heli-john

I'd had lots of trouble getting it to start - Raptor V2 with TT Pro 39 - but finally it seemed to be doing OK. Bit iffy on needle settings but basically hovered nicely in the back yard. It is a ARTF kit I'd bought from a chap last year who hadn't been able to assemble it so all new. The motor is a pain and I know people say junk it but it was new and an OS don't come cheap. I finally got it running, then had a gyro problem which got sorted in the backyard and put it away for months waiting for a time like now.


After not messing with it for months I took it to the farm I use and it fired up fairly well. First time with it on the wide open space. Kept it low as it is the first flight and put it on the ground.
Problem is it just cut out when on the ground. For the first few minutes it is fine. I didn't want to be too adventurous as it is the first time out on the field with it but I put it on the ground after say 5 mins of settling in and it cut. It then started to cut before I could take it to my flying area.

I will admit one time it cut because the glow plug came out. So embarrassing. Even after a not doing anything with it for a while I did expect to get a tank of flight out of it this time.

I think it was hot but can't say it was running weak particularly. So what's up with it? I'd love an OS but can't outlay that sort of money now. Anyway, it fires up nicely and runs ok............for a while. I know it smacks of needle adjustment but I can't get it to react differently even after a needle twiddle. It just cuts.

ATVAlliance

Sounds like its in your low end.

Or if it starts, idles, revs up to full and back down again to idle when you first start it...then after a while you start to see these symptoms, it could be a heat issue and introducing a leak or low compression.

Could be as simple as a glo plug too.

Im not that up on nitro engine tuning...I can do it somewhat, but still always ask for more experienced peoples help at the field to "fine tune" my tune.

Im sure some nitro guys will chime in here soon enough and give you a list to go through to sort this issue.  Ive never owned a TT engine.  My Raptor 50 has the OS Hyper 50 in it and I havent touched the needles and it runs, idles, flies fine with the settings whomever built it did on the tune.

goodluck

chris6414

My Feedback: (10)

LS sounds lean turn it out 1/2 a turn. Set the HS to whatever the factory recommends. Start it up then spool up to about 30% to get her warm. If is sloppy rich with lots of smoke, then turn the LS in a 1/8 of a turn. Come back ti idle and see if it will idle. Pinch the fuel line and listen for the motor to speed up, then let go. It should idle for 3-5 seconds before it climbs. If it takes longer than that then tunr the LS in a little more. This will get you close. once the pinch test is OK. You should be able to idle for 30 seconds smoothly then transition to hover speed. A little rich is OK and better for the motor. If it revs right up and it cackles when you pull it back to idle then the LS is too Lean.

heli-john

I tried making it richer at the field but it seemed not to help. I messed around a fair bit but it got so no matter what I did it wouldn't run long enough to do a pinch test and after half a dozen cutting outs I gave it up.

TBH, I am tempted to bin it and get an OS.

BarracudaHockey

My Feedback: (11)

The best thing you can do to tune a TT 39 is to remove it and install an OS37

heli-john

I can go to an OS32!! Will that do!!

BarracudaHockey

My Feedback: (11)

37 is better, the 32 barely gets out of its own way

chris6414

My Feedback: (10)

32 is plenty powerful enough. I do loops and rolls with my Hawk Sport that is 12 years old. Better mileage too. I have tuned a .39 and was a bit more difficult than the .32 I have but doable. Setting the HS to stock then the LS to stock, it should run. Once running it need to rev up to clean it out to see where your at. Then you can set your LS to where it needs to be.

heli-john

I got rid of it; just gave up on it.

I bought a used OS32 and it started up relatively painlessly. I'd reset it to factory settings. It ran for about a minute and stopped but after a little tweaking it ran fine. Took it down the backyard to the grass to try it out and it cut out. Tweaked the jets some more and it ran fine, was about to lift off and it cut. Went to tweak the needles some more and found the carbie was loose. One of the screws had come right out and lost in the grass.[]

I am guessing it worked loose and each time I tweaked the needle it compensated for the air leak until the screw finally fell out.

Here's the good bit, I found the screw in the grass, whacked it back on and the engine ran a treat. When the awful wind and rain stops I can try it again.[8D]