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. Questions comparing which bike is best etc go in the "Which Bike" forum.
Contact Overland Solutions for all your custom modifications and setup for overland travel.

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 22 Apr 2008
Gold Member
HUBB regular
 
Join Date: Jul 2007
Location: Oregon, US
Posts: 25
DR250 at altitude

Hey Everybody.

My girlfriend and I just road from Argentina to San Pedro de Atacama in Chile and her DR250 was running so bad by the end of the pass that I actually had to push it up some of the hills. The thing is it ran fine up to 4100 meters and then it started to miss and sputter. By the end I could hardly keep it running and only in the lower gears and high RPMs. We removed the air filter but it only helped a small amount. Now that we are lower 2500 meters it is runing fine. We intend to go to Bolivia and I want to make the proper adjustments to avoid this problem again. I am thinking about a different jet if I can find one and I donĀ“t know how to adjust the air screw because it is seeled which I am thinking about breaking the seel. Any advice would be great.

Brad
__________________
www.motorcyclegypsy.com
Reply With Quote
  #2  
Old 22 Apr 2008
Nigel Marx's Avatar
Super Moderator
Veteran HUBBer
 
Join Date: Oct 2000
Location: South Island, New Zealand
Posts: 755
Thumbs up

Hi Brad. Doesn't sound like much fun. The air screw adjusts the amount of air bleeding into the riser for the main jet, turning the fuel going up toward the carb throat into a foam. This makes it vaporise more effectively and mix better. Letting more air in will lean the mix up a little, but it's not as good as putting in a smaller main jet. If you can break the seal, turn the air screw carefully inwards COUNTING HOW MANY TURNS until it's gently seated. It's usually something like 1.5 turns. You need to know so you can re-set it. Then back it out to where is was and then try another half turn further out. I would guess that any more than 1 complete turn out from normal would be the most that will still let the motor run OK.

Have you been into a carb before? If not I'm sure there are lots of pictorial guides on the net. It's easy to replace a main jet. They are usually either the sort that are buried inside the riser and you need a correctly sized, well fitting screw-driver to get them out, or are the more external hex-headed sort that you need a 6mm (about) spanner to undo. There will be a number on it, something like 122.5 or 140 etc (the numbers on most carbs go up in 2.5 increments). Find what number is on your mainjet and buy the next two sizes down. IT"S A BAD THING TO USE TOO SMALL A MAIN JET FOR THE CONDITIONS! You can over-heat and seize the engine running too lean for too long. Fuel going into the motor and vaporising has a big impact on the internal cooling, especially to the piston. Try one size smaller before deciding on going two sizes smaller. It's a bit hit and miss, but that's how it is with carbs. Be very sure to replace the original main jet as soon as you get to lower altitudes. If you know that you are going to head up again and don't want to keep replacing the main jet all the time, it's OK to run with a smaller main for a while as long as you keep the throttle at less than 60%. The restriction of the main jet size on fueling doesn't come into play until you are getting close to wide open.

Hope this helps.

Kind regards

Nigel in NZ
__________________
The mouth of a perfectly contented man is filled with . -- 2200 BC Egyptian inscription
Reply With Quote
  #3  
Old 23 Apr 2008
Contributing Member
Veteran HUBBer
 
Join Date: Jul 2002
Location: Sydney, NSW, Australia
Posts: 1,366
Yes - remove the plug that covers the air screw. If it is like the 650 then instructions exist on how to remove it on the web. It only changes things at low throttle settings ..

You will need to get teh smaller main jets - 1 one size smaller 1 two sizes smaller .. the standard size will be in a manula somewhere .. or in the parts list. Jets should be about $10 each..
__________________
---
Regards Frank Warner
motorcycles BMW R80 G/S 1981, BMW K11LT 1993, BMW K75 G/S
Reply With Quote
  #4  
Old 25 Apr 2008
Gold Member
HUBB regular
 
Join Date: Jul 2007
Location: Oregon, US
Posts: 25
on going problems

Hey Guys

thanks for the advise. I did take the carb out and found it was full of crap so I gave it a good cleaning and then proptly broke the little plastic piece on the side. Which I found a replacement for in Calama which they charged me 45 dollars for. So today I put it all back together and adjusted the air screw but could only make it to 3600 meters no matter how I turned it. The only jet I could find in Calama was a 108 and I am running a 115 so I was not sure if is was to small. So I ran a wire in the jet and made it to 4200 meters but it does not have any power at 4200 so I think I will return to Calama and look for more jets. The question I have is what size would be two steps down from 115.

Thanks Brad
__________________
www.motorcyclegypsy.com
Reply With Quote
  #5  
Old 25 Apr 2008
Registered Users
Veteran HUBBer
 
Join Date: Sep 2007
Location: Saudi Arabia
Posts: 178
I don't know if your carb has a throttle needle with notches on.
I used to be at 9,000 ft at my last base and the bikes we had all ran rough until we dropped the needles down to the last notch which had the effect of weekening the mixture. We also did this on our motocrossers for raceing but you have to do it all again when you come down to sea level.
Ducati 600 monsters,CR 250,RM 250,CR500 etc.
Cheers
Ian
Reply With Quote
  #6  
Old 25 Apr 2008
Gold Member
HUBB regular
 
Join Date: Jul 2007
Location: Oregon, US
Posts: 25
I think you can read my mind

I was just trying to figure out if dropping the needle down would help. Right now it is on the thrid notch and it seems to me if I put it on the 1st notch it would push the needle into the jet farther and restrict flow. Is this correct?

Thanks Brad
__________________
www.motorcyclegypsy.com
Reply With Quote
  #7  
Old 25 Apr 2008
Registered Users
Veteran HUBBer
 
Join Date: Sep 2007
Location: Saudi Arabia
Posts: 178
Yes.
There should be four or five notches, we put the little circlip in the top notch which lets the needle drop lower into the jet. This made our bikes run better but not perfect.
We lived at 7,000 ft and rode up to 9,000 ft and down to sea level which didn't effect the bikes too much but when we raced at sea level we reset the needles.
Good Luck with yours.
Ian
Reply With Quote
  #8  
Old 29 Apr 2008
Gold Member
HUBB regular
 
Join Date: Jul 2007
Location: Oregon, US
Posts: 25
Thank you!

Well we finally managed to get the bike to the Titio Gysers at 4,300m with a 110 jet and a wire. We also moved it up two notches.
Thank you!
We{ve been also having problems with the bike not starting in the morning, but maybe the battery is just dead....guess we{ll see if we can get a new one in Bolivia.
thanks again..
__________________
www.motorcyclegypsy.com
Reply With Quote
  #9  
Old 29 Apr 2008
Nigel Marx's Avatar
Super Moderator
Veteran HUBBer
 
Join Date: Oct 2000
Location: South Island, New Zealand
Posts: 755
Air Screw??

If the air screw is out a little too far, that will make it difficult to start. If you have turned it out, try putting it back in a bit until the motor is warm.

Regards

Nigel in NZ
__________________
The mouth of a perfectly contented man is filled with . -- 2200 BC Egyptian inscription
Reply With Quote
Reply


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
Suzuki DR250 in Santiago AJ TRAVEL Bikes for Sale / Wanted 1 17 Jul 2008 10:56
altitude jpmottais TRAVEL Hints and Tips 1 31 Mar 2007 12:26
Luggage on DR250 38thfoot Equipping the Bike - what's the best gear? 1 11 Jan 2006 18:05
DR250/ TS185 Q's TS Boy Suzuki Tech 0 27 May 2005 18:32
Dommie at altitude Oz Honda Tech 3 15 Oct 2004 11:34

 
 
 

NEW! HU 2015 Motorcycle Adventure Travel Calendar is now available! Get your copy now for some terrific travel inspiration!

HUGE, 11.5 x 16.5 inches, beautifully printed in Germany on top quality stock! Photos are the winning images from over 600 entries in the 9th Annual HU Photo Contest!

Horizons Unlimited 2015 Motorcycle Adventure Travel Calendar.

"The calendar is magnificent!"

"I just wanted to say how much I'm loving the new, larger calendar!"

We share the profit with the winning photographers. YOU could be in the HU Calendar too - enter here!


HU DVD Autumn Special!

Take 40% off Road Heroes Part 1 until October 31 only!

Road Heroes features tales of adventure, joy and sheer terror by veteran travellers Peter and Kay Forwood (193 countries two-up on a Harley); Dr. Greg Frazier (5 times RTW); Tiffany Coates (RTW solo female); and Rene Cormier (University of Gravel Roads).

The first in an exciting new series, Road Heroes features tales of adventure, joy and sheer terror by veteran travellers."Inspiring and hilarious!"

"I loved watching this DVD!"

"Lots of amazing stories and even more amazing photographs, it's great fun and very inspirational."

"Wonderful entertainment!"

Check it out at the HU Store! Remember to use Coupon Code 'HEROES' on your order when you checkout.



Scottoiler automatic chain oilers. The most important accessory for your next motorcycle adventure!


Renedian Adventures


Renedian Adventures

What others say about HU...

"I just wanted to say thanks for doing this and sharing so much with the rest of us." Dave, USA

"Your website is a mecca of valuable information and the DVD series is informative, entertaining, and inspiring! The new look of the website is very impressive, updated and catchy. Thank you so very much!" Jennifer, Canada

"...Great site. Keep up the good work." Murray and Carmen, Australia

"We just finished a 7 month 22,000+ mile scouting trip from Alaska to the bottom of Chile and I can't tell you how many times we referred to your site for help. From how to adjust your valves, to where to stay in the back country of Peru. Horizons Unlimited was a key player in our success. Motorcycle enthusiasts from around the world are in debt to your services." Alaska Riders

contest pic

10th Annual HU Travellers Photo Contest is on now! This is an opportunity for YOU to show us your best photos and win prizes!

NEW! HU 2014 Adventure Travel T-shirts! are now available in several colors! Be the first kid on your block to have them! New lower prices on synths!

HU 2014 T-shirts now in!

Check out the new Gildan Performance cotton-feel t-shirt - 100% poly, feels like soft cotton!


What turns you on to motorcycle travel?


Global Rescue, WORLDwide evacuation services for EVERYONE

Global Rescue is the premier provider of medical, security and evacuation services worldwide and is the only company that will come to you, wherever you are, and evacuate you to your home hospital of choice. Additionally, Global Rescue places no restrictions on country of citizenship - all nationalities are eligible to sign-up!


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 R80 G/S motorcycle.

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 (22 this year!); 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, the HUBB or to receive the e-zine. 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.


Books & DVDs

amazon

All the best travel books and videos listed and often reviewed on HU's famous Books page. Check it out and get great travel books from all over the world.


Motorcycle Express for shipping and insurance!

Motorcycle Express

MC Air Shipping, (uncrated) USA / Canada / Europe and other areas. Be sure to say "Horizons Unlimited" to get your $25 discount on Shipping!
Insurance - see: For foreigners traveling in US and Canada and for Americans and Canadians traveling in other countries, then mail it to MC Express and get your HU $15 discount!




All times are GMT +1. The time now is 13:03.