backfiring 2000 SX700R

yamyrider

yamyrider

Active member
Joined
Nov 6, 2003
Messages
1,598
Age
56
Location
Northern Ontario
HI. I have just completed reed spacers, removed two layers of head gasket, installed bender silencer and clutching.
I started the machine and when I push the throttle it backfires and taked longer for the idle speed to come down to normal idle. When it does reach normal idle it seems to run fine. WHAT IS GOING ON. It was running fine before the mods.
 
sxr

It hard to say without hearing it, but my first guess would be that you have one of the boots from the air box that is not sealed properly(or other air leak) I had my machine set up the same, and did not experience the high idle. I did run into back firing if I didn;t let the motor heat up properly before getting into the gas. (you didnt adjust the carbs in any way right??, and none of the cables are routed improperly)

Again, mine was VERY cold blooded, and I had to be sure it was warmed up.

Good luck

John
 
backfiring 2000 sx700r

Sounds lean, when you are running flip first notch of choke if it takes the throttle and runs good you know you are lean. adj air screws or go one richer pilots, with what you have done should go richer pilot , could also have gasket leaking on reed spacers
 
Thanks Guys,
So far I have not made any fuel or air adjusments and I left stock jetting.
To explain the problem a little better....when I first start the machine it idles ok, let it warm up a minute or more then give it a little gas, it will then backfire and when I release the throttle at that point at takes a long time for the idle to lower to normal idle speed. It stays high at about 2500 RPM for about 40 seconds then slowly starts to come down.
 
sxr issues

Ok - try this:
Start sled, and get the idle to jump to that 2500: Rather than wait 40 seconds--hit the choke, and see if this drops the idle down. If so you have a lean condition due to carb setting, or my original guess of an air leak (? at the boot air box connection, probably at the center carb)

If not - pull the carbs, check all adjustments (including pilot screw) and reinstall--This will be the safest way, and will be a check for boot carb connection. Trust me when I tell you often the boots look connected, but they are not.

I will not check back here, but if you have a specific question PM me.
Be sure to blow out carbs when(not if) you take tham back off.

Good luck,

John

WNY
 
You must log in or register to reply here.


Back
Top