Boggy Starts


New Member
Local time
12:19 PM
Aug 23, 2008
Lancaster, CA
I've been running smooth as butter for close to 200 miles now except for a small hiccup I've encountered lately. When I start the engine it runs for a moment and then bogs way down to a sputter. If I pull in the clutch it dies, if I give it gas is does nothing. If I pedal with no throttle, and the clutch let out it runs all bogged out for like 20 seconds and then starts to grab a few times and then slowly comes to life and I'm fine. It takes like 2 or 3 minutes to get all my power back though. I know that this sounds like textbook flooded condition. I checked the float and the float arm. Everything is sound. When I turn off the engine, I always shut off the petcock on the gas tank. There is a bubble in my fuel line that never moves while it sits. I'm pretty sure there is no fuel trickling into the carb during downtime. I have my needle set to the factory second from the top setting which should be pretty lean. I've also noticed lately that on my top end I max out at a lower speed, though it has been MUCH smoother since. WOT only gets my like 28, while I used to be able to get up above 30 before the vibration would make me back off. I actually prefer the smoother lower top end but I worry that the flooding and the weird top end change are related. Thanks for any help anyone can offer.
you might want to adjust the idle pin. i used to have mine set at a high idle and would fire up and run awesome. then i lowered it to have a higher mpg ratio, this made it harder to start and a slightly lower top speed..

hope this helps
200 it's nearly run-in or nearly run-in.
To me it sounds like your running the engine too lean.....why not try lowering the needle clip(thereby raising the needle) so the engine runs richer.
Confirm this by running the engine warm with no choke & then applying the choke PROGRESSIVELY....does it run better as the choke is increased?
I tried gradually increasing the choke and it got slower every time I choked it a little more. I think there's a possibility that the little "c" washer in my throttle assembly might be in the wrong place. I just read a thread about it and I think mine is in there wrong. That might be part of the problem. I hear people say that their idle screw affects their top end but mine doesn't seem to. I can hear the idle pick up and down but it doesn't affect any other aspect of performance. I haven't really got much to complain about. I haven't had a bogged out event again since I first posted. I also read that for the 70cc engines, 6K RPM is about as high as it likes to run for any period of time. If that's the case, going over 30 was over reving anyway. I'm running a 44T sprocket with no plans to upgrade so I'm guessing 26-28 is about as fast as I should expect to go. These eBay guys over estimate the top end on these things BIG TIME. I guess I should have done the math huh.
All the idle screw does is raise or lower the slide when in the rest position, so it certainly shouldn't have any effect on top end. I've read the statements in here too... and just wonder if the idle screw position to top end correlation is imagination or what? It sure should be.

Did you check the simple things first? Theres a screen filter in the shutoff valve at the bottom of the tank, get rid of that and put an inlne filter in. If you did not not clean out the tank when it was new thats probably all it is. Mac
I did clean out the fuel tank, and actually to BGF's credit, it was pretty sparkling clean when I got it. I checked the fuel inlet in the carb too. Didn't seem to have any particles stuck in it. I'm thinking I might need to bend the float arm just a bit. After I'm warmed up it runs greats. I think if I choke it out when I first start it should empty the cup a little quicker and I might not bog out. I'm not sure. It's amazing how simple these 2-strokes are and how many little complications can come up. Thanks to everyones suggestions. I learn a little from all the posts.