Posted by INTRUDN on August 07, 2001 at 08:00:15:
In Reply to: Re: help please posted by acadia on August 07, 2001 at 06:23:05:
OK, now I'm confused even more. You said that with the gutted stock muffler it ran fine, but then you said that it has no filter at all and the reason you haven't installed one is because you haven't done any riding yet. Were you riding it with the stock muffler and no air filter when you assesed that it was running fine, or was that assesment of it running fine given to you by the previous owner? Doesn't really matter. No air filter equals unrestricted airflow which means you are running V E R Y lean, IF the carb hasn't been rejetted. If your bike was pieced together from several different bikes, then maybe it has been rejetted if it was running fine with a gutted muffler and no airflow restriction through the airbox. Like I said, I'm confused.
Let's say, for the sake of argument, that you have a stock jetted carb. The backfiring and bogging down is normal running for unrestricted exhaust flow and too much airflow into the carb (lean condition). What you will need to do, is decide what kind of air filter you are going to run. Stock paper, or aftermarket foam. The stock filter is more restrictive than the foam, which will give you less airflow through the carb. Whichever you decide, you will still have to "tinker" with the air mixture screw and the idle screw. Once you decide on the type of air filter, it will be easier going from there. Foam filter---remove white spacer, adjust mixture/idle screws and test run. Still runs like crap, rejet, readjust mixture/idle screws, test run again, etc., etc., etc. Stock type filter---leave white spacer in for now, adjust mixture/idle screws and test run. Still runs like crap, remove white spacer and adjust mixture/idle screws, test run again. And by test run, I don't mean running the motor inside the shop. Get on it and put a few miles under the wheels. Living in east Tejas, you are at about the same sea level (central Mizzippi) as I am, and get pretty much the same weather. I am using the stock type air filter on my wife's Savage, pretty much an unrestricted muffler, and the white spacer has been left in. Still backfires every once in a while, but it runs like a scalded dog. I rode it a while back with TobyMS (who was on his 1400 Intruder) and I had it up to 95mph (may not sound like much, but I'm six feet tall and weigh 265lbs) for a few miles before I got worried about the State Troopers coming after me/us.
So, which filter are you going with? Seemed like such a simple project, didn't it? LOL Well, if you can't have fun with it, it isn't worth doing anyway.