Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > Suzuki Tech
Suzuki Tech Suzuki Tech Forum - For Questions specific and of interest to Suzuki riders only.
Photo by Michael Jordan, enjoying a meal at sunset, Zangskar Valley, India

I haven't been everywhere...
but it's on my list!


Photo by Michael Jordan
enjoying a meal at sunset,
Zangskar Valley, India



Like Tree4Likes
  • 1 Post By Gipper
  • 1 Post By mollydog
  • 1 Post By DLyttle
  • 1 Post By Gipper

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 9 Dec 2013
Registered Users
HUBB regular
 
Join Date: Dec 2011
Location: Nelson NZ
Posts: 92
Dr650 carb adjustments at altitude

Has anyone had to change jets or make other adjustments when running at high altitudes on a DR650. What parts need to be carried please. Thanks
Reply With Quote
  #2  
Old 9 Dec 2013
Toyark's Avatar
-
Veteran HUBBer
 
Join Date: Apr 2006
Location: WWW
Posts: 2,341
Smile

It's all about jetting- a 2 second search with Google finds this PDF document with pics etc which you may find helpful until someone with more knowledge comes along.

Last edited by Bertrand; 7 Nov 2015 at 22:50.
Reply With Quote
  #3  
Old 9 Dec 2013
Gipper's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Mar 2004
Location: Saltspring Island,Canada/Poole,UK
Posts: 1,081
Hi DLyttle

Link from Bertrand is good info, but first lets start with a bit more information:
what year is your DR?
what mods have already been done to the bike?
what elevation (where) will you be riding it?

The stock jetting and fuelling is lean on the DR650, but the main issue for running at high altitude is the restrictive stock airbox setup, this can be modified very easily though!

If your DR650 is stock it will have a small 'snorkel' in the top of the airbox, this limits the amount of air getting to the carb.

Most DR650 riders will do 2 things, adjust the jetting/fuelling COMBINED with what is referred to as the 'Airbox Mod' which involves cutting out most of the top of the airbox.

You CANNOT do only one of these mods, they must be done together or you will end up running the engine way too lean (airbox mod only) or running way too rich (jetting carb only)

The best results are if you do both of these mods AND switch from the restrictive stock exhaust to a free flowing exhaust too.

These are solutions to make the DR650 run better - and better at altitude in ascending order of cost:

1) Depending on how high in altitude you intend to go, you could increase the fuel flow by removing the EPA blanking plug on the carb and fitting an extended fuel screw, increase the fuel flow and remove airbox snorkel. At very high altitude you may have to run the bike with the side cover off the airbox and make a slight adjustment to the fuel flow.
Cost $20

2) Jet the carb & do the 'airbox mod' as I mentioned, fit extended fuel screw.
Cost $80

3) Jet the carb, do 'airbox mod', fit extended fuel screw, fit a decent freeflowing exhaust.
Cost ~$400 - depending on exhaust system.

Which ever one you do, first thing to do is to fit a TwinAir filter!

There's also a few other tweaks that can be done to improve the throttle response too. we wont get into that yet!

A lot of guys also fit TM40 pumper carbs - which are $450 and still need the airbox mod and a decent exhaust too.

Pretty much all the information you need for the stock BST carb is here:

The BST-40 Bible - ADVrider

Here's MXRob's website too, he has done just about everything you can do to a DR650, including fuel injection!

http://www.mxrob.com/

Best BST40 jet kit IMO is Procycle's own kit, it has the extended fuel screw, drill bits to remove EPA blanking plug/drill slide, new jets and needle with clip slots and a 'D' spacer, which is much better than using washers as shims with the original needle. It also comes with hex cap bolts to replace the soft screws that the BST40 is held together with.

For any carb work I suggest removing the carb from the bike completely, it is quite quick to do and makes working on it much easier, it is a very simple carb and easy to work on.

My current set up is:
-extended fuel screw set at about 1.5 turns out
-Procycle needle, washer set at 4th clip from top.
-Slide drilled
-150 main jet
-airbox mod done
-Keintech mid pipe with GSXR 1000 Titanium exhaust and FMF USFS spark arrestor fitted
-TwinAir Filter

For all things DR650 look here:

http://www.procycle.us/bikepages/dr650.html

Hope that helps, let me know if you need any more info
__________________
Cheers
Grif

'11 KTM 450 EXC
'09 Suzuki DR650
'00 Discovery Series 2 V8
'95 Defender 90 300 Tdi Overlander
http://gipperstravels.blogspot.ca

Last edited by Gipper; 10 Dec 2013 at 03:21.
Reply With Quote
  #4  
Old 9 Dec 2013
mollydog's Avatar
R.I.P.
Veteran HUBBer
 
Join Date: Aug 2003
Location: california
Posts: 3,822
Good advice above.
A lot depends on how far "into" this you want to get. As mentioned, we need to know if your bike is currently stock or if it's been modified. There is lots you can do ... or you can do very little and still get by. Up to you. The DR650 is flexible!

If totally stock (means: no jetting changes, no washers under needle, no air box mods, snorkel still in place, stock exhaust). If the bike is running well then all you would need to do at very high altitude would be to install an Extended Fuel Screw. (AKA: Fuel/Air mixture screw or Pilot Screw). This is a 30 second adjustment once installed. So Easy. It is blanked OFF on stock Carb, so you'll need to learn how to get to this fuel screw. (not hard ... but, IMO, a MUST DO for travel)

As mentioned, stock DR650 is very lean. This means it can go up fairly high and still run pretty well. Over about 8K to 9K ft. it will lose some power and idle may drop down, may run a bit rough, harder to start. At this point remove snorkel and turn the extended fuel screw IN one half turn, this leans out the overly rich idle mixture a bit. This will help across the rev range, but especially at low RPM, idling and starting.

Then, raise idle up a bit. (1400 RPM is correct) Should run OK ... just remember ALL internal combustion engines lose power at high altitude, no matter the jetting, F.I. or Carb ... they ALL lose power. This adjustment will take you less than one minute to do.

Over about 12,000 ft. I would remove the air box side cover. (make sure to retain captive nuts/bolts) With cover off you should be OK up to 14,000 ft. and even higher. DO lean out Fuel screw further (another one quarter or half turn IN) and raise idle up again if needed.

Replace cover (five minutes to do) when down below 10,000 ft. again,
re-adjust fuel screw and idle once a lower altitude.

There are advantages and disadvantages to running a totally stock set up.
For LD adventure travel, leaving it all stock is not a bad thing. Your MPG will be good, your air filter will remain cleaner for longer and you can easily transition from Sea Level to 14,000 ft. with only minor adjustments that take just a few minutes at most.

Your DR will not have the "Punch" of modified DR's at Sea Level, but will run pretty well even at 13,000 ft. The guys with the modified Carbs and jetting won't be as lucky and will have to do more to get their bikes to run well at high altitude. (over 10,000 ft.)

Good luck!


Imogene Pass, over 13,000 ft. My modified DR ran like crap. Soon sorted however.
Reply With Quote
  #5  
Old 10 Dec 2013
Registered Users
HUBB regular
 
Join Date: Dec 2011
Location: Nelson NZ
Posts: 92
Thanks very good info. Bike is 2009 it's in New Zealand but going to Chile soon so I guess around 3000 m in Bolivia etc. it is completely standard. Just concerned that if I do too many mods fuel consumption will increase too much.
Reply With Quote
  #6  
Old 11 Dec 2013
Gipper's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Mar 2004
Location: Saltspring Island,Canada/Poole,UK
Posts: 1,081
our 2009 DR gets between 3.8-4.5 L/100km or 61-75 mpg (imperial gallons), if I keep it around 100 kmh it still gets 75 mpg, up at 110-120kmh down to 60 ish mpg.
That's with the modifications, they have not made a significant difference to fuel consumption, if you fit a TM40 pumper carb it will use more gas.

Highest elevation we got to was 4,800m at Jama pass, the bike ran pretty well, though obviously down on power that high.

It ran well until I got gas at San Pedro de Atacama that had a bunch of water in it

If you jet the DR and open the airbox it will run much better - especially for your trip, I wish I had done it earlier
__________________
Cheers
Grif

'11 KTM 450 EXC
'09 Suzuki DR650
'00 Discovery Series 2 V8
'95 Defender 90 300 Tdi Overlander
http://gipperstravels.blogspot.ca
Reply With Quote
  #7  
Old 11 Dec 2013
Registered Users
HUBB regular
 
Join Date: Dec 2011
Location: Nelson NZ
Posts: 92
Thanks Gipper for the first hand experience. Keep you posted. Rgds
Reply With Quote
  #8  
Old 12 Dec 2013
Gipper's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Mar 2004
Location: Saltspring Island,Canada/Poole,UK
Posts: 1,081
No worries, always good to help out

Mollydog makes some good points there and re side cover captive nuts, easy to lose them!

if you do not do the carb mod, you can also do what a buddy of mine did, which is to enlarge the snorkel hole in airbox and have a flap mounted on a single bolt to the side of hole, so that you can rotate the flap and cover/uncover a varying amount of the air intake, this with the extended fuel screw will give good easy adjustability at up to ~10,000 feet - as Mollydog mentions, as you get up high, if the bike is losing more power pull the side cover off and adjust fuel screw some more.

I wear pretty thin leather road gloves, so I can adjust the extended fuel screw on the move now - it takes a bit of practice but you have lots of time to do that going up the hills in Bolivia and Peru

I prefer the Procycle fuel screw which has the flat side on the screw head, much easier to make adjustments and know how many turns out the screw is.
__________________
Cheers
Grif

'11 KTM 450 EXC
'09 Suzuki DR650
'00 Discovery Series 2 V8
'95 Defender 90 300 Tdi Overlander
http://gipperstravels.blogspot.ca

Last edited by Gipper; 22 Oct 2015 at 00:12.
Reply With Quote
Reply

Tags
dr650, jetting dr650


Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
89 XT600 (kick start) Carb issue ajax Yamaha Tech 4 25 Oct 2013 18:02
For Sale: Seattle, WA USA 2009 DR650 bigalsmith101 TRAVEL Equipment for Sale / Wanted 0 18 Aug 2012 03:56
1988 PD06 Transalp carb jetting for altitude? chris Honda Tech 7 29 Apr 2012 20:46

 
 

Announcements

Thinking about traveling? Not sure about the whole thing? Watch the HU Achievable Dream Video Trailers and then get ALL the information you need to get inspired and learn how to travel anywhere in the world!

Have YOU ever wondered who has ridden around the world? We did too - and now here's the list of Circumnavigators!
Check it out now
, and add your information if we didn't find you.

Next HU Eventscalendar

HU Event and other updates on the HUBB Forum "Traveller's Advisories" thread.
ALL Dates subject to change.

2024:

2025:

  • Queensland is back! May 2-4 2025!

Add yourself to the Updates List for each event!

Questions about an event? Ask here

HUBBUK: info

See all event details

 
World's most listened to Adventure Motorbike Show!
Check the RAW segments; Grant, your HU host is on every month!
Episodes below to listen to while you, err, pretend to do something or other...

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

"Ultimate global guide for red-blooded bikers planning overseas exploration. Covers choice & preparation of best bike, shipping overseas, baggage design, riding techniques, travel health, visas, documentation, safety and useful addresses." Recommended. (Grant)



Ripcord Rescue Travel Insurance.

Ripcord Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers.

Led by special operations veterans, Stanford Medicine affiliated physicians, paramedics and other travel experts, Ripcord is perfect for adventure seekers, climbers, skiers, sports enthusiasts, hunters, international travelers, humanitarian efforts, expeditions and more.

Ripcord travel protection is now available for ALL nationalities, and travel is covered on motorcycles of all sizes!


 

What others say about HU...

"This site is the BIBLE for international bike travelers." Greg, Australia

"Thank you! The web site, The travels, The insight, The inspiration, Everything, just thanks." Colin, UK

"My friend and I are planning a trip from Singapore to England... We found (the HU) site invaluable as an aid to planning and have based a lot of our purchases (bikes, riding gear, etc.) on what we have learned from this site." Phil, Australia

"I for one always had an adventurous spirit, but you and Susan lit the fire for my trip and I'll be forever grateful for what you two do to inspire others to just do it." Brent, USA

"Your website is a mecca of valuable information and the (video) series is informative, entertaining, and inspiring!" Jennifer, Canada

"Your worldwide organisation and events are the Go To places to for all serious touring and aspiring touring bikers." Trevor, South Africa

"This is the answer to all my questions." Haydn, Australia

"Keep going the excellent work you are doing for Horizons Unlimited - I love it!" Thomas, Germany

Lots more comments here!



Five books by Graham Field!

Diaries of a compulsive traveller
by Graham Field
Book, eBook, Audiobook

"A compelling, honest, inspiring and entertaining writing style with a built-in feel-good factor" Get them NOW from the authors' website and Amazon.com, Amazon.ca, Amazon.co.uk.



Back Road Map Books and Backroad GPS Maps for all of Canada - a must have!

New to Horizons Unlimited?

New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!

Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80G/S.

Susan and Grant Johnson Read more about Grant & Susan's story

Membership - help keep us going!

Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events all over the world with the help of volunteers; we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.

You don't have to be a Member to come to an HU meeting, access the website, or ask questions on the HUBB. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.




All times are GMT +1. The time now is 00:45.