popping out of carb filters

[oldyam80sg]

I rode the bike today and upon startup, get a popping out the carbs where the airbox would go(I have a filter setup). Goes away after a few minutes. I also am seeing the #4 carb boot is cracked and looks like it is sweating when it warms up. It looks wet but are these 2 things related? The other boots don't look half as bad. Also get a slight blue smoke upon warming up. I recently syphoned oil out as stated in a previous post due to overfilling. Plugs are nice light brown in color.

[Forden]

I had a similar issue on my GS--#4 would pop out of the back of the carb on choke, and got hot faster than the others--I figured it was lean on startup/under choke, and now before starting I make sure the bike is level and prime the carbs completely. Problem basically went away. Different carbs (VM's), maybe won't help but might be worth a try.

[cajun31]

I rode the bike today and upon startup, get a popping out the carbs where the airbox would go(I have a filter setup). Goes away after a few minutes. I also am seeing the #4 carb boot is cracked and looks like it is sweating when it warms up. It looks wet but are these 2 things related? The other boots don't look half as bad. Also get a slight blue smoke upon warming up. I recently syphoned oil out as stated in a previous post due to overfilling. Plugs are nice light brown in color.

Need more details. Is the bike at operating temperature or not when the popping occurs. Are you still on choke or not? Generally popping at the carbs indicates out of tune carb. The smoke should go away eventually if the only problem was too much oil. The carb intake manifold looking wet puzzles me. Could be that carb float is stuck and the carb is flooding but if that were the case you should see that. When the oil was too full it wasn't due to gas overflow was it?

[Socer4m]

HI Old Yam,,,,suggest spray some carb cleaner around the boot and vac lines while its running to see if there is a leak, if no change in idle speed, do a carb balance/synch with whatever gauges you have, I use the 4 vacuum gauges and it is easy and works great,,,,just connect to each vac post in each boot, flip to prime on petcock, idle and adjust.....there is lots of info to synch on the search section,,,,hope you get it figured out,,,Mike in San Diego/Pa.

[Socer4m]

almost forgot,,,,,IF THERE IS ANY GAS IN THE OIL IT WILL POP,,,,I didnt know if you checked your oil but if there is any leakiing of the carbs into the crankcase the gas vapor will cause popping and run like CRa xxxp, maybe stick a stick into the oil in the oil fill plug and smell it,,,if it has any gas smell,,,,that indicates gas is getting in your oil,,,,you can also try lighting the oily stick with a match, if it lights up that also indicates gas in the oil,,,,easy fix, just change oil,,,,but you will have to check the float needles for leaking also.........good luck again,,,,Mike in San DIego

[oldyam80sg]

The bike only pops on choke and then goes away when it warms up. The oil issue was me overfilling it. I checked the oil and no gas smell and I lit it on fire but didn't light. I put some RTV on boot # 4 to seal the crack in it until my new manifold boots arrive. The bike runs excellent, no hesitation whatsoever. I synced the carbs a month ago.

[LAB3]

The bike runs excellent, no hesitation whatsoever. I synced the carbs a month ago.

The guy who "Broke me in" on working on bikes had some sage wisdom.

"My bike is making a funny noise"
"Does it run OK?"
"Yes"
"Tighten the chin strap on your helmet so you don't have to listen to it"

40+ year old bikes have their quirks, knowing that there's more to do (intake boots) you might wanna consider his advice!

[oldyam80sg]

Waiting on my intake boots to come in.In the meantime ,I put some RTV on the cracked boot so will see today what the results are.

[LAB3]

Got to thinking about it. When gasoline evaporates the gasses get colder, that ight be what's causing the "sweat" you're seeing on that boot. Not sure if it's due to too lean or too rich, does the condensation smell like fuel?

[oldyam80sg]

No condensation does not smell like fuel. I started the bike today after putting on the RTV yesterday and less popping. It seems to be coming with the air filter off at the air pilot jets.

[cajun31]

No condensation does not smell like fuel. I started the bike today after putting on the RTV yesterday and less popping. It seems to be coming with the air filter off at the air pilot jets.

with everything you have described I would suspect that your pilot jet screws are not tuned optimally. The only reason I can think of that would cause the popping. I always tune by with the colortune. I turn them out until I see the first hint of orange then a half turn back in and they are good. When they are off you will experience popping as you have described.

[oldyam80sg]

I hate to start playing with pilot jet screws for 2 minutes of popping. Bike runs real good. I will take off the carbs to replace the intake manifold boots and look if anything might be dirty.

[bikerphil]

If the bike isn't ridden that much, it could be the ethanol gas starting to "do it's thing" to the pilot circuit.

[oldyam80sg]

I took off the air filter today to observe what is happening. Each carb when it runs on half choke, puffs of air are felt when I put my hand close to the opening where the filter would go. It is mostly #2 and #3 carb. Occasionally #1 and #4.This lasts until the choke is pushed in all the way and then it stops when it is warmed up. The bike runs great without an issue. I know it was mentioned by Cajun to Colortune but don't like results that I have read on that.