LEO .46 Will not run.

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I have a Leo .46 that will not run due I believe to fuel starvation.

On the bench it will run with the fuel tank pressurised and elevated about 300mm but in the model it will only idle. Restricting the exhaust and thus applying additional pressure to the tank, will breathe life into it but it runs very hot.

The fuel lines are clean and clear, and the needle seems unrestricted. I have checked the carbi and can see no obvious issue but I note that instead of a jet there is a slot. I am not familiar with this set up - it looks a though as the throttle barrel rotates and moves out more of the slot opens up increasing fuel flow? Probaby really good when it works. Sadly, in this case it does not.

Has anyone experience with this issue?

Peter

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Peter Ab Members Profile Send Private Message Find Members Posts Add to Buddy List Gold (AU) USERID: 881858 Newbie Joined: 29/Dec/2011 Online Status: Offline Posts: 3	Quote Reply Topic: LEO .46 Will not run. Posted: 29/Dec/2011 at 11:21am
	I have a Leo .46 that will not run due I believe to fuel starvation. On the bench it will run with the fuel tank pressurised and elevated about 300mm but in the model it will only idle. Restricting the exhaust and thus applying additional pressure to the tank, will breathe life into it but it runs very hot. The fuel lines are clean and clear, and the needle seems unrestricted. I have checked the carbi and can see no obvious issue but I note that instead of a jet there is a slot. I am not familiar with this set up - it looks a though as the throttle barrel rotates and moves out more of the slot opens up increasing fuel flow? Probaby really good when it works. Sadly, in this case it does not. Has anyone experience with this issue? Peter

airwave Members Profile Send Private Message Find Members Posts Add to Buddy List Retail (US) USERID: 71296 Hobbyking Addict Joined: 27/Aug/2009 Online Status: Offline Posts: 2739	Quote Reply Posted: 30/Dec/2011 at 1:06pm
	looked but can,t find much on this.dont have this type motor but would check the seal on carb to motor allso. you should be able to make it smoke and 4 cycle if it is a two stroke by adjusting the richness screw. would say air is getting in some were. the heat comes from a to lean mix.

Peter Ab Members Profile Send Private Message Find Members Posts Add to Buddy List Gold (AU) USERID: 881858 Newbie Joined: 29/Dec/2011 Online Status: Offline Posts: 3	Quote Reply Posted: 30/Dec/2011 at 2:03pm
	Yes I have applied engine oil to the outside of the carbi mount and the richnes screw looking for air leaks and have found none. The symptoms all point to fuel starvation and with the richness wound right out it is still lean. My prognosis is that the jet is too small but as I mentioned it is not a hole I can drill out - it is this funky slot thing. I suspect the slot is too narrow / short but without a specification and no experience it is a difficult one. Thanks for the input and any other suggestinos most welcome.

rcmodelreviews. Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Platinum (NZ) USERID: 4042 HobbyKing aficionado Joined: 06/Mar/2009 Location: New Zealand Online Status: Offline Posts: 1978	Quote Reply Posted: 30/Dec/2011 at 2:34pm
	Make sure the low-speed needle is not wound too far in and that you've got the main needle opened to about 2 or 2.5 turns from fully closed. Check that the pressure nipple on the muffler isn't blocked (sometimes they're not properly drilled). Check also that the backplate and head screws are tight.
	RcModelReviews

Peter Ab Members Profile Send Private Message Find Members Posts Add to Buddy List Gold (AU) USERID: 881858 Newbie Joined: 29/Dec/2011 Online Status: Offline Posts: 3	Quote Reply Posted: 04/Jan/2012 at 4:15pm
	I tightened back plate bolts and found a few that took a quater of a turn so removed cleaned and reseated the back plate. I also backed off the idle richness and that improved its perfornace cnsiderably on the bench. It will still not four stroke without elevating the tank but will run smokey and cool. I will try it in the air this weekend and report back on its performance. Well done and thanks for your assistance. Peter