De Restricting my DT125R

[Airhead]

Like I said though its going to be a long time off, i'm not pulling the head off just to do that so will do it when theres another reason to do so.

Well that was yesterday, today my 3MB head, inlet manifold and reed cage arrived. will get to work on the reed cage and manifold, I now doubt very much that i will wait that long to change the heads, it will be done this year at least...

[Cynic]

Well that was yesterday, today my 3MB head, inlet manifold and reed cage arrived. will get to work on the reed cage and manifold, I now doubt very much that i will wait that long to change the heads, it will be done this year at least...

Before or after the 175?

[Guest MaD.VeZ]

Thats one strange looking squish band, why the hell do Yamaha do sht like that. From the look of it the effects would totally remove the point of a squish band and trap the mixture at the edges.

The later models don't have the same squish as that(unless its just imports, either way its weird).

Vez

[Airhead]

Before or after the 175?

Must admit i've enjoying the challenge and tinkering with the 125, anyway I cant work in my garage and its usually too cold to work outside on the 175

Thats one strange looking squish band, why the hell do Yamaha do sht like that. From the look of it the effects would totally remove the point of a squish band and trap the mixture at the edges.

The later models don't have the same squish as that(unless its just imports, either way its weird).

Vez

I have learned a lot of things from this French webforum, they really do know their stuff, its a little difficult with the language at times but has been well worth the effort

http://yam2stroke.0rg.fr/index.php?sid=c8bedfc4a4c1646326a2bcba6c88e5b9

Anyway, like I said earlier I need to fit a larger jet when I fit the silencer but because the carb is tricky to remove I wanted to sort out the spare reed cage and inlet manifold I bought.

Referring again to things learned on the 'yam2stroke'

here http://y2s.free.fr/bac%20et%20pipe/bacetpipe.pdf

I have done the work to the reed stops and the inlet manifold.

I have seen on other forum and even a mention of it on this one, something about cutting all the robber moulding out of the inlet manifold where it goes inside the reed cage, after consideration though I decided not to do that and to just do as suggested at yan2stroke

Befores

Afters

One before and one after

All ready do be fitted now with the jet, the boyesen reeds and the DEP silencer.

[Airhead]

Did the rest of the work today.

Fitted

Boyesen 2 stage reeds, omitted the reed stops as not required.

Modified inlet manifold, although i am sceptical that this is of benefit.

250 main jet.

DEP silencer.

Looks good, sounds good and goes really well for a 125. this is the bike I hoped I had bought back in January. Only thing left now is the snorkel but i'm going to cut it shorter rather than remove it completely...and the 3MB cylinder head.

[2 Wheels]

Good job OG.

Bet it is alot more responsive now eh !

Did you block off or take away the black air bottle on top of the inlet.

I must get at mine now again and do the rest of the stuff you have done.

I just need to get a 250 main jet some where, Oh and pratice my mig welding for my exaust.

Now can i have a pic of the end of you DEP and the with of the hole in mm, Pritty Please

Pat

[Guest MaD.VeZ]

 Nice one OG, so much for having to wait for weekend.

Talked to a kid at college with a DEP yesterday and his has the sticker on the same side as yours  

*chants* pics pics pics.

[Airhead]

Good job OG.

Bet it is alot more responsive now eh !

Did you block off or take away the black air bottle on top of the inlet.

I must get at mine now again and do the rest of the stuff you have done.

I just need to get a 250 main jet some where, Oh and pratice my mig welding for my exaust.

Now can i have a pic of the end of you DEP and the with of the hole in mm, Pritty Please

Pat

Cheers Pat, There are several schools of though regarding the YEIS 'boost bottle'

1; To tune your bike up take it out, it's Yamaha's underhanded attempt to restrict your bike.

2: To tune your bike you need to fit a 'Boost bottle' as developed by Yamaha back in the 70's

i'm with 2:, I dont believe that Yamaha would have developed these things and continued to fit them to their bikes with extra production costs if they are of no benefit, they certainly were developed as a tuning aid, never as a restriction. The benefit may be small, even un measureable but i dont believe they are detrimantal.

The silencer is a different type altogether, its just a perforated tube with exhaust packing, quite commonplace. But the original is a different story, it is full of tubes to divert the exhaust gasses this way and that before it exits, there is a name for it that escapes me at the mo (its my age y'know)

I would recommend you buy new or used another rather than mess with the one you have.

 Nice one OG, so much for having to wait for weekend.

Talked to a kid at college with a DEP yesterday and his has the sticker on the same side as yours  

*chants* pics pics pics.

Vez will post pics but havent taken any, it was going dark when I finished. As for the stickers yes i phoned them and they are all like that now so i'm past caring, still looks good.

[Guest MaD.VeZ]

Im with OG on the boost bottle 2-wheels, they were there before the restrictions came in proper so i don't believe they are a restriction. The second one connected to the air side of the carb maybe though, blocked it up on my DT125RE and didn't notice any difference tbh. 

I wouldn't bother trying to modify the silencer, i have tried and gave up, there is just too much inside.(would be easier to make one). Still got it cut open in the shed somewhere, will post some pics of it so you can decide for yourself mate.  

[Airhead]

The second one connected to the air side of the carb maybe though, blocked it up on my DT125RE and didn't notice any difference tbh. 

Second one? the black plastic bottle out the top of the inlet manifold is the one. they are always on the air side arent they?

[2 Wheels]

A then,

Cheers for the heads up on these points.

Will get to work on the rest of the stuff.

[Guest MaD.VeZ]

Second one? the black plastic bottle out the top of the inlet manifold is the one. they are always on the air side arent they?

There is a second bottle on the air inlet for the carb (air filter box to carb) on some of the newer DTR/DTRE/DTX 's, think you can see it in the vid AndyDTR08 posted. I have seen DTR's with these fitted.

Found a pic. not to clear though

[Airhead]

Whooo! dont think mine has that one...when you get a new bike i'll have a look at that one.

Theres one on ebay...Openshaw

if you want a look i'll run you down at weekend.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=260569660813&ssPageName=STRK:MEWAX:IT

[Guest MaD.VeZ]

Insurance haven't payed up yet, will phone them Friday if they don't phone me by then.

Got a few insurance quotes for the sachs and they came in around £800tpft, may be off the road for a while even if they pay me for the DT. Its alot more to insure a DT so getting another is probably out the window at this point. If they don't pay i'm screwed and taking the bus again.

Thanks for the offer though Paul.

[Airhead]

"pics pics pics"...ok if you insist

Boyesen reeds

DEP silencer.

The commute to and from work is a lot more fun lately

[2 Wheels]

Looks goooooooooood

I thaught the DEP might not look good because of its colour but I was wrong.

Tis all good OG

How many more run-in miles have you left to do?

Does it make going to work feel a lot better

[Guest MaD.VeZ]

Yup i insist on pics.

Excuse me a moment .

The DEP looks spot on, Yamaha should have made them standard

Going to work should run the miles off soon enough.

You got any more mods planned(except the cylinder head that is)? *cough* Renthals *cough*

 

[Airhead]

Does it make going to work feel a lot better

Going to work is a lot better yes, but coming home.........awesome!

BTW Happy st Pat's day mate.

You got any more mods planned(except the cylinder head that is)? *cough* Renthals *cough*

Thats a bad cough VeZ, yep Renthal bars are a good mod, like the look of them myself too, maybe braided brake hoses too.

[CameronMac]

Going to work is a lot better yes, but coming home.........awesome!

BTW Happy st Pat's day mate.

Thats a bad cough VeZ, yep Renthal bars are a good mod, like the look of them myself too, maybe braided brake hoses too.

So I just read through this thread and I have a quick question. I have my 175's exhaust off at the moment and I'm wondering if this would be a worthwhile thing to do while I'm waiting to get the barrel back. On my '79 would it just be a matter of getting off the piece in the exhaust and upping the jet, or is there a lot more too it then that?

[Guest MaD.VeZ]

 

Thats a bad cough VeZ, yep Renthal bars are a good mod, like the look of them myself too, maybe braided brake hoses too.  

I wouldn't bother with a rear braided hose mate, didn't make alot of difference on my 97, the front on the other hand made a huge difference. But i guess your going for looks aswell as performance. Got a link to some somewhere ill post it when i find it if you like.