"80"SG help in the Philippines please!!

[hanger10]

Howdy guys! I havent posted in quite a while, coz all of the advice Ive gotten from here has kept the ole beast up and running for quite a while. I shimmed the valves about 8 mos ago, so my new problem shouldnt be that. In the last month or so, I have developed a pop, maybe a backfire, but I dont think so, whenever I let off the gas. And, taking off at low rpm, it will miss just a little. It seems like, the warmer the bike gets, the worse the popping gets when I let off the gas. The bike has new 3ohm coils and wires, so that shouldnt be it. I took it on a 100 mile ride this weekend, and got 35+mpg, so its getting good mileage. Ive included a link to a video on youtube that I made, so you can hear the popping. Please help get the ole dinosaur running smoothe again! Any ideas what is causing it??? Thanx for all the help in the past, and in advance for the help this time!!! Mabuhay from Liloan, Cebu, Philippines.

Randy

Here is the video- http://www.youtube.com/watch?v=9uYN3GtjhcE

[BA80]

First Randy, check for exhaust leaks, Especially around where the header is sealed at the head. That's a common thing that will cause popping on deceleration.

If you don't find any leaks causing the problem, check your plugs for any cylinders(s) that my seem to be running lean. If any plugs a lighter color than a nice light to medium tan, try opening the idle mixture screw on that cylinder and see if that makes a difference. A lean condition during decelleration can cause that if the idle circuit is a bit lean.

My 2 cents

A 4 into 1 system seems to like to pop a little anyway.

[bikerphil]

I had a similar problem with a lean/popping condition, turned out to be leaks on the head side of the intake boots. Took them off, cleaned off the old gasket, used RTV instead of gaskets. Runs like new now. Not sayin' for sure this is your problem, somthing to consider.

[hanger10]

Greg, my friend here that works on the bike has done both, but would like to try for myself. Exactly how do you check the exhaust for leaks where it bolts onto the head? My first guess was exhaust leak but he said no. I will check the plugs first chance I get this week. I know the proper color, so that shouldnt be a problem. The last time he did check the plugs, all was fine, but I will do it again. I know (hopefully!) its something small, sometimes just so damned hard to find the small problems!!!! Thanx for the reply.

Randy

[hanger10]

I put new intake boots on it 3 yrs ago, so hadnt thought of that being the problem! Will check that also! Thanx Bikerphil!

[BA80]

If you just take a piece of vacuum hose, 2' or so, stick 1 end in your ear ( no not a joke) and run the other end around the flange at the head with the engine running and you'll be able to hear even the smallest leak.

I don't know any other way of isolating a lean cylinder other than with the plugs or a blue header pipe.

If you don't find any leaks or obvious signs of being lean you could try opening the idle mix screws 1/2 turn, one at a time and test riding to see which one makes a difference.

There is a way of setting the mixture with a vacuum guage setup but it doesn't sound like you are equiped.

What Phil said also.

[jetmechmarty]

You picked up some trash in your fuel. One or more of your pilot jets has become clogged. Clean them and their respective circuits and the problem will go away.

[skids]

I would try seafoam or techron first.

[hanger10]

Marty, the fuel here in the Philippines is notorious for trash!!!!

Randy

[jetmechmarty]

Marty, the fuel here in the Philippines is notorious for trash!!!!

Randy

Randy,

I would not waste time. Pull the carburetors and clean the pilots. You'll be right back in business. You should probably be running some sort of fuel filters, if you aren't already doing so.

[BA80]

You should probably be running some sort of fuel filters, if you aren't already doing so.

+1......especially if you KNOW there's a good possibiliy there's junk in the gas.

[Vinnie48]

Hi Randy,

Mabuhay! Looks like I have similar issue as yours... how did it go ?
Was it fixed ?

[hanger10]

Hi Vinnie. Left my bike at mechanic friends place last nite. Carb parts were soaked overnight in solvent, getting cleaned as I speak, and tank getting flushed. Leaving to watch, will be done this afternoon, will let you know how it turns out!!

Randy

[Rasputin]

I had a similar problem with a lean/popping condition, turned out to be leaks on the head side of the intake boots. Took them off, cleaned off the old gasket, used RTV instead of gaskets. Runs like new now. Not sayin' for sure this is your problem, somthing to consider.

I recently had a similar issue with one of my XS11's. It had always run strong and had no issues. One fine day I went out to ride and had the popping you describe. Damn near drove me crazy trying to figure out why it was doing that as it had always run great. Turns out it was as simple as a Blind plug on the carb boots had developed a leak and simply replacing it solved the problem. I vote for the intake side leak as the problem.

[BA80]

DON'T use those chincy paper boot gaskets. They will fail.