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Old 06-24-2012, 09:18 PM   #66346
Feelers
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Location: Anchorage, Alaska
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BST works for me

Quote:
Originally Posted by Snowy View Post
Who's using a properly jetted standard BST? Pretty sure I mentioned waaay back that it was "controversially modified".
I think I am. It runs well without any surging. It pulls hard when I give it throttle. Throttle response is just fine. It runs up to 100 mph. It's pretty smooth down to 7mph. It gets 56-58 mpg generally. It starts immediately without choke on warm days, and immediately with choke on colder days. It idles at 1400rpm. My temps are reasonable.
...And it pops on decel unless I hold the throttle open just a tiny bit.

Unfortunately, I don't know the specifics of slide drilling, and which needle is in it, and which clip the needle is on. I just swapped out the main jet when I bought it, and it worked great. I'll open it if anyone really cares.

My caveat: I haven't ridden a pumpered DR, so maybe I don't know what I'm missing, but I would spend $400 on suspension and other farkles long before I'd mess with the carb.

Secondly, I can't really understand the theoretical difference. They both meter fuel. The pumper's slide is throttle controlled and the BST's butterfly is throttle controlled. So the BST meters due to airflow due to butterfly position due to throttle position and the pumper meters due to airflow due to throttle position. Tomato tomatoe... The AP squirts a bit of fuel for a little better power burst when making large throttle movements. But for general riding, it's just metering for both. Knowing how the BST's fuel circuits work and overlap, I see no reason that you guys can't jet it properly. Jets are changeable. Needles are changeable (KTM, stock, Dynojet, European DR, Factory Pro). Needle height is adjustable. Fuel screw is adjustable. Pilot jet is changeable (though doesn't need to be changed). You can even drill the slide or stretch the spring for desired response.

There's my 2 cents.
Carry on!
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Old 06-24-2012, 09:32 PM   #66347
victor441
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Quote:
Originally Posted by Feelers View Post
I think I am. It runs well without any surging. It pulls hard when I give it throttle. Throttle response is just fine. It runs up to 100 mph. It's pretty smooth down to 7mph. It gets 56-58 mpg generally. It starts immediately without choke on warm days, and immediately with choke on colder days. It idles at 1400rpm. My temps are reasonable.
...And it pops on decel unless I hold the throttle open just a tiny bit.

Unfortunately, I don't know the specifics of slide drilling, and which needle is in it, and which clip the needle is on. I just swapped out the main jet when I bought it, and it worked great. I'll open it if anyone really cares.

My caveat: I haven't ridden a pumpered DR, so maybe I don't know what I'm missing, but I would spend $400 on suspension and other farkles long before I'd mess with the carb.

Secondly, I can't really understand the theoretical difference. They both meter fuel. The pumper's slide is throttle controlled and the BST's butterfly is throttle controlled. So the BST meters due to airflow due to butterfly position due to throttle position and the pumper meters due to airflow due to throttle position. Tomato tomatoe... The AP squirts a bit of fuel for a little better power burst when making large throttle movements. But for general riding, it's just metering for both. Knowing how the BST's fuel circuits work and overlap, I see no reason that you guys can't jet it properly. Jets are changeable. Needles are changeable (KTM, stock, Dynojet, European DR, Factory Pro). Needle height is adjustable. Fuel screw is adjustable. Pilot jet is changeable (though doesn't need to be changed). You can even drill the slide or stretch the spring for desired response.

There's my 2 cents.
Carry on!
Interesting! just bought my first DR650 this week and it has a Dynojeted BST on it and runs like yours, I have no complaints. The bike came with a used HS40 (Harley version of the TM40) pumper in a box and I've since learned it can be made to work in my Norton Commando so I may save it for that...but hopefully I'll get a chance to ride a DR with a well sorted TM40 so I can decide which bike to put the carb on
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Old 06-24-2012, 10:54 PM   #66348
Snowy
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BST/TM40 in a nutshell.

Throttle response is the primary advantage of a TM over the rejetted standard BST.

Throttle response is what the slide drilling and spring shortening give the BST. Thee was a thread somewhere on doing i, but I can't remember what it was called. DRJOE....something something....I took his mods and figured I'd go just a little further. If a bigger hole and less spring made better response, then 2 holes and even less spring would make more...yeah?

In a nutshell.


The extra fuel that the pumper squirts in when opening the throttle is achieved when the modified BST slide "snaps" open as the throttle is gradually opened. The slide will settle again under constant vacuum, but effectively what is being achieved is an over reaction in the slide. Getting it just right so it doesn't surge as the vacuum drops is the trick.

Because the BST uses a butterfly valve in front of the slide, this tends to even out the airflow.

The overall effect then, is for the BST to go slightly rich as the throttle is being opened.

Which is the same effect as the pumper with it's accelerator pump.

Once at constant throttle, the needle position and the main jet sizes determine the mixture. The slide settles under constant vacuum, and you get normal fuel metering via the transfer and main.


So in summary, lessening the throttle slide spring preload, and drilling the holes in the bottom of the slide will make the slide react faster. What is then achieved is an over reaction, a richening of the mixture, and a "pumper" like acceleration.

Side by side it's not quite as good as a pumper, but it's a hell of a lot better than a rejetted BST. You get the benefits of reasonable fuel consumption and reasonable performance for $0.

Which for me negated the need to buy a pumper. I had other priorities for the cash.

It took a lot of goes to get it right, it became one of those "make it work or else" projects. But it works.

Would I do it again or just buy a pumper? Well...I've made almost all the modifications to my 2nd DR, and it's running well. I'm thinking about a pumper simply because I've built everything else about this bike different to the first one I built.

There's no point making the same thing twice. I like to tinker.
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Old 06-24-2012, 11:01 PM   #66349
SkiBumBrian
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Quote:
Originally Posted by ADV8 View Post
This forum is more for the 1996 and on DR650 which was a major face lift year for the bike.
There is a forum here in Thumpers for that earlier DR who will know better but you could always consider the later bike.

http://www.advrider.com/forums/showthread.php?t=61568

.
Thanks!
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Old 06-24-2012, 11:59 PM   #66350
Snowy
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The BST40 bible

http://www.advrider.com/forums/showthread.php?t=347184


Knew it was here somewhere.

read the Carby Mods 101 section

This is referenced to the BST40 that was standard on the older KTM640 Adventures. Very similar carb to the DR.This was the source of some of my ideas, although I remember reading somewhere that only drilling out the existing hole in the slide was recommended.

Can't find reference to that on initial inspection.

I went crazy on the spring shortening. Then stretched the spring a couple of times to get to "no surging" condition.

Essentially, with the way springs work, by shortening the spring (cutting off coils) you are lessening the preload and slightly increasing the spring rate. Edit: this is true if the spring is the same size wire, same size coil - or straight rate. Reducing the number of coils lessens preload, while the remaining spring gets slightly stiffer in rate overall. Getting the right preload/spring rat is the key to this mod. So stretching the spring to correct for cutting off too many coils will very slightly increase it's overall rate - but not by much. The preload on the spring is the most crucial aspect here less preload means the slide opens at less vacuum differential...essentially it's compensation for making the holes in the slide bigger

Some people didn't bother, he covers that in the thread, and there's references to other threads where similar arguments to what has played out here played out.

Lots of people contributing ideas, lots of people on the side lines screeching and throwing poo. It's called the internet.

Enjoy.

Snowy screwed with this post 06-25-2012 at 12:11 AM
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Old 06-25-2012, 04:07 AM   #66351
dljocky
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Valve Checks

My last valve check was over 4700 miles ago. I'm leaving this afternoon for a trip. 1300 miles total. The valve check totally slipped my mind. Any thoughts on whether this would be alright, or should I postpone it? 2009 DR650 with 33,000 miles.
Thanks all.
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Old 06-25-2012, 04:52 AM   #66352
koh kood
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Rear Sprocket 46 tooth

I've searched but have been unable to find a 46 tooth steel rear sprocket for the stock size 525 chain, 2003 DR 650. Any suggestions? I don't want to use a 14 tooth front sprocket or an aluminum rear sprocket.
Thank's
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Old 06-25-2012, 05:32 AM   #66353
Snowy
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Quote:
Originally Posted by dljocky View Post
My last valve check was over 4700 miles ago. I'm leaving this afternoon for a trip. 1300 miles total. The valve check totally slipped my mind. Any thoughts on whether this would be alright, or should I postpone it? 2009 DR650 with 33,000 miles.
Thanks all.
Is there valve clearance noise?

Have you had to make adjustments regularly, or do you just check and confirm?

If there's no noise, or they have had to have regular adjustment then maybe you should have a quick peek in there.

Mine have been fine for nearly 40,000km. No adjustments. Just occasional checks.

But I've run high concentrations of Molybdenum, 10-70 full synthetic oil, and heavy duty oil stabiliser since near new. If they needed adjustment I'd be curious as to why. According to the claims made by the manufacturers I should get about a quadrillion km on this engine before rebuild.***


***claims may not be factual.
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Old 06-25-2012, 06:03 AM   #66354
Albie
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Quote:
Originally Posted by Feelers View Post
I'd also like to see the difference between my bike and a KTM 690, TE 630, and BMW 650 if anyone is willing. I'm mostly curious about engine performance right now, so I'd only really want a road test, so I won't hurt anyone's bike!
Just thought I'd ask.
Oh, you really, really, really don't want to do that, the DR is what it is, but you start comparing it to the 690 or 630 you're gonna hate it.
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Old 06-25-2012, 06:05 AM   #66355
JoshB
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Pics from this weekends ride

Rode up georgia pass and webster pass this weekend.

Top of Webster pass /\/\/\


top of geogria pass and the continental divide.
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Old 06-25-2012, 06:07 AM   #66356
Albie
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Quote:
Originally Posted by GaThumper View Post
I thought I had read that the Freeride WOULD be street legal, but I guess we won't know for SURE until it shows up here, hopefully next year. And while the power is down at 24hp, with a weight of 220 it could be enough and hopefully the detuned 350cc motor has good power at lower RPMs and a nice wide power band! I'll bet there will be ways to get a little more power out if it too, since it's essentially a detuned makeover of the 45+ horsepower 350 exc-f.
The Freeride is not what a lot of people seem to think it's going to be. It's an Enduro/Trials hybrid. It is not meant to be a competitor to the WR 250R as a dual sport.
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Old 06-25-2012, 06:13 AM   #66357
Motodeficient
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Quote:
Originally Posted by Snowy View Post


52.3MPG 22.5km/l average.


.

Congrats, after all that you still get the same or less mileage than most people, including myself, got with the recommended Dynojet settings. And yes, it also ran good. I didn't even notice much of a difference when I switched to a pumper carb.
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Old 06-25-2012, 07:10 AM   #66358
shu
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Quote:
Originally Posted by dljocky View Post
My last valve check was over 4700 miles ago. I'm leaving this afternoon for a trip. 1300 miles total. The valve check totally slipped my mind. Any thoughts on whether this would be alright, or should I postpone it? 2009 DR650 with 33,000 miles.
Thanks all.
Regular Suzuki maintenance schedule for checking valves is every 7500 miles. You will only be at 6,000 miles when you return. Plus, if your bike is like mine, the valves are pretty stable anyway. (My bike has 45,000 miles on it, and I haven't had to touch the valves since I checked them at 7500 miles.)

Ride and don't worry about it.

.................shu
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Old 06-25-2012, 07:14 AM   #66359
Spud2836
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Eek

Quote:
Originally Posted by BergDonk View Post
Yeah, the last one is replacing a cush drive bearing on the banks of the Darling at Wilcannia while we had lunch.

The bike was recently new to the rider, and it was his first big trip. I checked all the cush bearings most days, but forgot the night before, so while the puncture was being fixed on the other DR, I checked them again. 600 kms since checked, and about 2-3 mm lateral movement of the sprocket had developed in that time. Changed it 50 kms later on a nice concrete footpath. It was a double sealed All Balls or Moose, the ones with blue seals with no markings, and had seen some water, and no extra grease had been added. I doubt any bearing would have done much better. The wheel bearings weren't great either, so while it was out, did them too.

The pic before was a different bike a couple of hours before when the rider kept riding with a flat E09 Dakar, the stiff sidewall one. The tube was spirally shredded and beyond repair. The tyre wasn't great either, with noticable sidewall damage internally. It was also a major pain to break the bead due to the heat and it welding itself to the rim. Just found these pics FYI, seen a tube like this before?



Biggest fuel range needed on this trip was Arkaroola to Cameron Corner, about 420 kms.

Here's a couple more:



Steve

Nice photos, almost made me homesick. I was born and raised in Wilcannia. Family and friends still their. I did say almost homesick.
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Old 06-25-2012, 07:36 AM   #66360
Snowy
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Quote:
Originally Posted by Motodeficient View Post
Congrats, after all that you still get the same or less mileage than most people, including myself, got with the recommended Dynojet settings. And yes, it also ran good. I didn't even notice much of a difference when I switched to a pumper carb.
Ah, ok. So everyone else is wrong and you are the only one that's right. That's what you're saying here.


talking to you guys about DRs is like talking Ice Hockey with a Canadian who can't skate....eh!
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