ORIGINAL: Aussie Flying
Hi,
I've got two isssues with an OS70 Surpass that I would appreciate advice on:
1. I run on-board glow (activated at 1/4 throttle) using a 1700mah NICD battery. It runs great for about an average couple of flights but then the engine just won't start but the battery has around 1000mah left in it when I recharge it.
How low should I be able to run the battery before I need to recharge?
If I replace with a 3000mah NIMH cell will this work better?
What voltage should I be seeing for the glow to operate correctly?
2. The engine lost a great deal of power so I checked the tappets and found that the exhaust clearance was too small and have adjusted out. Seems to have improved but it is not powering up as much as it should still especially when pulling on the upside of a outside loop. Also I am getting a "burbling" noise when the engine is running at full throttle.
Any ideas on how I can overcome these issues?
Any help here much appreciated,
Simon
Simon,
I'm guessing that you're running no nitro or very low nitro with the problems you're describing. I run my Saito 4-stroke with a similiar setup (except my OBG is on all the time) on 0% nitro. To answers your questions:
1) Since you're OBG cuts off at 1/4 throttle, adding a 3000mah NiMH battery will just gives you more flying time. I agree with the earlier post by loading about your wiring. If too much wire or not properly soldered/connected then the drain on your 1700mah battery may be more than it can handle for a couple of flights. Even if your setup is correct, but your system does not cut off beyond 1/4 throttle then 1700 mah will only give you two to three flights at most. If this is the case, then the 3000 mah will solve your problem. Most standard glow plugs requires a minimum of 1.2v and up to 1.5v. I run a 4500mah NiMH C cell in my setup and it is good for at least five to six 15 min flights (my setup is fairly crude with minimal wires).
2) I get a "burbling" sound at WOT also when my Saito is set up to run rich at the start of a flight. But is it fine for me because it is with a full tank and it sounds fine after serveral minutes when the tank empties a bit and leans it out.
With the loss of power, I have no clue as to your problem.
Please let us know what you did to resolve your problems.
Good Luck.
Fly and be
