel in the PV that you can feel,no idea why), its obvious when you have the exhaust off. If you try to just remove the PV servo cap and turn it then it can cause issues, as you get a lip that distorts the flow and causes the bike to run like bag of spanners, if it starts at all.

I have checked the carb I used for the pics the other day and can't see any ID marks (3MB00 is from the manual), I will check my bike tomorrow in the daylight and let you know if there are any on there. It would seem strange to have a 240 main as standard with all the restrictions. If it were me i would have the carb off to make certain.

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I have looked at my carb, there are no markings on mine either only the name Mikuni.

My engine no starts with 4BL.........

My frame no starts with JYA4BL..........

On the left side of my piston barel there is 3MBOO stamped.

I talked to a mate of mine and he said that the standerd main jet changed from 210 to 240 from the year 1999 onwards.

So maby you are right Oldgit

When I had my carb off for cleaning ages ago I prob did look at main size but for the life of me I cant remember what the hell it was.

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I have looked at my carb, there are no markings on mine either only the name Mikuni.

My engine no starts with 4BL.........

My frame no starts with JYA4BL..........

On the left side of my piston barel there is 3MBOO stamped.

I talked to a mate of mine and he said that the standerd main jet changed from 210 to 240 from the year 1999 onwards.

So maby you are right Oldgit

When I had my carb off for cleaning ages ago I prob did look at main size but for the life of me I cant remember what the hell it was.

Lots of the DTR parts will have a 3MB00 as its the identifying mark. There should be another number on the other side of the barrel ( Y-1 for the barrel and Y-2 for the head iirc). My RE has the same number on the exhaust, even thought the exhaust is completely different to the DTR. I think Mikuni's carb identification number is VM26SS but its the same for the old style round carb as the flat sided one, so doesn't help in identifying a carb. Looked at my RE carb this morning and its void of ID marks too.

It doesn't sound logical to me to change to a larger jet when the are adding restrictions. But there are lots of illogical things Yamaha do that baffle me.

Edit:The only reason i could think to change to a 240 is because the post 97 UK model had the PV servo fitted. Would make sense i suppose :lol: So it leaves me wondering is a 250 enough for the DEP OG has ordered.

Edit 2: Have you moved the reed switch yet Paul as some pics would be good?.

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I have looked at my carb, there are no markings on mine either only the name Mikuni.

My engine no starts with 4BL.........

My frame no starts with JYA4BL..........

On the left side of my piston barel there is 3MBOO stamped.

mine is also a 4BL### and JYA4BL###

so yours is an import too then and will be restricted in the same way as mine, mine is a French bike it has a km/h speedo and i will put money on it that i will have to replace the headlamp...even though it has just been mot'd. i'm just hoping they will mot it next year with a miles / kilometres converter fitted and a few stickers on the face.

It doesn't sound logical to me to change to a larger jet when the are adding restrictions. But there are lots of illogical things Yamaha do that baffle me.

Edit:The only reason i could think to change to a 240 is because the post 97 UK model had the PV servo fitted. Would make sense i suppose :lol: So it leaves me wondering is a 250 enough for the DEP OG has ordered.

Edit 2: Have you moved the reed switch yet Paul as some pics would be good?.

I will be fitting the 250...assuming of course i find a 240 in there when i check. If its too big no worries i would rather that than too small. As for the reed switch i dont even know if it has one fitted yet with it being an import but i will check it out all in good time ;)

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If the headlamp is angled to one side (if in fact they do like cars), then can't you just flip it upside down to comply with the UK mot? Theres alot of adjustment even if you can't just flip it. Or is there something else i don't know about with headlight laws? 

And what i was thinking with the 250 main jet is, will it will be big enough for the DEP if a standard is 240 ?.

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