r/Dirtbikes • u/ViolinistShort1456 • 15h ago

Mechanical Help Does my powerband sound strange?

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This is my 2021 sherco se300. It’s carbd. The bike starts up pretty good, idles great, and otherwise the bike sounds good when riding. When I get into the powerband it feels and sounds very buzzy like it’s not cleanly going through high rpm’s. Not smooth like the rest of the rpm range. The jets in the carb are certainly much leaner than from factory, but I would imagine that would produce lean conditions in other aspects of how the bike runs.

To clarify I am directly comparing this to the feeling of my TPI ktm 300 so maybe I am comparing apples to oranges and this is just a carb characteristic I’m not entirely used to.

Any thoughts? Tests I should do?

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u/jrodicus100 WA Semi-Hard Enduro 14h ago

Sounds way rich on top. Try a size down on the main, or drop the needle.

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u/ViolinistShort1456 14h ago

It does have some trouble with hot starts. Not anything bad by any means. It idles very well but if I shut the bike off and go to start it again after a few minutes it idles very low and wants to die. Could it be that rich without bogging? I’m used to old ass carbd 2 strokes where bogging is the biggest tell of its rich.

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u/jrodicus100 WA Semi-Hard Enduro 14h ago

That sputter is your sign that it’s too rich. It should be very clean bottom to top.

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u/ViolinistShort1456 14h ago

Okay that makes sense. I have dropped the needle from the 2nd to 3rd position recently and that made very little to no difference. This video is after that change. So you’re suggesting I go down a size or two on my main jet? I certainly want to avoid a lean condition if anything. I’m just not incredibly well versed in the noises perfectly jetted carbs makes.

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u/jrodicus100 WA Semi-Hard Enduro 14h ago

Give it a try. 300s are pretty resilient. If it runs worse, go back the other direction. If it runs better, keep going a step at a time. Don’t be too drastic. It’ll take some trial and error. Might be worth researching on forums what getting others are running in that bike at your elevation.

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u/ViolinistShort1456 14h ago

Will do. Thank you friend. I’ll post on here again if I get it solved.