Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > Honda Tech

Honda Tech Honda Tech Forum - For Questions specific and of interest to Honda 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.

LinkBack Thread Tools Display Modes
Old 8 Sep 2003
Registered Users
HUBB regular
Join Date: Mar 2002
Location: holland
Posts: 79
XRV750: Adjusting the mixture/synchronisation: How?

Hi there,

I'm having a little trouble with mij AT. It runs very unregularly, and when I pull the choke it stops. Also the exhaust is black from the smoke, so it would seems to me that it's running too rich, and if I pul the choke it really chokes... My repair manual sais there's is a mixture adjusting screw on the carburators. I think I found it, but I'm not sure...

So does anyone know which screw to turn and in which way (right = leaner mixture?)

And does anyone know how to check the synchronisation of the carburators without the fancy workshop tools?

Reply With Quote
Old 9 Sep 2003
Contributing Member
Veteran HUBBer
Join Date: May 2001
Location: Central Portugal
Posts: 321
It's unusual for the mixture or the carb balance to need adjustment on an AT. This may sound daft, but have you checked the air cleaner. If it's clogged the mixture will be too rich.
\"Bon Chance\"
Reply With Quote
Old 10 Sep 2003
Registered Users
HUBB regular
Join Date: Apr 2001
Posts: 49
Check your choke cables as they can sometimes stick at the carb end. Take the tank off and remove the carb end of each cable which is only held on with a plastic nut. The choke plunger and spring is part of the cable and should be a certain distance out of the end of the cable (see manual for distance). This is why the choke cable has an adjuster halfway along it before it splits into two.

I've had my bike running rich on one cylinder because of a sticking choke but a quick squirt of WD40 on the plunger sorted it. The symptoms were one cylinder with sooty sparkplugs and uneven low speed running when warmed up, which got worse the longer you rode at low speed. Didn't seem to affect high speed running at all.

Reply With Quote
Old 17 Oct 2003
LordStig's Avatar
Registered Users
HUBB regular
Join Date: Oct 2003
Location: Fife, Scotland
Posts: 96
Yes, I've had the same problem on my transalp. It seems that with bikes that are left on the sidestand all the time (obviously not when they're being ridden) it's possible for water to find it's way into the cable for the front carb, even though the rubber sealing boot is in good condition. Eventually the cable, cable outer and spring corrode. Mine became so bad that the whole choke mechanism seized! Recently, I've started to have more problems and will be replacing the cable assembly.
Tall men see everyone else's bald patch but their own.......
Reply With Quote
Old 20 Oct 2003
mmaarten's Avatar
Gold Member
Veteran HUBBer
Join Date: Sep 2001
Location: in Samaipata, Boliva
Posts: 578
And here the easy way to check the carb. sync. in the field.

You need two pieces clear plastic fuel-line of about 2.5 meters.

Connect the end to the vacuum-outlet on the inlet-manifold and let the line's go up about 1 meter. attach them there to something (a tree?) and let the ends go down into a little bottle (or jerycan for all I care) with fuel so the ends are submerged.

Now start ther bike and you'll see something wonderfull hapening... the fuel get's "sucked" up into the line's and stay at a certain level... Ofcourse the levels must be the same... that's all there is to it.

One tip: Use fuel in the bottle... just in case it get's sucked in by the engine

Have fun


- www.maartensworld.com -
- Some photo's -
Reply With Quote

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


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!

Next HU Eventscalendar

See all events


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


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 00:22.