mcman56 Posted August 7, 2009 Report Share Posted August 7, 2009 2002 2.9 started to develop a rolly lean sounding idle. It seemed to come on slowly. Oddly it was not affected by the mixture screw and did not produce any serious lean symptoms like big knock or bog but did get some minor knocking. Off idle performance was a bit weak and less predictable but otherwise performance was normal. I did a basic carb clean followed by a major carb and air box clean but it is still much the same. Mixture screw does not seem to make a difference. Any ideas? Could this be bad gas? The only odd thing is that I run a 33 pilot but have been running it for a few years with good success. Quote Link to comment Share on other sites More sharing options...
copemech Posted August 7, 2009 Report Share Posted August 7, 2009 2002 2.9 started to develop a rolly lean sounding idle. It seemed to come on slowly. Oddly it was not affected by the mixture screw and did not produce any serious lean symptoms like big knock or bog but did get some minor knocking. Off idle performance was a bit weak and less predictable but otherwise performance was normal. I did a basic carb clean followed by a major carb and air box clean but it is still much the same. Mixture screw does not seem to make a difference. Any ideas? Could this be bad gas? The only odd thing is that I run a 33 pilot but have been running it for a few years with good success. Most common thing would be water(condensation) in the tank. Empty it into a cut, clear plastic jug. Only takes that drop you may never see in the bowl of the carb. You can carefully break the bowl over a glass container, maybe! Also be sure to fully extract the pilot jet to clean and blow(backwards) through the 2 little holes in the carb bore with cleaner, needle screw removed. Ck Banjo filter! I have had to go richer on the pilot in recent years on the later bikes, which I muchly attribute to the oxigenated fuel. If you are having to run 3.5 or so turns out on the screw, you may want to go to a 35-36 pilot jet to get more in range. Hope that helps. Quote Link to comment Share on other sites More sharing options...
mcman56 Posted August 8, 2009 Author Report Share Posted August 8, 2009 I did notice a little water in the carb but figure that it was from all the washing I did with the tank off prior to removal. Yesterday, I dumped and air dried the gas tank and gas can plus cleaned the carb again. After warm up with fresh gas, the result was the same. It sounds just like it is running out of gas at 4 to 5 turns out on the mixture screw. At 3 it dies. The fan cycles a lot even though it is only in the 80s and bogs if the throttle is hit quickly. I don't see any signs of vacuum leaks. It certainly was not rich before this issue. I have a 34, 35 and 36 pilot so I could try a 35 but I don't know what could have changed. Does CA reformulate gas mid summer? Quote Link to comment Share on other sites More sharing options...
mcman56 Posted August 8, 2009 Author Report Share Posted August 8, 2009 Never put off until tomorrow........I put in a 35 pilot and it idles nicely at 2.5 turns out. It also chugs around the backyard OK but will have to wait for a full test. This does not explain the change. Maybe I was on the edge of lean and a change in the fuel pushed it over. Quote Link to comment Share on other sites More sharing options...
copemech Posted August 8, 2009 Report Share Posted August 8, 2009 I did notice a little water in the carb but figure that it was from all the washing I did with the tank off prior to removal. Yesterday, I dumped and air dried the gas tank and gas can plus cleaned the carb again. After warm up with fresh gas, the result was the same. It sounds just like it is running out of gas at 4 to 5 turns out on the mixture screw. At 3 it dies. The fan cycles a lot even though it is only in the 80s and bogs if the throttle is hit quickly. I don't see any signs of vacuum leaks. It certainly was not rich before this issue. I have a 34, 35 and 36 pilot so I could try a 35 but I don't know what could have changed. Does CA reformulate gas mid summer? One thing I have found is that sometimes the culprit is impossible to spot! The slightest piece of sand can restrict the pilot jet, so passage of a fine wire through it is recommended. Same with the other small passages. Vacume leaks are possible, even through the crankshaft seals, even yet a restriction in the tank or needle flow could lean it out. If you are satisfied with the fuel flow to the carb, and a triple ck has revealed nothing, a carb swap and even closer inspection for vacume leaks may be neccessary. And yes, I am pretty they use alcohol induced fuel all the time, same as here. Should be 10% or less. MC Quote Link to comment Share on other sites More sharing options...
zippy Posted August 8, 2009 Report Share Posted August 8, 2009 copemech Posted Yesterday, 11:34 PMAnd yes, I am pretty they use alcohol induced fuel all the time, same as here. Should be 10% or less. OH sure, I am not allowed to have alcohol and then drive, but my truck and bikes can have alcohol!!! That's just not fair!! Quote Link to comment Share on other sites More sharing options...
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