1998 Timberwolf YFB250 4x2 backfiring issue at idle
#1
11-28-2016, 08:55 PM
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1998 Timberwolf YFB250 4x2 backfiring issue at idle
Hi everyone, I received a 98 Yamaha Timberwolf from my brother for free, and I'm working on getting it going.
I am having the following problem:
The engine is backfiring through the carb at idle.
I have done the following to try and get the four wheeler running:
Rebuilt the carb and set the air screw to 1-1/4 turn out and the circlip at middle position 3
Replaced the coil, because the cable was loose at the coil end
Repaired the main ground, coming from the battery
Replaced the ignition switch, because my brother couldn't find the key. New switch tested good
Tested the kill switch and it tested good
New coil tested goodfor both primary and secondary coils
Pickup coil resistance is at 195, which is correct
My source coil, is where I believe the issue is. The resistance is 310ohms, and it should be between 428-523ohms
When I opened the stator housing, there was significant oil, which I have read is normal. Does it sound like I'm on the right track replacing the source coil? Could this be causing my backfiring issue? It looks like the source coil is part of the stator assembly, is this correct? 4BD-85510-20-00 STATOR ASSY
I am having the following problem:
The engine is backfiring through the carb at idle.
I have done the following to try and get the four wheeler running:
Rebuilt the carb and set the air screw to 1-1/4 turn out and the circlip at middle position 3
Replaced the coil, because the cable was loose at the coil end
Repaired the main ground, coming from the battery
Replaced the ignition switch, because my brother couldn't find the key. New switch tested good
Tested the kill switch and it tested good
New coil tested goodfor both primary and secondary coils
Pickup coil resistance is at 195, which is correct
My source coil, is where I believe the issue is. The resistance is 310ohms, and it should be between 428-523ohms
When I opened the stator housing, there was significant oil, which I have read is normal. Does it sound like I'm on the right track replacing the source coil? Could this be causing my backfiring issue? It looks like the source coil is part of the stator assembly, is this correct? 4BD-85510-20-00 STATOR ASSY
Last edited by Derek Deuce Hall; 11-28-2016 at 08:58 PM. Reason: Added "backfiring issue at idle" to title
#2
11-29-2016, 11:06 AM
Have you pulled the spark plug after letting run for a few minutes and checking the condition? Backfiring through the carb could suggest a lean condition...does it improve if the choke is on? Were there any air filter mods done? I'd ensure it's not the carb before replacing electrical components. I'd also ensure the timing was on...