SPT5 v3 question regarding turbine splutter.
12-01-2018, 11:57 PM
#1
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SPT5 v3 question regarding turbine splutter.
I have owned this engine for 6 years now and with some small issues along the way decided to have it fully serviced in Germany after a fuel leak started around the gearbox. I have just received my engine back from JetCat Germany and have now had 2 flights and 5 start runs with it. On idle the engine has a splutter and it will continue during acceleration. This is so bad that when opening the throttle from idle to full during flight, that I thought the plane was going to catch fire. I can open the throttle extremely slowly without spluttering, but on idle the splutter remain.
On the ground, with the GSU, I have tried to slow down the acceleration from idle on the ECU, but there is no change in normal operation and flying.
Can anyone give me some help here, because I really don't feel like sending it back to Germany for another 2 month wait and then running the risk of still having a problem?
JanR
On the ground, with the GSU, I have tried to slow down the acceleration from idle on the ECU, but there is no change in normal operation and flying.
Can anyone give me some help here, because I really don't feel like sending it back to Germany for another 2 month wait and then running the risk of still having a problem?
JanR
12-02-2018, 01:23 PM
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Hi Dave,
No I did not send the pump as there were no obvious reason to do so then. The pump has done around 15 hours total time. The engine was originally gas start, but was converted to kero start some years ago. No I did not notice the pump voltage at idle.
Judging by the angle of your questions, it sounds like I should try a new pump?
JanR
No I did not send the pump as there were no obvious reason to do so then. The pump has done around 15 hours total time. The engine was originally gas start, but was converted to kero start some years ago. No I did not notice the pump voltage at idle.
Judging by the angle of your questions, it sounds like I should try a new pump?
JanR
12-02-2018, 10:14 PM
#4
Jan
When we send in turbines for service or repair we always send the pump. On the early type, JetCat check it’s performance and on later Bus turbines they update the software in the pump. I would say 15-20 hours is about it for one of the old brushed pumps, so there is a good chance the pump brushes are pretty worn and dirty. It’s where I would start looking.
Dave
When we send in turbines for service or repair we always send the pump. On the early type, JetCat check it’s performance and on later Bus turbines they update the software in the pump. I would say 15-20 hours is about it for one of the old brushed pumps, so there is a good chance the pump brushes are pretty worn and dirty. It’s where I would start looking.
Dave
12-03-2018, 03:08 AM
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Thanks Dave - I will try a new pump. BUT, I just find it strange that I did not have the splutter issue before. One would expect the pump to be as it was - afterall I did not even touch it during all this time. All I did was to remove the engine and ECU and send to the factory.
Let's hope you are right and a new pump solve my problem - I will let you know.
JanR
Let's hope you are right and a new pump solve my problem - I will let you know.
JanR
12-03-2018, 01:07 PM
#6
Yes, I understand that, but I have seen a pump run perfectly at a 2 day Jet meeting, a week later it did not function at all. The fact yours sat for a while can increase the problem, brushes are worn and then the pump gears are a little clogged with goo, now the brushed motor is too weak for constant smooth flow.
Dave
Dave
12-10-2018, 11:08 PM
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Hi Dave,
Fitted a new pump today and started my engine - no spluttering or popping at all. It certainly sounds promising and I will only know 100% once I have had a fight - but fingers crossed, seems like you've hit the nail-on-the-head.
Cheers,
JanR
Fitted a new pump today and started my engine - no spluttering or popping at all. It certainly sounds promising and I will only know 100% once I have had a fight - but fingers crossed, seems like you've hit the nail-on-the-head.
Cheers,
JanR
03-14-2019, 04:56 PM
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Seems like if that was it that’s great! Sometimes after sitting they get gummed up or tight inside. Brushless would be way better. But only the newest have those and not even all the newest. My spt5 would shut down when I pulled the throttle back fast only part of the time. Changed pumps but to no avail. I nearly cornered it to a deceleration issue.... but having it take 5 seconds to downspool is concerning to say the least.
hope it’s fixed.
hope it’s fixed.
