Hi Oliver.

I did some more testing today, and now I am very glad I did not just wrap it up and sent it to JetCat.

Since, trying a different pump, force feeding the header tank with a fueling station or feeding the pump directly from a BVM overflow tank with 6mm lines did not help jack sh**, I had a very good gut feeling that my problems was on the pressure side of the pump.

Started the the day by running it in the bench. Same setup as before, only now with the Merlin fuel valve I had lying around.
The result was that it now hit 112k at pv 6,0 for the first time, just as Carsten in DK says his p200sx does. The only difference from the previous attemts is the different type of fuel valve.
With the stock small JetCat valve we only got 109-110k @ pv 6,2 remember...?

The the curiousity hit me, and I wanted to find out if the new valve still was restricting a bit.... I made a by-pass of the fuel valve with two Y's, a piece of 4mm tubing and a ball valve, so when the ball valve is opened, the fuel flow also can go around the electronic fuel valve.
Fired it up again in the bench and went to full throttle. The result with the ball valve shut is 112k @ 6,0 pv. Lowered the throttle a bit and opened the ball valve, then went back to full throttle again. Now the pump voltage droped to pv 5,8. We did this back and forward many times to confirm the results and the same thing hapened every time. In other words, when the fuel also was let around the electronic solenoid, the pump voltage dropped by 0,2 volts.

Then next step was to mount the whole thing back in the plane. I wanted to ensure that the engine performed the same installed in the plane with the whole fuel system connected.
I also made a by-pass system with a ball valve placed just beside the engine to do the test in the same way as we did in the bench.

Fired it up and anxiously pushed the throttle stick forward. I got 112K @ pv 6,0 with the by-pass closed. With the by-pass opened, we got 112k @ pv 5,8 wich is excatly the same values as in the bench. This makes me really satisfied about the planes fuel system.
Again we did this many times to confirm the results, again they vere the same every time. pv 6,0 with only the electronic valve and the by-pass closed, and pv 5,8 with the by-pass opened.

So. The restriction was fuel solenoid all along. The sad part is that it was the single last piece in the entire fuel system that we checked and eliminated as a cause, and that I have spent many, many hours on this issue. Partly bacause so many was so certan that the problem was on the suction side.
I have had a bad feeling about theese small valves and the small pump on such a large engine from the moment I opened the box.

I still don't think it's right of JetCat delivering theese engines with fuel valves and fuel fumps that are so close to the limit on what they can perform.
The pump is running at almost 100% of it's capacity and the nipples on the fuel valves are only 1,5 mm ID. Don't know the ID of the fuel valve it self, but probably even smaller.
When things are running so close to it's limits in a pefrect world, it does not take much of a problem (restriction) before the engine does not get the fuel it needs to reach max rpm.

In my case it was the fuel valve that was the tiny restriction. If it was only my valve, I don't know for sure, but my faulty valve would work great in a P-60 to a P180 and the owners of theese engines would never know they had a bad valve. But in a P200SX the restriction was just a little too much...

One thing is for sure: JetCat has not run my engine with my ECU or with my fuel valves! I also seriously doubt they have run the pump either.
The ECU showed zero runs and running time. The valves vas very dry a new in their bag with no traces of kero.

My guess is that they have a bench set up with valves and pump and ECU so they just drop the engine in and making sure that it runs OK.
Probably saves them a few minutes not having to rig up each set up with ECU, wireing and plumbing of valves, pump etc. and then taking it all appart and unplumb it and dry everything before packing.
Much easier to just drop a engine down in the bench and go.
Well. Had they bothered to do so, I would not have waisted all this time, and that kind of pis*** me off that they leave the testing of the external equipment to the end user.
I have paid a lot of money for this biggest engine in the JetCat range and they did not even bother to test it properly before shipping it out.

Judging from the PM's I have gotten, I am not alone thinking that the supplied valves and pump is (barely) up to the job, or not the only having fuel supply related problems with the p200 (sx).
Maybe something is changed inside the 200sx compared to the old 200 making the fuel pressure higher and the job tougher pr the pump??? Different injectors and or combustion chamber maybe??

What will I do next?
1: I will ask for a new valve by JetCat. With my luck I'll probably have in a year or so.
2: Since getting a fuel valve from JetCat that IMO is up to the job (with a margin) is probably out of the question, I will find one my self.
3: I will talk to Peter Hausl and find a pump that delivers a little more, say 20% more so the max pump voltage is in the 4,5 to 5,0 volt range, giving a better margin.
4: Next time I will give more faith to my gut feeling. Had I done so this time, it would have saved me a lot of hours in the work shop, headache and a lot of words I can't even spell
5: Don't listen to arguments like "JetCat would not deliver it if it was not OK" and "Don't think so much and just go out and fly" and " It's best because uncle Bob says so"

Some pic to prove I'm not just lying


The by-pass and the fuel valve from the Merlin engine


Running in the plane with by-pass closed @ 112k @ pv 6,0


Running in the plane with by-pass open @ 112k @ pv 5,8


The by-pass valve is placed beside the engine. I will remove the by-pass system when I get a pump and valves that is up to the job.


Too cold outside so we ran it from the inside of the workshop with the door open and just the tailcone sticking out.
-18c outside and +20c inside[8D]