polini thor 250 engine

[KOTSMIX]

Hi guys, the axis play matter has been solved, so I'm going for my next questions.

1. What settings do you use for your thor 250 ? Main jet -low jet-needle position.

2. Has anyone got an EGT sensor? I have and I want to get the data if someone is using one.Polini says EGT should normal show 500-620 max650, but as I see from ground running at take off ( Full rpm 7500)I should get readings above max. Your information will be very usefull for me. Thank you, Costas.

[morgy]

Hi

Is your machine standard? Why do you need to change the factory settings? Is your machine converted to a 250 from a 200?

Do you have the New style carb or the older style PWK28.....

Make sure you know what carb you have before taking any advice from other owners about jet sizes....

[KOTSMIX]

Hi, my thor 250 is installed on a one seat flexwing trike. It is an aircreation configuration with a little different cooling system. They use main jet 124, slow 45, and needle 2nd notch from top.Polini standard is main 126 slow 45 and needle 3rd notch.I had my first flight today with same setting with air creation but middle (3rd) notch for needle. The carburetor was the new one but it seemed to have problems with air creation trikes so polini requested return of all new carburators and sent to the customers the old ones.So now I have the old one.My trike is homemade and the wing is the fun 14 and propeller Helix 150cm.I just wanted to know some of your settings and how they work.My concern is most for EGT readings.The standard readings indicated by polini 500-620, 650 max must refer to PPG which are generaly low weight applications. My trike empty weight is 76KG(without fuel).I have cruise speed at 6000-6150 RPM.I can't get any information from air creation beacause the don't use EGT sensor only water temp.So any information will be helpfull.

[morgy]

Hi

The 130 45 is for the new carb, rear overflow goes up. Old style overflow goes out straight...

I have the old style carb, when i got mine it had a 128 and was on the 3 drop on the needle... this was running in setting and run a little Lumpy mid range...

I now have 126/45 2nd drop on the needle... Perfect temps perfect running

I wouldn't bother using EGT for the 250 if your going to use Polini baseline figures for EGT readings.. You need to do a plug chop.

Max water temp should be 90c...

[KOTSMIX]

Hi morgy, thanks for the information. Can you please tell me what spark plug are you using and also the spark plug gap ?

[ifunpixel]

I have this engine on an Air Creation iFun pixel. This uses the iFun 13

wing on a solo trike.

I was asked to return the initial carb after a few months and the

replacement came with a main 130, slow 45 and needle 277 set at the second

notch down from the top. I thought both carbs were the PWK 28, certainly

the replacement one is since it says so on it. The fuel overflow pipes are

slightly different however.

The radiator is the Air Creation set up, below the engine. I have found no

obvious difference between the two carbs, the earlier one having a Polini

main jet 124.

The egt (mgl) sensor is positioned close to the manifold and reads about

560 to 580 generally. Over the winter I have blanked off about 2/3rds of

the radiator.

The coolant temp is mostly about 70 degrees, and never as high as 90 though

at times 80+

On the earlier carb I had lowered the needle to the top notch and the above

readings have been similar in both old and new setup.

I am considering lowering the needle in the new carb, also to the top

notch, on the basis of relatively low egt readings and in the interests of

economy which is disappointing at the moment at closer to 10 than 5 l/h

This is where the egt sensor is useful. If I lean too much then I can spot

any high readings that might risk engine overheating/seizure.

I find that the max rpm is about 670 - once again this has been the same on

both of the carbs aand is lower than I want. Could this be a result of the

prop size?

By and large the engine is smooth above about 4600 rpm and a little lumpy

below this. Pick up is decent enough on accelerating but return to idle is

not too good. I have set the idle rpm to about 1700 to avoid the engine

stopping on tick over on finals. It did stop once when I had perhaps set

the idle a little low.

Hope this is of interest; any suggestions/comments welcome. Basically I am

fairly happy with the engine but would like the max power/rpm to be

greater, given the suggested figures of 7000 to 7500 (presumably improving

the takeoff distance to that suggested by AC),the economy to be better

(nearer to say 6l/h) and the idle to be more consistent.

The engine has about 25 hours on it.

Spark plug supplied was the Champion Copper Plus RN2C though I believe you

can use the NGK BR 10ES also (read this somewhere).

[morgy]

I cant comment on your fuel burn as your on a flex wing trike but 10lph???

I get 8-8.1lph full throttle on my ppg....

I am not sure why your dealer has told you to swap carbs? as far as i was aware the new carbs were just new carbs.. not for a re call or any problems... We have had no unhappy customers with new or old style carbs

If your RPM is only 6700 you have to much Pitch in your prop or your running really rich!!!!

I set my engine to 7500 RPM or MAX Power output not max RPM

put a thermostat in your motor then you do not have to cover the rad...

1700 idle is way to low... 1950-2100 rpm

I fly slow trim at 3800-4000 rpm @ 2lph

5300 rpm @ 3lph

7500 rpm 8lph

[ifunpixel]

Air Creation swapped the plugs because they felt the rpm was more stable in flight!

The prop is not variable pitch so cannot alter that. AC says some of their engines achieve full 7500 rpm, others less though they may 'loosen' with time. Even at 6800 ish it is in the right part of the power curve it is suggested.

I don't feel that the engine is running rich but am aware of the possibility..

Cannot insert a thermostat without purchasing a different water outlet pipe connector on the cylider head because of the arrangement used by AC - easy enough to blank off anyway so I will live with it.

AC suggest an idle rpm 2800ish with clutch engagement 3000-3500. Perhaps my MGL E1 instrument is not reading correctly but mine will idle below 2000 though it doesn't quickly or reliably return to below 2000 after throttling up.

How can I set my max rpm as you imply you do?

Could you tell me what two stroke oil you use and where you get it from please. Presumably fully synthetic!

I am using the champion spark plug supplied - what gap would you use? Or do you considvthe NGK one to be better?

Would be interested in your further info.

[morgy]

Hi

I use Putoline MX9 with the standard champion 2c plus not sure on the gap.. I just use my thumb nail..

We sell Putoline Oil's

sussex paramotors...

I have a ND-D 1.3m prop so ground adjustable... I use this to set for Full power for slalom comps or Higher Pitch to lower RPM's for Eco tasks for classic comps

Sorry i don't Buy into some engine run higher RPM's than others sounds like Dealer BS to me!!! unless you live at altitude.

7500rpm is not MAX RPM!! thats max power on the Curve...

I can't comment on why AC would want or recommend having an idle at 3000-3300rpm. Normal idle is around 2000-2250rpm and should return without hunting or prolonged high rpms then dropping... This tells me your setting is wrong...