Question about 1989 Suzuki Rg 400
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
as you have replaced carbs you will need to retune for fuel intake also check its getting enough air ie.. air filter has been changed or is clogged
Posted on Jun 17, 2009
You need to fix the fueling first - without fuel it won't run!
Your other problem sounds like an air leak - either the manifold or the carb. Check by spraying WD-40 or CRC at the manifold and carb join while the bike is running - if the revs change (either up or down) you have a leak.
Posted on Jun 29, 2009
Lean mixtures burn very slowly, at times slowly enough to continue
burning through the power and exhaust stroke, causing a backfire when
the intake valve opens, and that flame gets a shot at the new mixture
In normal operation, as the engine slows, the fuel delivery from the main circuit falls off, and the idle circuit is supposed to take over. If the idle circuit flows insufficiently, that becomes a transition to fuel starvation.
You can try pointing an unlit propane torch into the inlet air, and see if you can get closer to an idle while supplying a supplementary fuel source. You will need to do this in a way that gets propane to both carburetor inlets, maybe rigging a Y with vacuum hoses and electrical tape...
This started with work on the carburetors, so the fuel system would be the most suspect. That, and the fact that it will run at higher RPM would seem to rule out fuel delivery.
I was looking around at photos while developing this answer (needed to know whether this was a twin or a 4-cylinder), and one resource said the idle speed should be 1,200. I don't know if that's right, but maybe 1,000 RPM is too slow for this motor to keep it together. (I do doubt that, though.)
When I wrote that last sentence, I started to second guess myself, thinking "What if the fuel shutoff(s) is/are vacuum operated, and as the bike approaches idle there is insufficient vacuum to hold it/them open?" But the I rejected that, because there is even less vacuum at cranking speeds, yet the bike starts.
Posted on Jun 26, 2010
Tips for a great answer:
Oct 22, 2016 | Malaguti Motorcycles
Jan 22, 2014 | 2012 Yamaha Zuma 50F
May 18, 2013 | Aprilia Pegaso 650 Motorcycles
Feb 17, 2012 | 2010 Malaguti Grizzly 12 Enduro
Jul 03, 2011 | 2006 Derbi Atlantis Bullet
Dec 15, 2010 | Husqvarna , No.455 Rancher, 20" Gas -...
Sep 26, 2010 | 2005 Harley Davidson FLHTC - FLHTCI...
May 28, 2010 | Harley Davidson Harley-Davidson Motorcycle...
Feb 15, 2010 | 2008 Yamaha Yamaha G5
64 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: