Kolm 135 install in CARF Mustang
02-11-2015, 06:38 AM
#227
No flying today, but I tried different fuel, 98 octan with Mobile premium racing 4 stroke oil (mixed 2%). I have used Stihl Motomix "bio"fuel up until today, it is the fuel I run in my Moki, with great success.
No difference unfortunately.....BUT, it seems like sylinder #2 ( close to firewall) drops out from time to time, so maybe it is an ignition problem?
Sylinder #2 is definately the problem, as it will not go over 75C (45-50C at idle/low rpm). #1 has normal temp (110-130C).
At ca 80% throttle, the rpm is 4000, but when I advance to 100%, the rpm drops to 3800.
Can it be a fuel delivery issue as well? Personally I don't think so, but I need to keep all doors open for solutions..
I have now changed the spark plugs, but they looked ok to me, maybe a bit to black (indication of too rich mixture?)
Lots of questions here....I know... Maybe someone has suggestions of any kind?
Kim
No difference unfortunately.....BUT, it seems like sylinder #2 ( close to firewall) drops out from time to time, so maybe it is an ignition problem?
Sylinder #2 is definately the problem, as it will not go over 75C (45-50C at idle/low rpm). #1 has normal temp (110-130C).
At ca 80% throttle, the rpm is 4000, but when I advance to 100%, the rpm drops to 3800.
Can it be a fuel delivery issue as well? Personally I don't think so, but I need to keep all doors open for solutions..
I have now changed the spark plugs, but they looked ok to me, maybe a bit to black (indication of too rich mixture?)
Lots of questions here....I know... Maybe someone has suggestions of any kind?
Kim
02-11-2015, 10:48 PM
#230
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No flying today, but I tried different fuel, 98 octan with Mobile premium racing 4 stroke oil (mixed 2%). I have used Stihl Motomix "bio"fuel up until today, it is the fuel I run in my Moki, with great success.
No difference unfortunately.....BUT, it seems like sylinder #2 ( close to firewall) drops out from time to time, so maybe it is an ignition problem?
Sylinder #2 is definately the problem, as it will not go over 75C (45-50C at idle/low rpm). #1 has normal temp (110-130C).
At ca 80% throttle, the rpm is 4000, but when I advance to 100%, the rpm drops to 3800.
Can it be a fuel delivery issue as well? Personally I don't think so, but I need to keep all doors open for solutions..
I have now changed the spark plugs, but they looked ok to me, maybe a bit to black (indication of too rich mixture?)
Lots of questions here....I know... Maybe someone has suggestions of any kind?
Kim
No difference unfortunately.....BUT, it seems like sylinder #2 ( close to firewall) drops out from time to time, so maybe it is an ignition problem?
Sylinder #2 is definately the problem, as it will not go over 75C (45-50C at idle/low rpm). #1 has normal temp (110-130C).
At ca 80% throttle, the rpm is 4000, but when I advance to 100%, the rpm drops to 3800.
Can it be a fuel delivery issue as well? Personally I don't think so, but I need to keep all doors open for solutions..
I have now changed the spark plugs, but they looked ok to me, maybe a bit to black (indication of too rich mixture?)
Lots of questions here....I know... Maybe someone has suggestions of any kind?
Kim
Geir
02-11-2015, 10:54 PM
#231
02-12-2015, 04:53 PM
#232
Just for familiarization maybe take a look at the valve clearance and make sure it's to spec as well as the same for both heads. I've seen this from nitro four stroke engines and after the adjustment it goes away.
Afterwards, reset the carb needles and run the engine. See if the cylinder temps come up right and then tweak as needed to stabilize the temps and response. Also the rear cylinder will probably run a little hotter than the front so you might consider that in your tune.
Afterwards, reset the carb needles and run the engine. See if the cylinder temps come up right and then tweak as needed to stabilize the temps and response. Also the rear cylinder will probably run a little hotter than the front so you might consider that in your tune.
Last edited by Chris Nicastro; 02-12-2015 at 04:57 PM.
02-12-2015, 11:07 PM
#233
Just for familiarization maybe take a look at the valve clearance and make sure it's to spec as well as the same for both heads. I've seen this from nitro four stroke engines and after the adjustment it goes away.
Afterwards, reset the carb needles and run the engine. See if the cylinder temps come up right and then tweak as needed to stabilize the temps and response. Also the rear cylinder will probably run a little hotter than the front so you might consider that in your tune.
Afterwards, reset the carb needles and run the engine. See if the cylinder temps come up right and then tweak as needed to stabilize the temps and response. Also the rear cylinder will probably run a little hotter than the front so you might consider that in your tune.
I am WIDE open for solutions, even if it classifies me as a dumb axx
The engine is now off the airframe, and will be mounted on the bench for further testing, after I have cleaned both carbs and checked/adjusted the valves.
I have sent an email to Kolm, eagerly waiting for a response.
Have i nice weekend!
Last edited by kimhey; 02-12-2015 at 11:14 PM.
02-12-2015, 11:48 PM
#234
Sorry to hear but Ive been there on other engines so I know how it feels. It has to be something basic unless there is a flaw in production. Due diligence will tell, take a break and regroup.
I currently have a strange issue with two DLE 35RA's where one runs harder than factory specs and the other is not making enough power. Lol, so Im going to adjust timing etc and try to make them a match, well close enough. Its for a YA P-38 so not much room for error.
I currently have a strange issue with two DLE 35RA's where one runs harder than factory specs and the other is not making enough power. Lol, so Im going to adjust timing etc and try to make them a match, well close enough. Its for a YA P-38 so not much room for error.
Last edited by Chris Nicastro; 02-12-2015 at 11:52 PM.
02-13-2015, 05:59 AM
#235
Kimhey,
This might sound dumb but have you tried flushing out the carburetors to see if maybe there is some blockage in the fuel flow of the carbs.
I had this happen on my Moki and even though it still ran, it made it hard to get it adjusted properly. I have a filter inline to the carburetor now.
It was a piece of plastic flashing the broke off inside the tank from the seam that was sucked thru the fuel line and got trapped in the screen inside the carburetor.
Just something else to check and see.
This might sound dumb but have you tried flushing out the carburetors to see if maybe there is some blockage in the fuel flow of the carbs.
I had this happen on my Moki and even though it still ran, it made it hard to get it adjusted properly. I have a filter inline to the carburetor now.
It was a piece of plastic flashing the broke off inside the tank from the seam that was sucked thru the fuel line and got trapped in the screen inside the carburetor.
Just something else to check and see.
Last edited by Greg Wright; 02-13-2015 at 06:18 AM.
02-13-2015, 06:33 AM
#236
Guys, thank you for support/suggestions!
I checked the valve clearance this morning, and they were all way off.. The manual states 0.1mm, but the were varying from 0.25 to 0.35(+). I adjusted them and this time the engine sounded better
I even got something you can call full power, but not 100% steady. Started to adjust, but then syl#1 started to drop out (low temp on my telemetry screen). I need to sort this out, the spark plugs are new, changed yesterday.
Need more time to trouble shoot, cleaning of the carbs is on the list.
One thing that bothers me, is the eccessive vibration at certain rpms.
Kim
I checked the valve clearance this morning, and they were all way off.. The manual states 0.1mm, but the were varying from 0.25 to 0.35(+). I adjusted them and this time the engine sounded better
I even got something you can call full power, but not 100% steady. Started to adjust, but then syl#1 started to drop out (low temp on my telemetry screen). I need to sort this out, the spark plugs are new, changed yesterday.
Need more time to trouble shoot, cleaning of the carbs is on the list.
One thing that bothers me, is the eccessive vibration at certain rpms.
Kim
02-13-2015, 06:59 AM
#237
Kim Are you using the rubber mounts? I feel for you, I hate engine problems! I bought this mustang solely because of the Kolm engine. For the price, you'd think they would be dialed. The literature says they are broken in at the factory, is this not true? I was planning on setting it up right away to run ideal, not a rich phase or break in phase. I'm a month or so away from the first start, wondering if I should build a bench mount now???
02-13-2015, 08:20 PM
#241
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Kim,
I think you are on the right track with all the support the other guys are offering. I would mention that I did read a thread on the Warbirdforum.de where a customer was having troubles like yours, and turned out the ignition was faulty.
Hans is very busy, but each time I have tried, he will answer emails. Something else Hans mentioned, that they are recommending fuel pumps( just like the one used on the Mokis) resulting in better performance. I haven't tried it yet with my new 150, but I will this spring.
Don't give up, all the Kolms I have start so easy, and run super strong.
Regards,
John
I think you are on the right track with all the support the other guys are offering. I would mention that I did read a thread on the Warbirdforum.de where a customer was having troubles like yours, and turned out the ignition was faulty.
Hans is very busy, but each time I have tried, he will answer emails. Something else Hans mentioned, that they are recommending fuel pumps( just like the one used on the Mokis) resulting in better performance. I haven't tried it yet with my new 150, but I will this spring.
Don't give up, all the Kolms I have start so easy, and run super strong.
Regards,
John
02-15-2015, 05:04 AM
#243
SUCCESS! I sent an email to Kolm on friday, hoping for a reply next week. Silly me...Hans answers even on saturday evening, and he quickly suggested that the Hall senor was slightly misaligned. As that was allready installed when I got the engine, I did not pay any attention to it when trouble shooting.... Learning is a never ending thing
Anyhow, I started the enginge today, after adjusting the Hall sensor 1mm (!) forward, and....."Engine sound nirvana" unleashed when I cranked the thing. Got a steady top rpm (5400 with a 28x14) and the vibration was gone. This is static of course, but as camparison, I have flow 4 flights with only some 4000 rpm 13kg/28Lbs of static thrust (more than enough or scale flying), but at 5400 I will get somewhere around 23kg/52Lbs of static trust.
With the Fiala 30x14 which will be mounted for flying I will get even more..
AUW is 19.5kg/43Lbs, so the performance will be great!
Great support from Kolm Engines, and my engine will mounted to my Carf spitfire again very soon.
Kim
Anyhow, I started the enginge today, after adjusting the Hall sensor 1mm (!) forward, and....."Engine sound nirvana" unleashed when I cranked the thing. Got a steady top rpm (5400 with a 28x14) and the vibration was gone. This is static of course, but as camparison, I have flow 4 flights with only some 4000 rpm 13kg/28Lbs of static thrust (more than enough or scale flying), but at 5400 I will get somewhere around 23kg/52Lbs of static trust.
With the Fiala 30x14 which will be mounted for flying I will get even more..
AUW is 19.5kg/43Lbs, so the performance will be great!
Great support from Kolm Engines, and my engine will mounted to my Carf spitfire again very soon.
Kim
02-21-2015, 08:01 AM
#245
Finally real testing!
First takeoff with 30x14 prop, but nose over and I think it was wise to change prop. I had a spare 28X14 in the car luckilly
https://www.youtube.com/watch?v=RaUO5961kuE
First takeoff with 30x14 prop, but nose over and I think it was wise to change prop. I had a spare 28X14 in the car luckilly
https://www.youtube.com/watch?v=RaUO5961kuE
02-21-2015, 01:22 PM
#248
Needles factory set, but 1/8th turn in on both H needles. The 28x14 prop reached 5400 static, 6350 at wide open throttle lowpass.
Temps were exellent, maxed at 118C on #1, and 116C on #2. Both sylinder temps followed each other with minor differences.
Temps were exellent, maxed at 118C on #1, and 116C on #2. Both sylinder temps followed each other with minor differences.