| Author | Message | ||
     Jeepme79 |
Last week my S2 started backfiring on deceleration, and occasionally at idle. I ran some seafoam through about 1/2 a tank of gas, and pulled the plugs to replace them. The front plug looked fine, but the rear had some white deposits on it leading me to believe it is running a little lean. The bike has 33k on it, I've put on the last 10k with no problems at all. My first thought would be a plugged jet or leaky intake gasket. Any other ideas? sorry, this is a 95 thunderbolt | ||
| Mtkawboy |
if it just started doing it and never did it before Id be looking for an intake leak on the rear cyl. The carb only has 1 pilot jet that feeds both cylinders so its unlikely its blocked. Spray some WD40 around the intake to head o-ring and see if the idle speed picks up. | ||
| Jeepme79 |
That's exactly what I was thinking. I'll check tomorrow night. Is that hard to change? | ||
| Ratbuell |
Close petcock, run bike until it is out of fuel. Remove fuel line from petcock. Remove tank. Remove aircleaner, carburetor retaining plate, and carburetor. Carb is easier to drop out of the way if you take the choke knob off the bracket - loosen the nut behind it and it will drop out of the notch. DO NOT OVERTIGHTEN when you reinstall, or you'll break the plastic!!! Remove bolts that hold intake to the heads. Install new gaskets (do 'em all while you're there...front and rear, as well as the carb mounting ring). I usually install the gaskets with a schmear of engine oil on them, so they glide into place and don't bunch up when tightening the bolts. Installation is the reverse of removal. | ||
| Sportyeric |
To add to Ratbuell's instructions, you may need to take a hacksaw or dremel cutting wheel to an allen wrench in order to get it to fit the intake manifold bolts. | ||
| Jeepme79 |
Tested it tonight and just as expected the rear gasket is bad. Headed to the shop for parts tomorrow. Thanks for the help guys. | ||
| Mtkawboy |
Those ball socket end allen wrenches are real handy for tight spots. Not sure what the real name is for them but they let you turn from an angle | ||
| Jeepme79 |
Finally got around to working on the bike tonight. 3 of the 4 were a bit of a struggle getting out, the 4th (front cylinder, carb side) stripped the head. Not looking good right now, and I'm surely not riding it to work tomorrow. |
