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SureStart Questions

Old 02-07-2008, 04:29 PM
  #1  
smoknDave
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Default SureStart Questions

Hi all!,

I've recently decided to do something with one of the SureStarts I've purchased. I ran the engine on a test stand and was surprised at how easily it started and how strong it ran. So, just to play, I built a pylon for an old Gentle Lady glider. I rotated the backplate so that the cylinder is 180 degrees from the needle valve/choke tube assembly, and mounted the engine with the cylinder pointing to the left and needel valve to the right. Now the engine won't run past the primer[] I believe its not drawing fuel due to an airleak. I've checked the fuel line and will dismantle and clean the engine tonight (making sure to check the o-ring and crank gasket). My questions are, is it okay to rotate the backplate to put the cylinder and needle valve/choke tube assembly where I want them? And, can I use RTV as a gasket sealer between the crank case and backplate or will fuel attack it?

Thanks!

Dave
Old 02-07-2008, 08:03 PM
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dieFluggeister
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Default RE: SureStart Questions

The plane should run equally well regardless of the orientation of the backplate. I have used RTV gasket maker for a carb gasket without ill effects. I think these 1/2A gurus use a paper of sorts to actually make a gasket. Can you guys lend a hand?
Old 02-07-2008, 10:33 PM
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lildiesel
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Default RE: SureStart Questions

I haven't been able to get paper thin gasket material at the local autoparts stores in ages. These days I'll use thin sheet Teflon to make gaskets for Cox .049s when I need some. It was never hard to make a gasket way back when: the only really important accurate cut is the 1/2 inch hole which I did with a sharpened piece of brass tubing. Cut a 1" square around the hole and mark it with pin*****s for the tank/backplate screws and use a 1/6th bit in a pin vise to make the holes. Not pretty but it works. And if you're fussy, nail scissors can be used to trim things up when the case and backplate are screwed together.
Old 02-08-2008, 07:08 AM
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gcb
 
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Default RE: SureStart Questions

Dave,

Since it ran fine before you reversed the cylinder, I would guess that the problem is a leak between the backplate and the crankcase.

Check that the rear of the crankcase is flat. Some have not been.

Next, check that there is no grit, cuts, dents, etc. on the existing gasket. You should not need gasket sealer unless the gasket is damaged and you don't want to make/locate another.

Also, when tightening screws, just snug them up until all are in place, then tighten. Preferably tighten one, then the one across from it.

Good luck with it.

George
Old 02-08-2008, 07:58 AM
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flyinrog
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Default RE: SureStart Questions

Umm, any particular reason you cant put it back like it was..??
Old 02-08-2008, 08:24 AM
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Andrew
 
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Default RE: SureStart Questions

When you rotated the backplate, did you remove the choke tube to mount it? Two things can occur. The backplate screws may bottom out in the crankcase before the backplate tightens up -- the choketube adds enough thickness to keep this from happening. Secondly, when mounted flat without a choketube, some of the air intakes will be blocked due to molding flash and not allow airflow into the venturi. You can either Dremel a groove in the firewall to improve airflow or use an Xacto knife to cut away some of the flashing.

Like George said, check the back of the crankcase -- I've found many of the screw holes will have a shoulder from tapping. The case back can be smoothed up by light lapping with oil on a piece of 400 or 600 grit paped placed flat on a piece of glass.

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