1996 Suzuki Intruder Backfiring and Poor Acceleration - Motorcycle-Journal Forums

buk · 08-31-2009, 07:42 AM

I have a 1996 Suzuki Intruder VS1400. When I first purchased by bike 3 years ago I let it sit for a year and had a bike shop clean the carbs. When I got it back it backfired upon deceleration. The bike shop told me that is what happens when the bike has after market pipes and that there was nothing else they could do.

The bike has after-market Cobra slash type of pipes.

About 8 months ago, while I was riding, I noticed gas pouring out the back side of my engine. Fortunately I wasn't too far from home and when I got home I noticed that the rear cylinder was cold. I figured that for something like that to happen all of a sudden it had to be an electrical problem. I followed the electrical troublehsooting guide in my Clymer's manual and found an open in a pick-up coil. At the time I did not have the proper equipment to do this work, mainly a motorcyle jack, since the bike needs to be lifted since the footpeg assembly which includes the kick stand needs to be removed to remove the side cases. Anyway the bike sat for 8 months until I purchased the equipment I needed and got the courage to attempt this type of repair. To make a long story short, after purchasing the pickup coil and removing the stator assembly, I found out that the coil was not open and that the troubleshooting wording was incorrect for my year of bike. I referenced the overall electrical schematic for my year of bike and found out that everything electrically on the bike was normal.

I then talked with more mechanically inclined friends and was told that a carb float could cause a sudden fault like I had with the gas pouring out the engine. After getting the bike back together I attempted to start the bike and gas once again poured out the rear of the engine. Then while another person started the bike, I tapped on the float to the rear carb and it started working. The bike idled better than it had ever done with out stalling. I thought that my problems were solved, but when I got out on the road, I found out that the bike was sluggish in acceleration and that I could not get over 50 mph while in 3rd gear. 4th gear, the cruising gear, was even worse. I thought that the carbs may just need cleaned out so I road a little more but nothing improved.

To summarize, the bike has been sitting for 8 months. The gas did turn bad in the tank during those 8 months so I drained the tank and filled with 93 Octane Shell gas. The engine still has the backfiring problem on deceleration but is now choppy in acceleration with a little pinging noises inside the engine while accelerating. With the accelerator fully pegged the bike basically cannot attain speed of more that 50 mph.

Any direction on a plan of action to follow in tracking down the problem would be appreciated.

Bob