Pinging noise in exhaust at high rpm

beachcarter · 11-18-2013, 02:33 PM

Hey guys, I have a pinging sound in my exhaust at high rpm. It has been there since day one of installing my duromax 16 but I've had so many other issues to work out that I'm just now addressing this issue. As a refresher I've been on a quest to find a quiet muffler for my cart. I've been running the stock duromax muffler lately with some what ok sound level. Still louder than I like but it is acceptable. Anyway the exhaust pipe broke due to the muffler not being supported so I ordered a new pipe kit and took it to my friend who has a welder along with my walker tractor muffler. Figured we would give it a try. He made a steel bracket and welded it to the muffler drilled holes in it to align up with the bolts on the ezgo rear diff. The muffler now is supported by the rear diff and is angled down at a 45* angle. The entire install looks great. The muffler however is louder than the stock duromax muffler. Not happy about that but thinking about findin some sort of exhaust silencer to add to the tailpipe of the new muffler. Anyway, I have this pinging noise in the muffler at high rpm. The stock duromax muffler did the same thing. I also have a backfire problem when coming off the throttle at high rpm. I had it before with the stock duromax muffler but its worse now with the less restrictive tractor muffler. Im fairly certain the backfire is due to it running too rich. The engine would bog down at high rpms and fall on its face then suddenly pick back up. This went away after adjusting the needle in the carb to lean it out as much as possible. The carb is a mikuni 30mm slide carb with a 270 jet. The needle is adjusted as low as it can go to lean it out. I have a 260 jet in my mailbox waiting on me to get home and install it. Hopefully this cures my backfiring problem but does anyone have any idea what the pinging noise could be?

slonomo · 11-18-2013, 03:58 PM

How high of rpm do you hear the ping? It could be detonation. You could try some higher octane fuel and see if it goes away. If that's not it, might be a valve floating. If you run at a really high rpm you should upgrade to stiffer valve springs to prevent this.

beachcarter · 11-18-2013, 07:05 PM

Quote:

Originally Posted by slonomo

How high of rpm do you hear the ping? It could be detonation. You could try some higher octane fuel and see if it goes away. If that's not it, might be a valve floating. If you run at a really high rpm you should upgrade to stiffer valve springs to prevent this.

Pinging starts at 3/4 to full throttle. Update: installed the 260 jet. The backfiring has reduced, but not completely gone, the pinging is gone though. Problem now is I cant get the engine to idle. With the 270 jet I had no problems with it idling. I could start the engine, release the parking brake and get off the cart and it wouldnt move. Now I cant even shift it to reverse with the engine running. I have turned the idle screw out so far that it came out. Any ideas?

slonomo · 11-18-2013, 07:59 PM

Quote:

Originally Posted by beachcarter

Pinging starts at 3/4 to full throttle. Update: installed the 260 jet. The backfiring has reduced, but not completely gone, the pinging is gone though. Problem now is I cant get the engine to idle. With the 270 jet I had no problems with it idling. I could start the engine, release the parking brake and get off the cart and it wouldnt move. Now I cant even shift it to reverse with the engine running. I have turned the idle screw out so far that it came out. Any ideas?

Idle jet needs changed. What size are you running now?

BIKERMIKEYBLACK · 11-18-2013, 11:23 PM

Hey beach how did u mount the 30 mm mikuni to the duro ive been trying to figure that out for mine down the road
Thx

beachcarter · 11-19-2013, 07:26 AM

Slo, I didn't know there was an idle jet. Dont know what size I am running now. Guess I will have to find a breakdown diagram of this carb and see where that jet is located. The jet I replaced was very easy to get to. All I did was remove the bowl, unscrew the jet install the new jet and replace the bowl. That jet was a 270, I replaced it with a 260.

Biker, I don't know if you followed any of my other threads but my carb came as a complete kit with the engine, cradle, clutch, exhaust and all cables to complete the installation. The kit came with a billet aluminum carb adaptor that bolts to the stock duromax carb adaptor. It also has a fitting for my vacuum line for my fuel pump. I don't know how to post pics on here because I don't use a computer to access this site. I use my phone and tablet, but if you pm me your email address ill email you some pics.

DOOmsman · 11-19-2013, 10:00 AM

beachcarter · 11-19-2013, 10:18 AM

That diagram doesn't really explain much. I'm assuming the jet that I replaced is the main jet. I need to identify the idle jet. I thought there were only 2 jets but now I'm reading there is a needle jet and a pilot jet or are they the same thing. I know nothing about tuning a carb. There is an air mixture screw on my carb. Does that need to be adjusted at all? Can that cause my backfire, maybe too much or too little air? To be ckear I have a 30mm mikuni slide carb.

DOOmsman · 11-19-2013, 10:46 AM

Beach carter there is a ton of information about mikuni carbs
on the net. A lot of charts, diagrams and such.
Try Google.

beachcarter · 11-19-2013, 11:06 AM

I have but I'm not finding the info I'm looking for. I simply need to know what the idle jet is.

11-18-2013, 02:33 PM	#1
beachcarter Gone Wild Join Date: Jun 2011 Posts: 441	Pinging noise in exhaust at high rpm Hey guys, I have a pinging sound in my exhaust at high rpm. It has been there since day one of installing my duromax 16 but I've had so many other issues to work out that I'm just now addressing this issue. As a refresher I've been on a quest to find a quiet muffler for my cart. I've been running the stock duromax muffler lately with some what ok sound level. Still louder than I like but it is acceptable. Anyway the exhaust pipe broke due to the muffler not being supported so I ordered a new pipe kit and took it to my friend who has a welder along with my walker tractor muffler. Figured we would give it a try. He made a steel bracket and welded it to the muffler drilled holes in it to align up with the bolts on the ezgo rear diff. The muffler now is supported by the rear diff and is angled down at a 45* angle. The entire install looks great. The muffler however is louder than the stock duromax muffler. Not happy about that but thinking about findin some sort of exhaust silencer to add to the tailpipe of the new muffler. Anyway, I have this pinging noise in the muffler at high rpm. The stock duromax muffler did the same thing. I also have a backfire problem when coming off the throttle at high rpm. I had it before with the stock duromax muffler but its worse now with the less restrictive tractor muffler. Im fairly certain the backfire is due to it running too rich. The engine would bog down at high rpms and fall on its face then suddenly pick back up. This went away after adjusting the needle in the carb to lean it out as much as possible. The carb is a mikuni 30mm slide carb with a 270 jet. The needle is adjusted as low as it can go to lean it out. I have a 260 jet in my mailbox waiting on me to get home and install it. Hopefully this cures my backfiring problem but does anyone have any idea what the pinging noise could be?
beachcarter Gone Wild Join Date: Jun 2011 Posts: 441

11-18-2013, 03:58 PM	#2
slonomo Searching for The Way Join Date: Oct 2009 Location: Medina, Ohio (NEOHIO) Posts: 11,441	Re: Pinging noise in exhaust at high rpm How high of rpm do you hear the ping? It could be detonation. You could try some higher octane fuel and see if it goes away. If that's not it, might be a valve floating. If you run at a really high rpm you should upgrade to stiffer valve springs to prevent this.

11-18-2013, 11:23 PM	#5
BIKERMIKEYBLACK Gone Wild Join Date: Jun 2011 Location: Kingston Springs Tn. Posts: 874	Re: Pinging noise in exhaust at high rpm Hey beach how did u mount the 30 mm mikuni to the duro ive been trying to figure that out for mine down the road Thx

11-19-2013, 07:26 AM	#6
beachcarter Gone Wild Join Date: Jun 2011 Posts: 441	Re: Pinging noise in exhaust at high rpm Slo, I didn't know there was an idle jet. Dont know what size I am running now. Guess I will have to find a breakdown diagram of this carb and see where that jet is located. The jet I replaced was very easy to get to. All I did was remove the bowl, unscrew the jet install the new jet and replace the bowl. That jet was a 270, I replaced it with a 260. Biker, I don't know if you followed any of my other threads but my carb came as a complete kit with the engine, cradle, clutch, exhaust and all cables to complete the installation. The kit came with a billet aluminum carb adaptor that bolts to the stock duromax carb adaptor. It also has a fitting for my vacuum line for my fuel pump. I don't know how to post pics on here because I don't use a computer to access this site. I use my phone and tablet, but if you pm me your email address ill email you some pics.
beachcarter Gone Wild Join Date: Jun 2011 Posts: 441

11-19-2013, 10:00 AM	#7
DOOmsman Gone Wild Join Date: Jul 2008 Location: Reddick IL Posts: 11,220	Re: Pinging noise in exhaust at high rpm

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11-19-2013, 10:18 AM	#8
beachcarter Gone Wild Join Date: Jun 2011 Posts: 441	Re: Pinging noise in exhaust at high rpm That diagram doesn't really explain much. I'm assuming the jet that I replaced is the main jet. I need to identify the idle jet. I thought there were only 2 jets but now I'm reading there is a needle jet and a pilot jet or are they the same thing. I know nothing about tuning a carb. There is an air mixture screw on my carb. Does that need to be adjusted at all? Can that cause my backfire, maybe too much or too little air? To be ckear I have a 30mm mikuni slide carb.
beachcarter Gone Wild Join Date: Jun 2011 Posts: 441

11-19-2013, 10:46 AM	#9
DOOmsman Gone Wild Join Date: Jul 2008 Location: Reddick IL Posts: 11,220	Re: Pinging noise in exhaust at high rpm Beach carter there is a ton of information about mikuni carbs on the net. A lot of charts, diagrams and such. Try Google.

11-19-2013, 11:06 AM	#10
beachcarter Gone Wild Join Date: Jun 2011 Posts: 441	Re: Pinging noise in exhaust at high rpm I have but I'm not finding the info I'm looking for. I simply need to know what the idle jet is.
beachcarter Gone Wild Join Date: Jun 2011 Posts: 441

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