Backfiring

[00Vs1400GLP]

Coming to you all once again before I resolve to taking the carbs off of my bike for the second time since I’ve owned it. Occasionally when I ride, as I shut the engine down I get a backfire from both exhaust pipes. Is there an adjustment somewhere that might be off that I can look into before I pull the carbs and make sure they’re clean and verify the float heights? Maybe out of synch? Let me know what you got. My understanding of backfires is excess fuel in the tail pipe igniting so I was thinking of looking over spark plugs and coils etc to make sure I’m getting spark and a complete burn in the cylinders. How far off base am I?

[Herb]

When Mine did that it was a lean idle jet setting.

If you have had the carbs off did you remove the covers over the idle jet screw?

[00Vs1400GLP]

When Mine did that it was a lean idle jet setting.

If you have had the carbs off did you remove the covers over the idle jet screw?

Is that the screw the factory says you’re not supposed to touch?

[Herb]

When Mine did that it was a lean idle jet setting.

If you have had the carbs off did you remove the covers over the idle jet screw?

Is that the screw the factory says you’re not supposed to touch?

yep. One of the problems with it is that it has an o-ring on it and if you run carp cleaner through the idle air jet it can destroy the o-ring. Another problem with it is the factory settings are too lean which will cause a popping in the exhaust.

If I remember correctly my bikes came with about 1 3/4 turns out from stop. I pulled the cover off and ran them out to 2 1/4 turns out and they both ran much better, without any popping.

[Designer]

Coming to you all once again before I resolve to taking the carbs off of my bike for the second time since I’ve owned it. Occasionally when I ride, as I shut the engine down I get a backfire from both exhaust pipes. Is there an adjustment somewhere that might be off that I can look into before I pull the carbs and make sure they’re clean and verify the float heights?

Could you tell us what you did when you had them off before?

I ask to see if that information will confirm the sound advice that Herb has given you.

[00Vs1400GLP]

Coming to you all once again before I resolve to taking the carbs off of my bike for the second time since I’ve owned it. Occasionally when I ride, as I shut the engine down I get a backfire from both exhaust pipes. Is there an adjustment somewhere that might be off that I can look into before I pull the carbs and make sure they’re clean and verify the float heights?

Could you tell us what you did when you had them off before?

I ask to see if that information will confirm the sound advice that Herb has given you.

I took them off before because about 4 years ago the air filter disintegrated and the foam made its way into the carbs. I cleaned all of that out. I had them completely broken down except for the idle air screw. The reason I didn’t take them out is because at least one of them is seized. It ran fine after I cleaned/synched them. That was before the bike sat for a few years though. I might have to attempt to get that screw free again.

[hillsy]

That was before the bike sat for a few years though. I might have to attempt to get that screw free again.

Yes - you would be best to get the screws out and clean the passageways.

[Designer]

Coming to you all once again before I resolve to taking the carbs off of my bike for the second time since I’ve owned it. Occasionally when I ride, as I shut the engine down I get a backfire from both exhaust pipes. Is there an adjustment somewhere that might be off that I can look into before I pull the carbs and make sure they’re clean and verify the float heights?

Could you tell us what you did when you had them off before?
I ask to see if that information will confirm the sound advice that Herb has given you.

I took them off before because about 4 years ago the air filter disintegrated and the foam made its way into the carbs. I cleaned all of that out. I had them completely broken down except for the idle air screw. The reason I didn’t take them out is because at least one of them is seized. It ran fine after I cleaned/synched them. That was before the bike sat for a few years though. I might have to attempt to get that screw free again.

Interesting that when you completely cleaned them 4 years ago, it ran fine even though you didn't remove the Idle Screws.

But now that it has sat for two years, it's best you remove them both and check the O ring seals as Herb suggests.

About the best over-the-counter penetrating oil I know of is PBlaster. Much better than Liquid Wrench for sure.

I'd let the Chemicals do the work for you,...spraying it about twice a day for about two days

[00Vs1400GLP]

Thanks for the input. Looks like the carbs will be coming off again when I find the time. I tried the PBblaster last time and had no luck. I guess I’ll have to get the drill and extractor set out. Didn’t do that last time because I was worried about damaging the carb body. Luckily the new screws are readily available on eBay. I’ll probably just get carb rebuild kits and refresh everything else again so I can ensure I don’t have to pull these things off again anytime soon.

[Herb]

You might try spraying the PB Blaster in the idle air jet or remove the jet and spray it in the passage.

[Designer]

Thanks for the input. Looks like the carbs will be coming off again when I find the time. I tried the PBblaster last time and had no luck. I guess I’ll have to get the drill and extractor set out. Didn’t do that last time because I was worried about damaging the carb body. Luckily the new screws are readily available on eBay. I’ll probably just get carb rebuild kits and refresh everything else again so I can ensure I don’t have to pull these things off again anytime soon.

You speak of using the Drill/Extractor method,... Are you saying the Head is stripped on the Idle Screw?

Given the super small Diameter of the Idle Screw, and that it is a Slotted Head, I would like to recommend you re-think doing that.

I see this method as very easily going very wrong. For an Extractor to work, it has to be centered in the Idle Screw. And when I look at the very small Diameter and that it is not a Phillips head, I can see how the Drill is most likely to walk off-center and into the Aluminum Carb Body,...causing all sorts of irreparable damage.

When you used PBlaster, how long did you let it work? And did you do what Herb suggested and spray into the other end,...closer to the Threads?

I'd hate to hear you need a New Carb

[00Vs1400GLP]

Thanks for the input. Looks like the carbs will be coming off again when I find the time. I tried the PBblaster last time and had no luck. I guess I’ll have to get the drill and extractor set out. Didn’t do that last time because I was worried about damaging the carb body. Luckily the new screws are readily available on eBay. I’ll probably just get carb rebuild kits and refresh everything else again so I can ensure I don’t have to pull these things off again anytime soon.

You speak of using the Drill/Extractor method,... Are you saying the Head is stripped on the Idle Screw?

Given the super small Diameter of the Idle Screw, and that it is a Slotted Head, I would like to recommend you re-think doing that.

I see this method as very easily going very wrong. For an Extractor to work, it has to be centered in the Idle Screw. And when I look at the very small Diameter and that it is not a Phillips head, I can see how the Drill is most likely to walk off-center and into the Aluminum Carb Body,...causing all sorts of irreparable damage.

When you used PBlaster, how long did you let it work? And did you do what Herb suggested and spray into the other end,...closer to the Threads?

I'd hate to hear you need a New Carb

I tried the blaster over the course of a week that I had the carbs off last time. Still started to damage the screw head. I have used extractors a lot since then though so my confidence in being able to do it without causing damage to the body is higher and it will be a used last resort. If the screw head gets much more damage I won’t have a choice though.

[hillsy]

Good luck with getting the screw out - you need to get it out to clean the circuit properly.

Just so you know - PB Blaster in through the air jet won't get anywhere near the threads on the screw.

[00Vs1400GLP]

Good luck with getting the screw out - you need to get it out to clean the circuit properly.

Just so you know - PB Blaster in through the air jet won't get anywhere near the threads on the screw.

Thanks. Just in case, since carburetors are basically unobtanium, is there any possibility of doing a fuel injection conversion? . I’m kidding, I’m sure it’ll be fine.

[Designer]

Good luck with getting the screw out - you need to get it out to clean the circuit properly.
Just so you know - PB Blaster in through the air jet won't get anywhere near the threads on the screw.

Thanks. Just in case, since carburetors are basically unobtanium, is there any possibility of doing a fuel injection conversion? . I’m kidding, I’m sure it’ll be fine.

There is a fuel injection upgrade available. I don't know it's price, but I'll wager it's much higher than you want to know.


Oh,.....one more thing,.......there is a way that PBlaster can get to the Idle Screw Threads via the Pilot Jets.

[hillsy]

Oh,.....one more thing,.......there is a way that PBlaster can get to the Idle Screw Threads via the Pilot Jets.

Really? So it has to travel past the needle tip and then the o-ring??

Amazing stuff that PB Blaster

[Designer]

Oh,.....one more thing,.......there is a way that PBlaster can get to the Idle Screw Threads via the Pilot Jets.

Really? So it has to travel past the needle tip and then the o-ring?? Amazing stuff that PB Blaster

Had you the degree of the numerous experiences that I have had,....you would see that it is indeed amazing stuff.

[hillsy]

Oh,.....one more thing,.......there is a way that PBlaster can get to the Idle Screw Threads via the Pilot Jets.

Really? So it has to travel past the needle tip and then the o-ring?? Amazing stuff that PB Blaster

Had you the degree of the numerous experiences that I have had,....you would see that it is indeed amazing stuff.

[Designer]

Oh,.....one more thing,.......there is a way that PBlaster can get to the Idle Screw Threads via the Pilot Jets.

Really? So it has to travel past the needle tip and then the o-ring?? Amazing stuff that PB Blaster

Had you the degree of the numerous experiences that I have had,....you would see that it is indeed amazing stuff.

Your childish ridicule in posting such as you did is NOT welcome here, hillsy.

Please,...do at least Try to overcome your impulses to post like that when someone mentions their Technical Experiences.

[hillsy]

Seriously - do you think PB Blaster is going to go through a potentially blocked passage, then past the needle tip with a ridiculously fine tolerance (and again probably blocked) then past an o-ring that has been squashed in the orifice for over 20 years to get to the needle threads that are exposed on the other side?

Talk about ass-backwards.

So 00Vs1400GLP - when you tried to remove the screw before did you try and turn it in as well as just straight out? If you can do that and just get it to wiggle back and forth then the penetrating fluid should flow down the threads and hopefully make it easier to back out. Keep wiggling it with heaps of fluid and it should free up. Good luck!