Dt 175 1g1 carb choice

[Dirtygirty]

Hi all.
I'm after a new carb for the bike been looking at the nibbi pe24 or pe26 from Misano moto imports, if any of you guys have a opinion on carburetor choice I would appreciate it.
They use keihin jets, if anybody knows the keihin equivalent of mikuni 130 main jet and 25 pilot it would be a great help, I've spent hours looking at posts trying to work it out, general opinion seems to be that the conversion charts online are incorrect.
Cheers girty

[Easy-X]

Hello m8y, took a while for you to turn up here Could you not get on with the flat-slide? (BTW, for future reference more of a "Workshop" thread.)
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Dirtygirty]

Hi mate wonderd how long it would take you to find me, that pwk Is good for top end power but if I'm gonna do some greenlaning I think a smaller carburetor would better for torque.
Plus I think that carburetor has got an even bigger drink problem than big ian and that man can seriously put some methanol and coke away.
Have you looked at the nibbi pe26 .
I measured up the carb throats I got, the mikuni is 28.5 the pwk 27.5 and the vm 26.8 might try the vm if I don't get another carb.
Cheers for now.

[Easy-X]

Someone will be along in a minute to convince you to sell it and buy a Bullet instead Seriously though I guess the PWK is intended for a more modern engine with power valves and the like.

IIRC the factory spec is a Mikuni VM24 but a VM26 is the same outer diameter just bored out more... the Nibbi looks like a jazzed up knock-off, certainly worth a go. Maybe consider the PE24 instead? Smaller = faster response (but less top end.)

There's always the basic drop a tooth on the front, add some teeth at the back.

<edit> and there's also dropping the compression but you're already on that?
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Dirtygirty]

That vm carburetor has got a weird pilot jet I can't find one for it anywhere it's not mikuni or keihin will probably need a #30-35, its 20mm long the ones I've seen that might fit are 28mm long, the standard jet for a vm24ss carburetor is #25.
I'll keep scratching my head, sure something will come to mind, I'll give it some thought, but the last time I though, thought to long and pood myself.

[hellkat]

Can we not just call you "Dirty" instead?
Much easier.
With a glottal stop, of course.
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Not nearly as interesting in real life.

[Easy-X]

[Dirtygirty]

You can call me anytime, as long as it's dirty.
I thought about the mikuni but it's just such a big one .

[Dirtygirty]

Checked out that site the pilot jet is different, the jet in the vm hasn't been bored rite through so it wouldn't have run anyway.
I've committed and compromised and order the nibbi pe26.

[Easy-X]

[Dirtygirty]

Will do

[Dirtygirty]

Well the cylinder is back the carb has arrived, so it's time for some modding the carb has been drilled for oil injection.
The exhaust port has been reground to match gasket and polished to a mirror finish to stop carbon build up I've also polished the head, transfer ports had been previously ground to debure but the bridge in the port had been knife edged so I've taken the sharp edge of them I've also reground the transfer ports to match the crank cases as there was a 1-3mm overlap on the ports should get a better flow now, ground the reed valve inlet to remove burrs and some reshaping for better flow.
Filed the edges of the fins gonna paint cylinder and head black for better cooling then resand the edges so it looks sexy like me.
Saw a lnteresting post a couple of guys that raced Dt's in the stock class that they dominated, only mods allowed was exhaust end can, they ran the stock end can, they did some tests borrowing aftermarket end cans off some of the other guys, there tests with a stop watch and drag racing two bikes with both cans showed that the starndard pipe won every time, they got accused of using big bore kits and cheating by some of the other racers, but as matey said Yamaha got the exhaust rite the first time.
So I'm sorry Easy a standard cans going back on, got the original cut open at the moment gonna get rid of the gummed up packing give it a clean and weld it back together.
If you're about the weekend Easy I'll show you my carbatooter might even let you rubb it if you talk to me nicley.

[Easy-X]

[Dirtygirty]

Haha never gonna get a lot of power out of it, just trying to get it to do what the designer designed it do, more bottom end torque is what I want, unfortunately mass production never matches the the designers specs, I'm not tuning it,as much as blue printing which is what it should be out of the factory, but that's mass production of the 70's for you.
Cheers dude.

[Dirtygirty]

Well it's finally back together and up and running all new bearings and seals throughout the engine and gearbox, crank shaft rebuilt clutch was fine although I'm certain it has competition springs in it, definitely not yamaha springs I bought new springs but fitted the ones that were in it the new ones were crap.
First run didn't go well to start with, fitted the carb as it was when I took it of but it ran like a bag of nails, it had a 36 idle jet in it so I fitted a 40, got a little better, fitted a 45 better again but the air screw had to be screwed all the way in, got a 48 in it now it runs quite nice but the air screw is only half a turn out.
Run out of jets now I recon it will need about a 52-55 to get it rite.
Oil pump is pumping way to much oil, the plug is coming out black and wet round the outside but black and dry in the centre core I'll try adjusting it tomorrow and see if it helps with the running.
It might even get a road test tomorrow with it's new mudguards and polished cases and new footpegs got a new wax that leave a resin like coating on the cases and chrome saves laquering them.
That's it for now.

[Easy-X]

Nice! I've been wondering how you've been getting on but I've had mad time of it with work

The oil pump would need some shims on the end to alter the flow rate but you've gone so far off-piste I'm not sure where one would start on getting that right Still, better the pump's operating too well than not enough

Which carb is in this at the moment? 'Cos you've built up a bit of a collection by now
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Dirtygirty]

Hi dude, well at the moment were not that far of kilter from where the bike was before its still got the same exhaust the carb is now closer to original than it had before and the work on the transfer ports was only a matter of deburing and cleaning them up, l haven't actually altered the size or shape of the inlet ports in the cylinder.
I had another play with it today not much luck though, it seemed to get better but then it would get worse again, just can't get it to run nicely below 3000rpm consistently sometimes it will sometimes it will wont it's all a bit random think I'm going to fit the 40 jet again and start from scratch, if I can't get it to run rite then I might refit the big carb or the black mikuni I found a problem with the mikuni so it should be OK now.
Of course their could be something else going on.
The oil pump is set about rite according to the manual but I still think it's pumping to much oil.
It's a bit awkward with mum at the moment as she has a nap in the afternoon so I can't run the bike when I want.
I'll give it another go tomorrow after work if I can.
Cheers.

[Dirtygirty]

Hi easy, well I changed The carb to what it was before, it's running good now, time to run it round the car park runs nice gearbox is super super slick only got into third a couple of times, gets neutral first time every time, didn't do that before.
Rite road test time give it a kick starts first time ride it up to the end of the drive across Main road into slip road, first gear second gear boaaar nothing flat as a witches t1t gremlins knocking away at the cylinder head with a hammer no throttle response atall, get it home give it a kick starts first time won't rev.
Rite that's it I've had enough, time to get serious with it, so I gave it the Told it what I thought of it And went and had a cup of tea, well as always a cup of slurp solved the problem, started and ran perfectly again, decided to bite the bullet.
So I've refitted the original pwk 28mm carb the bikes now exactly as it was originally apart from a new condenser.
Give it another try tomorrow hopefully, it's starting to turn into the fosdyk saga.

[Easy-X]

Lol... that bike has carbs like some people have hats!

It sounds like it's just emptying the bowl BTW did you get any improvement on the fuel flow from the tank?
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Dirtygirty]

I've changed fuel line and got rid of the filter, but I do wonder about that fuel tap, had things gone to plan I was gonna fill the tank to the brim, I'm sure the fuel cap is venting properly, it does seem like there's a a possible fuel starvation problem going on hopefully the carb change might she'd some lite on things.

[Dirtygirty]

It's alive it breaths, farts and ring bing bings, at last swapping the carb Sorted it out took it for a run round town clocked up 13 miles ran quite well, it didn't break down put it that way, the jettings not far of but will need some adjusting.
Think I'll leave it as it is for now till I get a few more miles on the clock and things loosen up a bit, tick over is still a bit up and down and mid range 31/2 to 4k is a bit stuttery but when it hits 41/2k it wants to take off.
Just need to get a bit of mileage on it.

[Easy-X]

Nice! Do you think it would manage a trip to Box Hill or Newlands? Definitely get a lot of attention
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Dirtygirty]

Want get bit more mileage on first And maybe fit a new coil, looks like it's gonna get a few trips to Kingston hospital this week mums back in their, it's certainly seems to turn heads though! Id'e like to get the black red and white tank back on it, I think the red and white make a nice contrast to the black, it looks a bit daft Vader at the moment.
Didn't get a chance to ride it today hopefully tomorrow, if I can get some miles on it this week then I it would be nice to hit the hill the weekend, all depends if mum comes home the weekend wether I'm allowed to come out to play or not.