Jump to content
IGNORED

Backfire


Recommended Posts

3000rpm and above

 

Sent from my LG-M255 using Tapatalk

 

Actually pretty good. It will pop every now and then at cruise but accelerates well and runs pretty smooth. I will get a little popping when I decelerate but the loud backfire starts again at idle.

Link to comment
Share on other sites

  • Replies 88
  • Created
  • Last Reply

Top Posters In This Topic

Actually pretty good. It will pop every now and then at cruise but accelerates well and runs pretty smooth. I will get a little popping when I decelerate but the loud backfire starts again at idle.
Sounds kinda like blocked passages did you rebuild the carbs ? If so do you replace the idle jets? How did you clean the carb body? But there is air getting in there somewhere.

 

Sent from my LG-M255 using Tapatalk

Link to comment
Share on other sites

Actually pretty good. It will pop every now and then at cruise but accelerates well and runs pretty smooth. I will get a little popping when I decelerate but the loud backfire starts again at idle.

 

Just a thought when you have a minute switch 4 with any other spark plug

Link to comment
Share on other sites

Steven G. I agree with your analysis of a possibility of stuck rings. We could also have a problem with carbon around the valve heads and maybe the valve stems. I would encourage the OP to follow your instructions of fogging of the engine. I have never tried Deep Creep to free rings. I usually use Yamaha's ring free or Amsoil's PI. Have had good luck with both of these.

The op should do this after he gets his carbs clean.

What is fogging?

 

Sent from my LG-M255 using Tapatalk

Link to comment
Share on other sites

Sounds kinda like blocked passages did you rebuild the carbs ? If so do you replace the idle jets? How did you clean the carb body? But there is air getting in there somewhere.

 

Sent from my LG-M255 using Tapatalk

 

Cleaned the carb body with carb cleaner and a brush. The kit I bought included the float bowl o-ring, float needle and valve assembly and o-rings. It did not include the idle jets. I have had them off twice now and only have had a problem with number 4 cylinder. Since it looks like I will be pulling them off again maybe I should get new jets? So frustrating. I have had this bike down to engine and frame and now I have one cylinder holding me up. If nothing else I am learning a ton about the bike. I was a little over whelmed when I first got it. Sooner or later I'll get it running to perfection.

bike99.jpg

Link to comment
Share on other sites

Cleaned the carb body with carb cleaner and a brush. The kit I bought included the float bowl o-ring, float needle and valve assembly and o-rings. It did not include the idle jets. I have had them off twice now and only have had a problem with number 4 cylinder. Since it looks like I will be pulling them off again maybe I should get new jets? So frustrating. I have had this bike down to engine and frame and now I have one cylinder holding me up. If nothing else I am learning a ton about the bike. I was a little over whelmed when I first got it. Sooner or later I'll get it running to perfection.

 

Well there is a guy who sells the engine rebuild and the carb rebuilds CD and he tells you in that video to replace the idle jets you. His reason is pretty simple he cleaned carbs previously and thought he had the jets good but they still gave him hell so best to just do it once. I am sure someone has the info about the cds I have them somewhere but don't remember what thread it was in.. we are trying to help you knock out the possiblities and also have you got your mixture screws out? Or do they still have the stupid caps over them. I am not too certain on the newer Ventures but I would imagine you still can gain access to those by drilling out the cap.

Link to comment
Share on other sites

To do it right, the carbs need to be stripped and then soaked in carb cleaner. There are lots of passages in these carbs.

 

I have the CD mentioned. The name in the return address on the CDs is:

 

Dean Dietrick from DEPERE WI

 

His email is in this thread

 

https://www.venturerider.org/forum/showthread.php?119186-Bought-Carb-Rebuild-Video-by-Damon-Ferraiuolo

Link to comment
Share on other sites

Well there is a guy who sells the engine rebuild and the carb rebuilds CD and he tells you in that video to replace the idle jets you. His reason is pretty simple he cleaned carbs previously and thought he had the jets good but they still gave him hell so best to just do it once. I am sure someone has the info about the cds I have them somewhere but don't remember what thread it was in.. we are trying to help you knock out the possiblities and also have you got your mixture screws out? Or do they still have the stupid caps over them. I am not too certain on the newer Ventures but I would imagine you still can gain access to those by drilling out the cap.

 

snyper

 

I will look into those CDs. I do have the mixture screws out. I have tried to set them on that carb withut much luck. If I turn the screw all the way in the backfire stops. Obviously shutting off the fuel. It will start to backfire as I turn the screw out at about 3/4 of a turn and get worse as I continue out. All of the others are set right around two turns out.

Link to comment
Share on other sites

To do it right, the carbs need to be stripped and then soaked in carb cleaner. There are lots of passages in these carbs.

 

I have the CD mentioned. The name in the return address on the CDs is:

 

Dean Dietrick from DEPERE WI

 

His email is in this thread

 

https://www.venturerider.org/forum/showthread.php?119186-Bought-Carb-Rebuild-Video-by-Damon-Ferraiuolo

 

Thanks I will look into that.

Link to comment
Share on other sites

"Cleaned the carb body with carb cleaner and a brush. The kit I bought included the float bowl o-ring, float needle and valve assembly and o-rings. It did not include the idle jets. I have had them off twice now and only have had a problem with number 4 cylinder. Since it looks like I will be pulling them off again maybe I should get new jets? So frustrating.""" Did you soak and spray clean passages, jets, and blow through using 80ish pounds?

 

After you look through chapter 6 let us know what you don't remember removing and cleaning, that may trigger an answer

 

I am including 2 links, one is out of the gen 2 library the other is the pdf I am using. Chapter 6 shows the carbs. I think we are confusing results when we aren't using the same terminology.

 

In the second link there are some very good pictures showing Don Murray & Freebird jetting. Pay close attention to the pilot jet with emulsion tube, did you remove and check/clean these.

 

Also take a look at the needle on 4 take a pic when you pull it out so we may see if there has been changes or a mistake.

Did you swap the plugs?

 

For now and of course the decision is yours, I would change jet sizes till we settle the bike down.

 

If only 2 had been 150psi

 

http://www.werder.ee/Manual/XVZ1300.pdf

 

https://www.venturerider.org/forum/showthread.php?502-Re-Jetting-Carbs

 

This link is for the AIS system curious if yours has been altered? But it has to do with deceleration.

https://www.venturerider.org/forum/showthread.php?485-Plugging-the-AIS

Link to comment
Share on other sites

What is fogging?

 

Sent from my LG-M255 using Tapatalk

 

Fogging is just a preventative extra we do when storing an engine. In more extreme situations such as stuck rings we try to free them by soaking the cylinder/jug with a chem that will penetrate the carbon binding the ring which is in fact a spring stuck firmly to what is referred to as the ring landing

 

When we have a whatever that causes a compression loss we generate way too much carbon, just like a healthy engine will if the jets are to large or we choose to run to rich a mix/ say like running on the choke too long!

 

Important to note that 10:1 cost more to build. And what we get in return is something closer to stoichio all the while using less fuel or smaller jets, (we can of course choose larger) yet still extracting sufficient heat energy which then is measured in expansion. By knowing the stroke design can choose how much ignition, heat expansion will be at the BTC which is then tossed out with the remaining ignition or afterburn. Why is having to much unused energy at BTC important? Easy, no. 1 power stroke compresses no. 2 and so on.. If we choose to enlarge the jets then, our aim is for more punch at a given range but we sacrifice efficiency in the process.

 

Because of the exhaust system on these bikes they also cheat the scavenge effect so you have different jet sizing which is quite confusing. It is in a real sense compensating for the volume imbalance front and rear..

 

Now aren't you glad you asked;)

Link to comment
Share on other sites

I'm in Oklahoma

 

Lol A good reason to go chase some taco's in Tulsa LOL. We don't have a Jack in the Box here in Joplin. Too bad you aren't a bit closer I can't guarentee how much help I could be other then telling you what color you have in that cylinder but it could be an option... depending how next month looks. Or what the old lady wants to do.

 

Fogging is just a preventative extra we do when storing an engine. In more extreme situations such as stuck rings we try to free them by soaking the cylinder/jug with a chem that will penetrate the carbon binding the ring which is in fact a spring stuck firmly to what is referred to as the ring landing

 

When we have a whatever that causes a compression loss we generate way too much carbon, just like a healthy engine will if the jets are to large or we choose to run to rich a mix/ say like running on the choke too long!

 

Important to note that 10:1 cost more to build. And what we get in return is something closer to stoichio all the while using less fuel or smaller jets, (we can of course choose larger) yet still extracting sufficient heat energy which then is measured in expansion. By knowing the stroke design can choose how much ignition, heat expansion will be at the BTC which is then tossed out with the remaining ignition or afterburn. Why is having to much unused energy at BTC important? Easy, no. 1 power stroke compresses no. 2 and so on.. If we choose to enlarge the jets then, our aim is for more punch at a given range but we sacrifice efficiency in the process.

 

Because of the exhaust system on these bikes they also cheat the scavenge effect so you have different jet sizing which is quite confusing. It is in a real sense compensating for the volume imbalance front and rear..

 

Now aren't you glad you asked;)

 

Umm Where is the crickets playing there little feet and a very very confused look lol... So fogging is where I take trani fluid and dump it into a cylinder trying to free it up...

Link to comment
Share on other sites

"Cleaned the carb body with carb cleaner and a brush. The kit I bought included the float bowl o-ring, float needle and valve assembly and o-rings. It did not include the idle jets. I have had them off twice now and only have had a problem with number 4 cylinder. Since it looks like I will be pulling them off again maybe I should get new jets? So frustrating.""" Did you soak and spray clean passages, jets, and blow through using 80ish pounds?

 

After you look through chapter 6 let us know what you don't remember removing and cleaning, that may trigger an answer

 

I am including 2 links, one is out of the gen 2 library the other is the pdf I am using. Chapter 6 shows the carbs. I think we are confusing results when we aren't using the same terminology.

 

In the second link there are some very good pictures showing Don Murray & Freebird jetting. Pay close attention to the pilot jet with emulsion tube, did you remove and check/clean these.

 

Also take a look at the needle on 4 take a pic when you pull it out so we may see if there has been changes or a mistake.

Did you swap the plugs?

 

For now and of course the decision is yours, I would change jet sizes till we settle the bike down.

 

If only 2 had been 150psi

 

http://www.werder.ee/Manual/XVZ1300.pdf

 

https://www.venturerider.org/forum/showthread.php?502-Re-Jetting-Carbs

 

This link is for the AIS system curious if yours has been altered? But it has to do with deceleration.

https://www.venturerider.org/forum/showthread.php?485-Plugging-the-AIS

 

Patch

 

That is the same manual that I have along with a Clymer manual. Just glancing through the pictures in the carb link it looks like basically the same thing that I did but I will go through it more thoroughly when I have time. I have not done anything with the AIS system but I will look closer at that link also. I did blow air through all of the passages and also soaked the carbs. Apparently it worked for at least three of the carbs because they seem to be working fine. I have to say that the carbs were a mess when I first got the bike, very dirty and leaking badly. I intend to pull them again as soon as I can. I have not swapped out the plug yet. Thanks again.

Link to comment
Share on other sites

Lol A good reason to go chase some taco's in Tulsa LOL. We don't have a Jack in the Box here in Joplin. Too bad you aren't a bit closer I can't guarentee how much help I could be other then telling you what color you have in that cylinder but it could be an option... depending how next month looks. Or what the old lady wants to do.

 

 

 

Umm Where is the crickets playing there little feet and a very very confused look lol... So fogging is where I take trani fluid and dump it into a cylinder trying to free it up...

 

Appreciate the offer. I am curious about the colortune though. How do you like that tool? I have read good and bad things about them. I would certainly be willing to buy one if they really do work.

Link to comment
Share on other sites

Patch

 

That is the same manual that I have along with a Clymer manual. Just glancing through the pictures in the carb link it looks like basically the same thing that I did but I will go through it more thoroughly when I have time. I have not done anything with the AIS system but I will look closer at that link also. I did blow air through all of the passages and also soaked the carbs. Apparently it worked for at least three of the carbs because they seem to be working fine. I have to say that the carbs were a mess when I first got the bike, very dirty and leaking badly. I intend to pull them again as soon as I can. I have not swapped out the plug yet. Thanks again.

 

When you do pull them needless to say that 4 requires close inspection of each component, plunger, enricher needle and jets. We read that the carbs don't appear to be leaking from the blows but we do need to confirm that the jet sizes are matching no. 4 carb specs, change them late if you wish.

So recap check each piece and part number very closely, every jet and tube must be inspected...

 

Don't sell the spark plug short, a cracked insulator can fool the best of us.

 

Last year I had to pull a set of carbs way to often till finding a bad gasket was the grief, chit happens

 

Looked at the pic you posted of the bike torn down yikes Dude maga work right.

Link to comment
Share on other sites

When you do pull them needless to say that 4 requires close inspection of each component, plunger, enricher needle and jets. We read that the carbs don't appear to be leaking from the blows but we do need to confirm that the jet sizes are matching no. 4 carb specs, change them late if you wish.

So recap check each piece and part number very closely, every jet and tube must be inspected...

 

Don't sell the spark plug short, a cracked insulator can fool the best of us.

 

Last year I had to pull a set of carbs way to often till finding a bad gasket was the grief, chit happens

 

Looked at the pic you posted of the bike torn down yikes Dude maga work right.

 

Yes it was a lot of work but a great learning experience. Like I said I believe the bike had been sitting for some time. It actually ran when I first got it but the carbs started to leak pretty badly after a little riding and it also needed tires. Although the brakes weren't super bad I did them anyway along with changing all the fluids. I decided to just pull it apart and replace anything that needed replacing. It was awesome getting it on the road and riding it until I found out the number 4 cylinder was not firing. Even on three it has mega power. Can't wait to get it running on all four.

Link to comment
Share on other sites

Looking at my growing worksheet one question that came to mind was, did it backfire when you first road the bike?

And on the higher compression jugs, do they climb up fast say like 5 rotations and its close to the max?

The plugs are new or reused, gap set..... A new can crack as well

Link to comment
Share on other sites

Looking at my growing worksheet one question that came to mind was, did it backfire when you first road the bike?

And on the higher compression jugs, do they climb up fast say like 5 rotations and its close to the max?

The plugs are new or reused, gap set..... A new can crack as well

 

No it did not backfire when I first rode it. It also did not backfire after I put it back together after rebuilding the carbs. But I am not sure that the number 4 cylinder was firing when I first got the bike either. I'm guessing it wasn't. The backfire started after I pulled the carbs for the second time. The reason I pulled them the second time was because the number 4 cylinder was not firing. I am assuming that there was no backfire because there was no fuel getting to that cylinder until I replaced the carbs the second time. I didn't really notice how many rotations occurred to get to max but I don't believe it took a whole lot. Seemed to max out pretty quick on all cylinders. As far as the plugs they are all new and all gaped.

Link to comment
Share on other sites

No it did not backfire when I first rode it. It also did not backfire after I put it back together after rebuilding the carbs. But I am not sure that the number 4 cylinder was firing when I first got the bike either. I'm guessing it wasn't How some of us read this: If you have non firing cylinder, we 1st suspect spark, and you tested the coils all the way down to the plugs which we know now are new.

The backfire started after I pulled the carbs for the second time. The reason I pulled them the second time was because the number 4 cylinder was not firing. Having tested ignition and it passed natural to assume a carb problem. I have to ask, how did you know 4 was not firing? Cold Pipe?

I am assuming that there was no backfire because there was no fuel getting to that cylinder until I replaced the carbs the second time. Again for some of us we read it this way: if we are sure of spark then we want to check float or force a flooding of that carb. Here's why: if we know that fuel is getting into the blow then we can assume that the Pilot Circuit is plugged, a cold pipe at idle confirms this. But the trick to understand is that the carb will still produce past 1/4 throttle, providing there is fuel in the bowl! The backfire in the exhaust can be a bit of a bender, both lean and rich can cause it but the LOAD ones are almost always accumulated fuel. You mentioned a general timing to this, hmm, and is why I asked about the plug. But because you can't adjust the Pilot without backfire, well that's suggests Pilot circuit. It can also however mean that while your pilot circuit should be the only fuel supply/ so you can balance through the Pilot screw from 1 to 2 turns, it can't be the only circuit providing fuel! I hope you understand why I am explaining it this way. So what happens if you have a crossed and a leaking circuit: you cool the combustion/ it simply can't consume that amount of fuel at that throttle plate position! The mix gets tossed out and ignites in the pipe.

I didn't really notice how many rotations occurred to get to max but I don't believe it took a whole lot. Seemed to max out pretty quick on all cylinders. As far as the plugs they are all new and all gaped.

 

After you switch the plugs and if it still backfires then I would completely disassemble that no. 4 carb just like the blow up of the carb in chapter 6 plungers included, except the throttle shaft.

After you re install it I would figure a way to test the pipe temperatures, if they are close then button up the exhaust, get your rings soaked and ride it.

Post a pic of plug 4 if not too much trouble

Link to comment
Share on other sites

Just to make sure I've covered all the potentials I'm just going to toss this out there. If it were me and I suspect a misfire I could take my spark gap tester, set to to 5/8" put earplugs on and run the bike keeping an eye on the arc. If there is an intermittent spark problem above the plug then the interruption could line up with the backfire or close.

Link to comment
Share on other sites

After you switch the plugs and if it still backfires then I would completely disassemble that no. 4 carb just like the blow up of the carb in chapter 6 plungers included, except the throttle shaft.

After you re install it I would figure a way to test the pipe temperatures, if they are close then button up the exhaust, get your rings soaked and ride it.

Post a pic of plug 4 if not too much trouble

 

Yes the way I determined number 4 was not firing was a cold pipe which I determined by spraying water on it. I am planning on picking up a digital thermometer after I pull the carbs again. I know I am getting good spark on all cylinders, I have checked this more then once. When I turn the fuel mixture screw in on number 4 removing fuel from the system the backfire stops. Of course that cylinder stops firing also. As I turn it back out it will begin to backfire at about 3/4 of a turn and get progressively worse as I turn farther out. I will not be able to work on it until Saturday. I intend to pull the carbs, pull the right pipe and see if I can find that hole and also do the fogging. I need to find a place that has the deep creep.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...