I have a 1985 FXRS. It was purchased brand new in 85. Due to some work issues it ended up sitting in the garage for a few years. Recently I worked on getting it running again. I was able to get it running and ride it. After a few rides it started to backfire through the carburetor. Since I had not removed the carb to clean it before I got it running I now removed the carb, cleaned and rebuilt it, replaced the intake manifold gaskets and put it all back together. On Tuesday I was able to get it started. It started easily and ran fine at idle. On my test ride it rode like a "bucking bronco", that is to say it would run fine then not and require gas to keep it running then had to back off, etc. I then put it back in the garage. Today I removed the air cleaner to ensure there were no obstructions of either air or gas flow. I left the air cleaner off and the bike started right away and idles at 1000 rpm. When I pushed the choke in (probably a little too early) I had trouble keeping it from stalling at idle. I then tried to start it again and click, click, click. The click is coming from the bosch relay on the right side next to the computer module. I thought maybe the battery was bad and I hooked up a charger, no change. I removed the connections, cleaned them, put contact lube on them, reconnected and tried again. No change. I stopped and put the bike back on the battery tender. Once the battery tender indicated that the battery was charged I tried again, no success. I'm looking for things to check. I'm considering removing the battery from a good running bike and replacing the one on the 85 FXRS to see if the problem goes away. Any ideas would be appreciated.

LDR (Long Distance Rider)

 

switch the relays if cranks over then it's the relay

 

Did you turn on the petcock ? Lol I have one carbureted bike and I sometimes forget to do so 😂

 

Any sediment in your gas tank?

 

Thanks. I switched out the relay and it started. Now to fix my backfiring problem.

 

No problem. I'm used to petcocks.

 

I have plenty of gas flowing in both normal and reserve position. My main issue now if backfiring through the carb at load.

 

I'm now tracking down the cause for backfiring through the carb. I have plenty of gas flowing from the tank in both the normal and reserve position. The carb was just rebuilt. The intake manifold gaskets were replaced. Only way I could keep the bike running somewhat normal while riding was with the choke partially closed. With the choke fully open the bike seems to lose power and requires a lot of throttle which makes it buck a little. From everything I have read it seems that there is either an air leak or a blocked gas passage.

 

When I replaced my rubber fuel line on my 92 fxr I cut it a little bit longer than the stock length. It was just enough to obstruct gravity flow. Went down the road and she started to back fire. Worth checking. It idled fine but when I got on it back fired. If not check intake for leaks, warped intakeflanges are vey common problem on thease bikes.

 

Thanks. I did not replace the fuel line and I checked flow through it albeit into a gas container. I will keep that in mind. I'm going to remove the carb again and go in and check the intake manifold. It is a challenge since you can not get in there with a tool to torque the bolts. I had to purchase a special wrench just to get access. I tried a number of combinations of sockets, u-joints and extensions with no luck. I don't want to bring the bike to a dealership for two reasons 1) cost and 2) distance (over 60 miles).