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Post by joenson on Jun 15, 2015 12:56:14 GMT -6
Hi there. I've got a weird thing happening that I was hoping you guys could help me solve. I made new dragpipes for my bike and had to rejet my carbs - again.. when I had the carbs of, I decided to renew the airmixture screws/O-rings/springs and the floatbowl gaskets. No problems there at all. BUT when I started the engine and warmed it up, i noticed this "popping" sound at idle speed - only on the right side cylinder. Thought that it maybe was a question of adjustment of the airmixture screw, but no matter how I adjust it, the popping just goes on. Also, at cruising speed, the engine doesn't run smooth.. It's like a kind of stuttering. But as soon I accellerate it feels well and smooth. Made a recording, so you guys can listen to it: Anyone have an idea of what it could be.?
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Post by Blaine on Jun 15, 2015 14:07:54 GMT -6
When was the valves adjusted last.......What do you mean......Made diaphrams??
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Post by joenson on Jun 16, 2015 0:05:35 GMT -6
Well.. I'm quite sure that the valves could need an adjustment, but I don't think that it is the problem, since the popping wasn't there until I changed the mixture screws.. The diaphragms?: Yep - I bought new ones, but I didn't change them yet, as the freezer trick worked fine and they both fitted well after being in the freezer for about 1/2 hour. BUT - I have been wondering if there could be a tear in the right side diaphragm that I haven't noticed. Could that cause that kind of behaviour.?
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Post by Blaine on Jun 16, 2015 5:30:12 GMT -6
Well.. I'm quite sure that the valves could need an adjustment, but I don't think that it is the problem, since the popping wasn't there until I changed the mixture screws.. The diaphragms?: Yep - I bought new ones, but I didn't change them yet, as the freezer trick worked fine and they both fitted well after being in the freezer for about 1/2 hour. BUT - I have been wondering if there could be a tear in the right side diaphragm that I haven't noticed. Could that cause that kind of behaviour.? Yes it could because you would have a vacuum leak.
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Post by joenson on Jun 16, 2015 8:22:47 GMT -6
Right then... Guess I'll have to change the diaphragms. A good thing that I have bought new ones.
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Post by joenson on Aug 17, 2015 18:44:20 GMT -6
Well.. Here's the latest: It's been a while. Had 3 weeks road trip in the US ( sadly in a car ). GREAT vacation ! I took of my carbs to locate the problem, and found out that the O-ring for the airmixture screw on the right side carb wasn't seated proberly. Once I had it in place, the popping was gone. Great! I couldn't find any tear or hole in any of the diaphragms - so I didn't change them this time. But maybe I should have, 'cause the "stuttering" is still there. It's most noticeable around 45-50 mph. Nothing at slow city-cruising, and also nothing above 55 mph. How can it be ? I don't know a whole lot about carbs, but could it be that I need to go up one size in pilot-jets? Or maybe get new slide springs ?
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Post by Blaine on Aug 17, 2015 18:49:43 GMT -6
Well.. Here's the latest: It's been a while. Had 3 weeks road trip in the US ( sadly in a car ). GREAT vacation ! I took of my carbs to locate the problem, and found out that the O-ring for the airmixture screw on the right side carb wasn't seated proberly. Once I had it in place, the popping was gone. Great! I couldn't find any tear or hole in any of the diaphragms - so I didn't change them this time. But maybe I should have, 'cause the "stuttering" is still there. It's most noticeable around 45-50 mph. Nothing at slow city-cruising, and also nothing above 55 mph. How can it be ? I don't know a whole lot about carbs, but could it be that I need to go up one size in the pilot-jet? Or maybe get new slide springs ? Pilot jet only affects idle to 1/3 throttle.......Be sure slides are moving smoothly & you should hear vacuum when you push them u by hand,
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Post by eaglerider on Aug 18, 2015 14:44:25 GMT -6
This engine requires periodic valve adjustments (about every 5000 miles) as the valve tend to tighten up. Mal-adjusted valves have a whole lot to do with how well (or not at all) the bike runs. If you don't know when the last adjustment was done, or if it has been a long time, you need to check the adjustment, and adjust them...use the higher value given to adjust them, then before you re-assemble, check the adjustment to make sure it is right.
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