f2racer

Well my Pro-36 got three 6oz tanks in it and I decided to give it a go in the air even though it wasn't broken in. I installed it in my 3.75 Uproar (didn't weigh it, but I think it's between 1 and 1.5 oz less than the GP-42 it replaces, and it moves the CG back a tad). Idle wasn't consistent, and transition absolutely sucked, but I was amazed at the power on the ground running rich so I thought I'd give it a go. Running a 10x5 prop, it took to the air with some throttle coaxing through transition. I was immediately aware of the speed difference at full throttle. Maybe it's the 10x5 prop (I'm used to an 11x3 prop with a GP-42), but the Uproar was quicker than a TT Pro-46 (11x4 prop) equipped Somethin' Extra that was also at the field. I made a low pass at about 1/4 throttle, gave it full throttle, and immediately pulled it vertical. The plane accelerated vertical like a bat outta hell and quickly became a dot in the sky. I've never had a plane with this kinda unlimited vertical capability! Even rich, it's spinning the 10x5 prop in excess of 13k rpm. I'm going to pick up a 10x4 and 9x5 to get the engine really revvin'.

Now the bad part. I'm no expert at engine tuning, but this has got to be the worst running motor outta the box I've ever had. TT mustta been on crack when they recommended 2.5 turns out for the initial run. Mine was at 4 and I still had to back it out some. Transition from anything below 1/2 throttle to full was very labored (had to play with the throttle quite a bit to keep it running), it wants to bog badly! And when I throttle down, it seems to sit in high idle for several (5-10) seconds before dropping rpms. I'm thinking that they set the idle needle valve way rich at the factory. What do you guys think?

So far I'm super impressed with this motor. It's EXTREMELY tight. So tight in fact that I thought I was going to have problems with the electric starter! I'm hopin' that I can cure the transition and idle issues by next weekend, since I intend to keep it in my favorite plane right now...

HELP!

1Jimbo

My Feedback: (2)

I had the same problem, come to find out TT knows about it. They will give you a free low speed needle valve screw that WORKS if you contact them. These little engines are incredibly strong. I have two that I use in combat. I think it is the only engine TT makes that has a chrome liner,so if you know how to do timing work you don't have to worry about the liner peeling. If you look inside you will also see that the windows in the sleeve are a perfect match to the case. Also the piston and liner FIT very well. They did their home work on that engine, but not on the low speed needle.

1Jimbo

My Feedback: (2)

I run a 9.25x5 APC pylon prop on my TT.36's but I have a Ultra Thrust muffler on them. I'm turning about 18,000 rpms. I do think that will help you much but that's what I do for combat. :stupid:

f2racer

1Jimbo,

Are you sure about this? I spoke to tech support over at Ace and they said that a while back they had a bunch of high speed needle valves from the old factory that they'd send out to people who had problems with their Pro-36s. Supposedly only difference between the old ones and the new were the size of the O rings (larger on the older model). They no longer have any more, but suggested that I try putting some fuel tubing over the needle valve and where it connects to the carb. They also said that they had a bunch of Pro-36s that came over that were too tight, and if that didn't work to send the motor to them so that they could put a new cylinder piston combo in. Are you sure about the low speed (idle) needle valve? If so what was different with the ones that you got?

Thanks!

uciflylow

I have a TT.36 on a LT-25 trainer that will hover with this engine running an APC 10x5. I fly it like a fun fly plane and have a ball with it and the engine runs great.
It sounds like it may be a little rich on the low side. Pinch the fuel line at idol and if the engine speeds up turn it in a little at a time untill it doesn't speed up but a little before dying on the ground. Like I say Mine Runss great!!!

Mighty Mouse-RCU

My Feedback: (145)

I aggree with uciflylow, Me thinks it rich on the low end. Maybe a bunch rich.

dmajchrzak

My Feedback: (17)

I JUST ran in two brand new TT36 PROs on my Twinstar.
The transition stunk, until an experience member of my club leaned the idle (low end) mixture screw... Now, there is NO bogging down during acceleration....
I too think TT is loony recommending 2.5 turns out on the high end. I start at 4 turns.

Once adjusted ( which is easy ). This engine cranks out the HP. I love it.

I recommend leaning out the low end. I think you'll love your TT 36 Pro... I love mine.

f2racer

Do all of you guys have the low speed needle valve that came with the engine? Me thinks that the low speed idle may be WAY rich as well. I'll try adjusting it down to fully closed and start the tuning process from there. I never had to turn any of the low speed needle valves more than 1/2 turn before my Pro-46s started to hum perfectly (I've got three 46s and one ran so well that I took to the air after only 1 tank. It's yet to deadstick on me!), so that's all I tried adjusting on the Pro-36 during break in. BTW, is very fast fuel consumption an effect of running rich down low? I literally drain my 6oz tank after only about 7 minutes of run time (I can tell because it starts to get bubbles in the fuel line on the ground and filling the tank shows the tank is virtually empty)... I can usually get in excess of 15 minutes outta 6oz with the GP-42 that I had mounted on my Uproar, and still have more than 1/4 tank when I land.

uciflylow

I know mine has the stock low end needle in place and it runs as well as any TT Pro or OS FX that I have.

Many flyers have a hard time adjusting the low end. See if some one will help you with it. I bet it will be a new engine. You may want to try some different glow plugs also. My MDS .58 perfers a idol bar plug and almost everything else I have runs fine with a regular plug.

I'm running a K&B 1L in the .36 and almost all the other engines I have.

m.gramling

My Feedback: (8)

For what its worth. I have a TT 46 I bought in the spring.

The low in was way to rich. I started leaning out about 1/8 turn at a time. It took a while but I finally got it set. It your 36 has transition like my 46 you will definely be pleased.


Just takes a little patience getting a new motor broken in and set. Trust me I know I started flying w/ a MD 48. then moved to a ST 45. So i learned a lot about paience w/ setting up new motors.

f2racer

Fixed, but the solution was 2 step. First I had to turn in the low speed/idle needle valve over 2 and 1/2 turns from where it was. The freakin' thing was over 6 turns out from the factory! Second, while fiddling with the engine, I noticed that the high speed needle valve was loose. I slipped a 6mm silicon vacuum tube over the needle assembly to keep it form suckin' air in through the needle valve. The results were amazing! The engine performed 1000% better. BTW, this engine is a monster. It hangs my 3.75lb Uproar significantly better than my TT GP-42. Turnin' an APC 11x3 prop, may try a 10x4 to see if I can get a bit more vertical out of it. I'm also thinkin' about putting on a 9x6 or 9x7 to see how fast the Uproar will fly

rkrig

My Feedback: (2)

f2racer

Glad to hear your 36 has found its humm. I have a 46 that was set way rich on the low end and likes about 3 1/2 turns out on the high speed. Sounds like just about everyone has had the same experience. Have fun with it.