UMS Evolution Radial Care and Operation
06-06-2014, 01:08 PM
#1151
Join Date: May 2007
Location: Teague,
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10% of 128 is 12.8.......13 off of 128 is 115......so 10 % oil will be 13 ozs of oil in 115 ozs of methanol.
06-17-2014, 03:52 AM
#1152
Join Date: Mar 2006
Location: East Aurora,
NY
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I have finally started and flown mu UMS 9-99 in my 87 inch Ziroli Stearman. Using fuel which is 7.5 % oil and 7.5% nitro. Prop is Xoar 24X12. On board glow McDaniels.. Engine starts easily with electric starter. After 4 runs totaling about 45 minutes engine idles solidly at 1500-1800 rpm. At wide open throttle I am peaking at 4500-4700 rpm. Model weighs 29 pounds with 18 oz ballast in tail. First flight , model lifted off of high grass in 50 feet in shallow climb..At altitude of 100 feet still in shallow climb the engine quit. Landed in ditch off field damaging all four wings, prop and fuse intact. Inspection after crash revealed engine would quit when nose held up at 45 degree angle. Further inspection revealed tach I was using (Fromeco) was giving misleading readings until battery was changed. I reset the needle to provide 4500 rpm measured with two tachs and engine runs solidly at 45 degree nose up angle. I learned a good lesson. When the tach acts funny even when indicating 3600 rpm against a light bulb. don't trust it. I believe my engine leaned out and quit.
06-23-2014, 12:39 PM
#1154
Join Date: Mar 2006
Location: East Aurora,
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I am having problems with my 9-99. It starts easily, idles very well. On second flight it tached 4000 rpm with a 24X12 prop. It took off in 50 feet, climbed out with authority and flew very well at one half and full throttle. After 5 minutes of flight at about 3/4 throttle the engine quit. Back on the ground it restarted easily. Iam using a 32 oz, tank, it was not empty. Should I be opening the needle more and trying to fly with a ground RPM at about 3800?
06-24-2014, 03:57 AM
#1157
Join Date: May 2007
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06-24-2014, 04:52 AM
#1158
Dad, it is not the easiest to detect. Fill the tank half full of fuel and throttle to mid position. The engine will sound fine, the it will sound "hard" and then begin to slow down. It takes a while for the crankcase to lean out. Avoid that hard sound. It will become clear during careful listening. -Tom
06-24-2014, 10:29 AM
#1159
Join Date: Mar 2006
Location: East Aurora,
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Maxam,
I hope you are contemplating writing a book or instruction manual on the " care and feeding of radial engines and other multicylinders". I can see a market for it in the $25 and up range. My attempts at printing out your posts have been time consuming.
John
I hope you are contemplating writing a book or instruction manual on the " care and feeding of radial engines and other multicylinders". I can see a market for it in the $25 and up range. My attempts at printing out your posts have been time consuming.
John
06-25-2014, 06:06 PM
#1161
My Feedback: (4)
Well just a report,
mixing my own fuel the first batch, I mixed some methanol 64 0z., and 6.4 oz. of klots oil (80% synthetic 20% castor) (I know, I know it was more than half a gallon), no nitro, and tried to run My 7-77, it would run good as long as I kept the glo switch on but as soon as I switched the glo off it would lose power and cylinders, ran terrible would not even throttle back up, so I drained tank, I added 5% nitro, 3oz. and tried again,same results, drained tank and same results would not stay running without the glo on. 2nd batch I made was 1 gal. 128 oz. 108 oz. of methanol, 13oz. 10%, of the klots oil same oil, 7 oz. of nitro 5%,= 128 oz. and got the same results ran good until you turned off the glo switch, then added 7 more oz. of nitro, to this same gallon, with same results, drained tank, now, next test I mixed 12 oz. of my Wildcat fuel (18% oil and 15% nitro) and 12 oz. of methanol only= 24 oz. surprisingly ran a little longer but when the glo switched off after 10 or so seconds lost power again with the same results, now all this testing without messing with the carb adjustments at all, then went back to the original "Ritches Brew " of 9 % oil( straight synthetic) and 5% nitro, and walla ran just beautiful even with the glo switch off, actually got a flight in after all this, now, I could have tried to adjust the carb, but wanted to achieve the same grade or blend to make it run the same as the Ritches brew with the same settings of the carb, so now just wondering if the mixture is missing something or too much oil? or not enough nitro? maybe the methanol is a lower grade than it should be?, or nitro not as good a grade ? not giving up! but will order some more Ritches brew, and, maybe try adjusting the carb on some of these blends just for the fun of it, so testing goes on (: ...............Steve.
mixing my own fuel the first batch, I mixed some methanol 64 0z., and 6.4 oz. of klots oil (80% synthetic 20% castor) (I know, I know it was more than half a gallon), no nitro, and tried to run My 7-77, it would run good as long as I kept the glo switch on but as soon as I switched the glo off it would lose power and cylinders, ran terrible would not even throttle back up, so I drained tank, I added 5% nitro, 3oz. and tried again,same results, drained tank and same results would not stay running without the glo on. 2nd batch I made was 1 gal. 128 oz. 108 oz. of methanol, 13oz. 10%, of the klots oil same oil, 7 oz. of nitro 5%,= 128 oz. and got the same results ran good until you turned off the glo switch, then added 7 more oz. of nitro, to this same gallon, with same results, drained tank, now, next test I mixed 12 oz. of my Wildcat fuel (18% oil and 15% nitro) and 12 oz. of methanol only= 24 oz. surprisingly ran a little longer but when the glo switched off after 10 or so seconds lost power again with the same results, now all this testing without messing with the carb adjustments at all, then went back to the original "Ritches Brew " of 9 % oil( straight synthetic) and 5% nitro, and walla ran just beautiful even with the glo switch off, actually got a flight in after all this, now, I could have tried to adjust the carb, but wanted to achieve the same grade or blend to make it run the same as the Ritches brew with the same settings of the carb, so now just wondering if the mixture is missing something or too much oil? or not enough nitro? maybe the methanol is a lower grade than it should be?, or nitro not as good a grade ? not giving up! but will order some more Ritches brew, and, maybe try adjusting the carb on some of these blends just for the fun of it, so testing goes on (: ...............Steve.
Last edited by slskn; 06-25-2014 at 06:21 PM.
06-28-2014, 02:18 PM
#1169
Join Date: Mar 2006
Location: East Aurora,
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Follow Maxam's dir Their product support is terrificections
I have followed Maxam"s directions to solve problems with my 9-99 quting in the air. They work perfectly. I have found that the Sonic Tronic glo connecters don't mate well with OS F4 plugs. Hard to get on and vibrate loose in flight. Their product support is terrific however and they rapidly solved my problem with scale like connecters. I am close to having a great running very reliable 9-99. I am using Wildcat fuel diluting 132 ounces to 180 ounces with methanol to produce 10oil% and 5.5% nitro.
07-01-2014, 03:32 AM
#1170
My Feedback: (3)
Join Date: Aug 2003
Location: near Innsbruck, AUSTRIA
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Re-maidened my Stearman last weekend. Love the Radial, starts on the second flick at the latest every time. (provided the Glow Driver doesnt act up) 
Love the scale power and speed on my bashed arf aeroworks stearman.
Running it on 10% RAPICON Fuel (18% Oil) thinned out to 9% Oil with pure Methanol.
Love the scale power and speed on my bashed arf aeroworks stearman.
Running it on 10% RAPICON Fuel (18% Oil) thinned out to 9% Oil with pure Methanol.
07-06-2014, 05:23 AM
#1172
Senior Member
Hello again
It's been bad with flying unfortunately
some times have flown with 7-35.
I miss the power and rpm I had before.
With a Gsonic 18x8 prop I get now 6480 rpm.
When I had the pre carburetor so yes got out 7000 + rpm.
it is great a difference these carburetors.
So now to my question, if I read the manual from the horizon of adjustment.
so it will be quite wrong, opening two laps the engine sounds good on the ground but in the air it becomes weak.
I must fly at full throttle almost all the time
You who have a 7-35 talk about how you have adjusted your needles and speed
has 10% nitro and 7% oil.
Maybe try the old carburetor; it was kinda unsure at full throttle (the dog)
'm grateful for all the tips, we keep in touch Lars
It's been bad with flying unfortunately
some times have flown with 7-35.
I miss the power and rpm I had before.
With a Gsonic 18x8 prop I get now 6480 rpm.
When I had the pre carburetor so yes got out 7000 + rpm.
it is great a difference these carburetors.
So now to my question, if I read the manual from the horizon of adjustment.
so it will be quite wrong, opening two laps the engine sounds good on the ground but in the air it becomes weak.
I must fly at full throttle almost all the time
You who have a 7-35 talk about how you have adjusted your needles and speed
has 10% nitro and 7% oil.
Maybe try the old carburetor; it was kinda unsure at full throttle (the dog)
'm grateful for all the tips, we keep in touch Lars
Last edited by Linkan2; 07-06-2014 at 05:26 AM.
07-11-2014, 04:45 PM
#1173
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Lars,
Something to try,
BVM R/C mixture control unit http://shopbvmjets.com/zencart/index...roducts_id=105
I set it up so I am extremely rich on the high setting and then lean the engine for flight conditions. It's stupid expensive but I love it.
Something to try,
BVM R/C mixture control unit http://shopbvmjets.com/zencart/index...roducts_id=105
I set it up so I am extremely rich on the high setting and then lean the engine for flight conditions. It's stupid expensive but I love it.
07-12-2014, 01:12 PM
#1175
Senior Member
Hello again
I must admit one thing about my 7-35.
you who have read my previous posts, so wet you that I have replace the bearing.
when reassembling the engine, I've got the cam wrong (late cam time).
I noticed when I took note of cam time.
intake valve was open when the piston was going up = worse comp.
now i have a good comp on all cylinders.
I will return when I run the engine.
can say that there is no mark for cam adjustment
Lars
I must admit one thing about my 7-35.
you who have read my previous posts, so wet you that I have replace the bearing.
when reassembling the engine, I've got the cam wrong (late cam time).
I noticed when I took note of cam time.
intake valve was open when the piston was going up = worse comp.
now i have a good comp on all cylinders.
I will return when I run the engine.
can say that there is no mark for cam adjustment
Lars