OS 3500 need advice
09-01-2006 | 11:28 AM
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From: New Port Richey,
FL
OS 3500 need advice
Am waiting for UPS delivery of Giant Aeromaster, and OS 3500 engine. I have no experience w/this engine. (have a LOT of experience w/the large ST engines, and it was all bad). Would appreciate any, and all help/advice on what to expect from the OS 3500. I.E. Best fuel, plug, starting procedures, etc.
Thanks all, Bill
Thanks all, Bill
09-02-2006 | 05:14 AM
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From: STOCKHOLM Akersberga, SWEDEN
RE: OS 3500 need advice
If you run the stock muffler and a 20-24oz fuel tank as near as possible to the engine and big fuel tubings everything should be fine. It has a huge carburetor so if you decide to go aftermarket muffler then make sure the engine is getting enough tank pressure and fuel. Regular fuel with 18-20% oil and 5-15% nitro is fine. On a tuned pipe the power of this engine is really scary[sm=thumbup.gif]
09-02-2006 | 05:14 AM
#4
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RE: OS 3500 need advice
I have a 3500 that I have been using occasionally for eight years. This engine is sensitive to tank placement and to a smaller extent, nitro content. Use the smallest tank you can, I use 16-20oz and make sure its mounted on center with the spraybar. It will run fine on 5% with great fuel economy, BUT the needle setting will change a lot as the tank empties. 15% makes the needle much more steady throughout the flight and during high G maneuvers. Setting the needle is different from smaller engines in that it MUST BE ON THE EDGE OF FOURCYCLING with a full tank!!!! If you lean it beyond that it will get hot and sag in flight. The low speed needle is adjusted for low idle because it is a little rich in the mid range, just keep turning it in until it tries to die out at idle then open it a little. The slow idle will be choppy but is reliable. Starting this engine is super easy, if its cold load it up with fuel and flip it backward, if hot flip forward. Do not flip through compression when cold because it can bite hard. Prop for 7500-8000rpm, it runs out of steam fast above 8000 and looses fuel draw below 7000. It will take 5-10 gallons of fuel before its fully run in.
09-02-2006 | 09:41 AM
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RE: OS 3500 need advice
ORIGINAL: Flyboy Dave
Bill....
....read the manual before you open the discussion to 100 people who
have never really seen one of those engines in real life.
....just a thought. Someone will recommend you get a Saito engine. [X(]
FBD.
Bill....
....read the manual before you open the discussion to 100 people who
have never really seen one of those engines in real life.
....just a thought. Someone will recommend you get a Saito engine. [X(]
FBD.
Oooh! oooh! pick me! pick me!
Mine is on the front of a WM GS P-51. Nice flyer. I installed a 24oz tank an a Cline regulator. I put my Cline on just for security and efficiency. Many install these things thinking it will cure the problems they have when it is actually something else. I run a big Slimline Sportscale muffler which basically looks like a set of Straightpipes coming off the head and straight down. I also hooked up a remote glow-again not to cure a problem but just to have it on their.
09-02-2006 | 10:49 AM
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From: New Port Richey,
FL
RE: OS 3500 need advice
Thanks to all who have replied. The advice should be helpful. I will be mounting the engine on a sport bi-plane, so there won't be much need for 3D performance. (I don't fly 3D anyway). Please keep the advice coming. As they say, "an ounce of prevention, is worth a pound of cure", and I am tired of working on engines @ the field.
09-02-2006 | 01:23 PM
#7
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RE: OS 3500 need advice
Dave is 100% right. Before you listen to what everyone here has to say, see what the people who MADE it say. I would think they know more about their product than anyone else. As we say in the Navy, If all else fails, read the instructions.
09-02-2006 | 01:51 PM
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RE: OS 3500 need advice
One minor thng here is check the headbolts for security when you get it. This is one strong engine, I picked it over the Moki 2.10 when I saw each one in the same type plane as mine. Also seen one inthe Pacific GeeBee Y. Pulls the planes real well.
09-03-2006 | 09:10 AM
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RE: OS 3500 need advice
all i can tell you is that bill baxter recomended an 18 inch prop for 8000 max, no more
i bought one from someone and they ran 15 percent and leaned it out way too early in the break in process, they also took the baffle out of the muff, dont do it! these engines are not made to put out much more than 7500 rpm, mine has slight scoring , but no ring damage
its a brute of an engine, i need a needle valve and a muff, also it will go in a giant scale plane
which is still in the works, i havent run it yet. there are all kinds of schools of thought on this engine, as far as nitro , alot of people say they need high nitro, but its always better to run rich
even with a high nitro content, the manual states only to use 18 percent oil, no mention of nitro.
the other thing is that the manual says max rpm is 10, 000, ITS WRONG!!!
TANK placement is 10 -15 mm below the carb centerline
let me know what you find out
thanks
i bought one from someone and they ran 15 percent and leaned it out way too early in the break in process, they also took the baffle out of the muff, dont do it! these engines are not made to put out much more than 7500 rpm, mine has slight scoring , but no ring damage
its a brute of an engine, i need a needle valve and a muff, also it will go in a giant scale plane
which is still in the works, i havent run it yet. there are all kinds of schools of thought on this engine, as far as nitro , alot of people say they need high nitro, but its always better to run rich
even with a high nitro content, the manual states only to use 18 percent oil, no mention of nitro.
the other thing is that the manual says max rpm is 10, 000, ITS WRONG!!!
TANK placement is 10 -15 mm below the carb centerline
let me know what you find out
thanks
10-06-2006 | 11:28 AM
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From: New Port Richey,
FL
RE: OS 3500 need advice
postscript: Received the aeromaster. It is a great looker, and, flyer. However, the engine was bought from a modeler off of e-bay. The engine was listed as "slightly used" w/one gallon of bench time, and 1 hour in an edge. The engine had no compression, and would not fire. Took the engine apart, and discovered both bearings were shot, the ring was trashed, and the head had a broken cooling fin. plus there was a significant amount of moisture (water) in the engine, w/rust. A local repairman/friend ordered the new parts, and overhauled the engine. It now runs great. I installed it inverted in the aeromaster. The first flight ended in a dead stick. (the muffler vibrated loose). No problem w/the landing. The second flight also resulet in a "dead stick" landing. I finally determined that the engine was about 1 turn too rich. (it was intentional for break in purposes). After leaning out the 1 turn the engine runs like a fine swiss watch, and I am looking forward to a long happy life for the plane/engine.
Moral:: Be VERY careful buying used engines on the internet (or elsewhere).
P.S. The seller (who will remain nameless) refunded the original purchase price, after he was reprted to e-bays fraud dept. and I was only obligated for the cost of repairs, which was close to the original price.
Moral:: Be VERY careful buying used engines on the internet (or elsewhere).
P.S. The seller (who will remain nameless) refunded the original purchase price, after he was reprted to e-bays fraud dept. and I was only obligated for the cost of repairs, which was close to the original price.
10-07-2006 | 12:37 AM
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RE: OS 3500 need advice
ORIGINAL: bill white
postscript: Received the aeromaster. It is a great looker, and, flyer. However, the engine was bought from a modeler off of e-bay. The engine was listed as "slightly used" w/one gallon of bench time, and 1 hour in an edge. The engine had no compression, and would not fire. Took the engine apart, and discovered both bearings were shot, the ring was trashed, and the head had a broken cooling fin. plus there was a significant amount of moisture (water) in the engine, w/rust. A local repairman/friend ordered the new parts, and overhauled the engine. It now runs great. I installed it inverted in the aeromaster. The first flight ended in a dead stick. (the muffler vibrated loose). No problem w/the landing. The second flight also resulet in a "dead stick" landing. I finally determined that the engine was about 1 turn too rich. (it was intentional for break in purposes). After leaning out the 1 turn the engine runs like a fine swiss watch, and I am looking forward to a long happy life for the plane/engine.
Moral:: Be VERY careful buying used engines on the internet (or elsewhere).
P.S. The seller (who will remain nameless) refunded the original purchase price, after he was reprted to e-bays fraud dept. and I was only obligated for the cost of repairs, which was close to the original price.
postscript: Received the aeromaster. It is a great looker, and, flyer. However, the engine was bought from a modeler off of e-bay. The engine was listed as "slightly used" w/one gallon of bench time, and 1 hour in an edge. The engine had no compression, and would not fire. Took the engine apart, and discovered both bearings were shot, the ring was trashed, and the head had a broken cooling fin. plus there was a significant amount of moisture (water) in the engine, w/rust. A local repairman/friend ordered the new parts, and overhauled the engine. It now runs great. I installed it inverted in the aeromaster. The first flight ended in a dead stick. (the muffler vibrated loose). No problem w/the landing. The second flight also resulet in a "dead stick" landing. I finally determined that the engine was about 1 turn too rich. (it was intentional for break in purposes). After leaning out the 1 turn the engine runs like a fine swiss watch, and I am looking forward to a long happy life for the plane/engine.
Moral:: Be VERY careful buying used engines on the internet (or elsewhere).
P.S. The seller (who will remain nameless) refunded the original purchase price, after he was reprted to e-bays fraud dept. and I was only obligated for the cost of repairs, which was close to the original price.
Must have been one powerful gallon of fuel.
