Engine trouble with GMS .76
07-30-2010 | 07:23 AM
#1
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From: Branford,
CT
Engine trouble with GMS .76
Hi everyone.. I recently finished my Pulse 60 project and without the front cowling on, I was able to start the engine and it ran for about 20 minutes..
I had some fuel leaks fromexhaustmanifoldand maybe where the glow plug goes in and also the engine was too far back to fit the cowling correctly.
it sat for a month or so.. I received new motor mounts which I drilled correctly and then mounted the cowling and added the exhaust with new gasket.
The problem is that it seems like it is getting fuel.. Its seems like the glow plug is working correctly (tested outside of plane).. but it wont start..
Maybe if I hold a finger over the exhaust it may start for a second but towards the end it was having problems even doing that..
I rtv'd the exhaust and where the carb hooks up to eliminate air leaks..
just not sure what I should do next..
It seems to have compression and the piston seems to go up and down correctly..
I just cant figure out why it ran for a while before and just wont fire up now..
I will make a video of this and post it this weekend but if anyone has any ideas why it won't start, I would appreciate it.
Thanks.
Hairless Hippy.
Watch the unboxing video here:
[youtube]v=8omIdi-_6jw[/youtube]
I had some fuel leaks fromexhaustmanifoldand maybe where the glow plug goes in and also the engine was too far back to fit the cowling correctly.
it sat for a month or so.. I received new motor mounts which I drilled correctly and then mounted the cowling and added the exhaust with new gasket.
The problem is that it seems like it is getting fuel.. Its seems like the glow plug is working correctly (tested outside of plane).. but it wont start..
Maybe if I hold a finger over the exhaust it may start for a second but towards the end it was having problems even doing that..
I rtv'd the exhaust and where the carb hooks up to eliminate air leaks..
just not sure what I should do next..
It seems to have compression and the piston seems to go up and down correctly..
I just cant figure out why it ran for a while before and just wont fire up now..
I will make a video of this and post it this weekend but if anyone has any ideas why it won't start, I would appreciate it.
Thanks.
Hairless Hippy.
Watch the unboxing video here:
[youtube]v=8omIdi-_6jw[/youtube]
07-30-2010 | 09:21 AM
#2
RE: Engine trouble with GMS .76
I have similar issues with my GMS-47. When it runs, it runs beautifully, but some days I have been unable to get it running at all.
What I finally seem to have found, is that the low speed needle valve has a mind of its own. Whenever I am at the point that it won't run, I look at the LSN and it is WAY too rich. I screw it back in to the factory setting (2mm? I think), and it goes right back to running great. I don't know why it is backing itself out, there is plenty of tension on the screw, but I do find that at the setting called for in the manual, the thing runs like a champ.
You may want to check your LSN valve, and lean it out a bit (or a lot).
Good luck
PS - The other problem I had with the engine was the muffler bolts kept coming loose. I ended up putting on longer bolts with nuts on the outside of the muffler, and used red silicone to seal up the flange as well as the muffler segments and pressure nipple.
What I finally seem to have found, is that the low speed needle valve has a mind of its own. Whenever I am at the point that it won't run, I look at the LSN and it is WAY too rich. I screw it back in to the factory setting (2mm? I think), and it goes right back to running great. I don't know why it is backing itself out, there is plenty of tension on the screw, but I do find that at the setting called for in the manual, the thing runs like a champ.
You may want to check your LSN valve, and lean it out a bit (or a lot).
Good luck
PS - The other problem I had with the engine was the muffler bolts kept coming loose. I ended up putting on longer bolts with nuts on the outside of the muffler, and used red silicone to seal up the flange as well as the muffler segments and pressure nipple.
