Exhaust popping @ idle & deceleration

[rjsteiner01]

Hello folks, I'm new to the site and have enjoyed the various threads. I have read up on exhaust popping but I think I have an other than "lean" condition. I will try not to be long winded but want to give those out there all the info I have on the symptoms/condition.

 

Bought the bike with 21K miles.

I get about 25 miles to the gal

Popping from both sides but mostly from the right at idle and deceleration.

Compression check, bike at normal temp/then added a little oil, #1-185/190, #2-180/180, #3-180/185, #4-160/165

Bike fowled out #3 & 4 plugs after putting a few hundred miles on it and I had to limp back to the house, new plugs and ran great.

Bike has K & N air intake, drilled exhaust pipes

Inspected carbs and floats/jets. Found idle mixture screws out collectively 3.5 on the left and 12.75 on the right!

I turned all to 1.5 from seated and synced the carbs, got rid of a lot of the popping but still fowling out right side #3 & 4. Turned in right side to .75 open and after two tanks of gas the plugs look like they are burning correctly and I further reduced the popping but I still have it on the right side only @ idle.

If I am cursing in 4th without loading the bike I hear a ping in the right front cylinder every so often like improper ignition timing (I checked timing @ idle and it was with in the little window) Seems like a valve sticking open or maybe burnt?

My compression is low in accordance with the manual, is this due to burnt or sticky exhaust valves?

I would think that this bike should not be worn out (ring/cylinder) @ 21K miles

Can I get away with operating it until a winter dismantle?

Could a K & N filter and drilled pipes caused a lean condition?

Looking forward to your input.

[djh3]

Being as your compression didnt jump significantly I would say the bottom end (rings/pistons) are OK. You are a little early on the valve check but it may definatly be worth your while. The fuel milage is hurendous imop. My RSV gets in the 36-40 range. Sounds more carb related to me, given that the settings are so mis match. Maybe a diaphram has a hole in it or a jet or something is clogged. Have you tried running sea foam or Berrymans B 12 thru it yet? When you sync'd the carbs did you have to make a bunch of turns to get aligned?

[lonewolf96]

With everything you are describing it sounds to me like you are dumping more fuel in than you need and not running on the lean side. This would cause the plugs to foul, be really black and sooty, and also can cause a lot of carbon buildup on the valves which could cause the lower compression. It sounds like someone has really been screwing around with your carbs. If it were me, I'd pull the carbs and check the jets to make sure they are in the correct locations and of the correct size. The jets for these carbs are not all the same size from one carb to the next from the factory and if they get moved to the wrong carb it will cause some issues. There is also a Carb jet kit out there that some people seem to think they need after adding K&N filters and drilling the mufflers but it's not needed. If the previous owner installed that jet kit then it will cause a lot of what you are describing, it was designed for the 90's model TD not the '05 and up models (they have different carbs). I had a friend try the jet kit on his RSV and had the same issues you are describing, didn't take him long to decide to remove it and go back to stock. I'd also check the float levels while I was in there as that has some affect on your MPG. There are a couple of really useful threads on removing and adjusting the carbs in the tech section.

Edited July 2, 2013 by lonewolf96
I can't type

[MiCarl]

I agree with lonewolf96. Somebody that knows what they are doing or who has a lot of time to learn needs to really go through those carburetors.

[dacheedah]

agreed running rich, check floats maybe a colortune and sync.

[rjsteiner01]

Being as your compression didnt jump significantly I would say the bottom end (rings/pistons) are OK. You are a little early on the valve check but it may definatly be worth your while. The fuel milage is hurendous imop. My RSV gets in the 36-40 range. Sounds more carb related to me, given that the settings are so mis match. Maybe a diaphram has a hole in it or a jet or something is clogged. Have you tried running sea foam or Berrymans B 12 thru it yet? When you sync'd the carbs did you have to make a bunch of turns to get aligned?

 

I did have to make a bunch of turns to get them sync'd, no holes in diaphragms, no obstructions in jets, I will get some sea foam as it couldn't hurt. I did the sync last weekend and haven't really had it on the road to see the improvement in mpg, will let you know. Thanks for the input, how do you do a simple reply without the quote??

[rjsteiner01]

With everything you are describing it sounds to me like you are dumping more fuel in than you need and not running on the lean side. This would cause the plugs to foul, be really black and sooty, and also can cause a lot of carbon buildup on the valves which could cause the lower compression. It sounds like someone has really been screwing around with your carbs. If it were me, I'd pull the carbs and check the jets to make sure they are in the correct locations and of the correct size. The jets for these carbs are not all the same size from one carb to the next from the factory and if they get moved to the wrong carb it will cause some issues. There is also a Carb jet kit out there that some people seem to think they need after adding K&N filters and drilling the mufflers but it's not needed. If the previous owner installed that jet kit then it will cause a lot of what you are describing, it was designed for the 90's model TD not the '05 and up models (they have different carbs). I had a friend try the jet kit on his RSV and had the same issues you are describing, didn't take him long to decide to remove it and go back to stock. I'd also check the float levels while I was in there as that has some affect on your MPG. There are a couple of really useful threads on removing and adjusting the carbs in the tech section.

 

I have 1997 TD with 28mm carbs and was not aware that the jets were different from one carb to the next, I will consult my manual for jet size and location. Previous owner may have re-jetted as you pointed out and made things worse. I was in the carbs inspecting but did not record jet #s . Float levels were all the same and I was only having fowling on right side. I could not find any info on how to set those idle screws, I guess you have to have a co analyzer to do it correctly. I'm sure I do have a carbon deposit problem as you describe (based on plugs & muffler drain hole deposits on my carport floor upon start up), what's a good way of dealing with it other than head removal? I have sync'd carbs and turned in on idle screws for # 3 and 4, I will run a few tanks through and check plug condition and let you know. many thanks for your input.

[rjsteiner01]

agreed running rich, check floats maybe a colortune and sync.

 

What's a colortune?

[Yammer Dan]

1st thing "I" would do is dump a whole can of BerryMan's Chem Tech in less than a 1/2 tank and run it hard!!! Leave sit at least overnight with this mixture in it and in the carbs good before you refuel. Then reset idle screws and sync.

A Color-Tune is a thing that lets you look into the cylinder while adjusting carbs to see how they are firing. From red, too rich. Blue, getting close. Real light Blue or white. Too lean. Do a search on Gunnison Color-Tune.