OS 37 SZ-H vs TT 36/39

[Suzuki_kid_1984]

Hi all,

I purchased a TT raptor 30 a few months back which came with the stock TT36H engine. (I think we all know where this is heading)

Being a heli beginner I've already had my share of teething problems with the engine, mainly surrounding getting the darn thing started and settings dialed in accurately.. This isn't helped by the fact that the instructions are somewhat elusive.. at best. No matter what settings I try none seem to really work, which makes me wonder if my field time will always be spent chasing the needles, rather than learning to get the heli off the grass!

After reading countless forum articles it would seem the choice of engine isn't exactly helping matters.

The more I read about the OS 37 SZ-H the more it's making sense to pull the TT36 out and start over with the OS. I'm really liking the fact the needles are on the same side for ''convenient'' tuning, and the low speed needle is actually visible and not hidden in the barrel!! the instruction manual is brilliant too..

Would welcome your thoughts on the engine, and more importantly opinions regarding choice of muffler/silencer? I've read good things about the Hatori range?

Tried to find a similar topic in this section, but after 20 pages nothing really covered it.



thanks in advance,

Byron

[Si_B]

I've got an OS37 in my Guai NX4. Think I only tweaked the main needle twice and it's running perfect. The TT engine is tricky to tune as the bottom needle adjustment effects 50-70% of the range. The main needle only really adjusts the very top end, which is not how most motors work. They also run very hot.

Only thing worth looking at is cost of the OS37 against a good second hand Raptor 50 with a decent motor in I already. Hatori are good mufflers, but expensive and maybe overkill on an 37 unless you are looking to reduce noise or increase power.

Hope that helps, but you can't go far wrong with an OS in general.

[Suzuki_kid_1984]

Thanks for the input. It did cross my mind already whether it was worth getting the 37, or just go straight to a 50 size and only spend out once on something which could serve me a lot longer. Guess the 30 just appealed due to it's good beginner friendly traits and relative cheap parts bill

Regarding the muffler I'm certainly open to ideas as being a beginner I appreciate I'm not going to benefit from the power gains whilst learning to hover etc.



Regards,

Byron

[pgkevet]

And for more economical options:
Just Engines Online Ltd A.S.P.

[KevDavies]

Thanks for the input. It did cross my mind already whether it was worth getting the 37, or just go straight to a 50 size and only spend out once on something which could serve me a lot longer. Guess the 30 just appealed due to it's good beginner friendly traits and relative cheap parts bill

Regarding the muffler I'm certainly open to ideas as being a beginner I appreciate I'm not going to benefit from the power gains whilst learning to hover etc.



Regards,

Byron

if you want to go to a 50 just get the bits to convert your 30. it'll only cost about 20-30 quid if your savvy to convert to a 50. Then throw in an OS 50 hyper and forget about it!

Just out of interest what is the standard TT engine doing?? Ive never had a problem with these and they are easy to tune generally

[Suzuki_kid_1984]

Funnily enough I have just been looking at conversion kits online. Like you mentioned seems a shame to waste the heli I have.. Well I fired the engine up fine last weekend (when it was actually a tad colder than today) and it was idling quite well. Didn't get to tune the whole range as I didn't want to annoy the neighbours too much

Took the heli out to my local park today, settings un-adjusted from above, but it didn't fire at all. It almost seemed like the engine wasn't putting up much resistance to the starter? I did check the tightness of the glow plug when I noticed this, just to check air/fuel wasn't leaking. I did wonder if I'd floaded the engine so ran through that process etc.

The engine wasn't even giving the popping sound, like it wanted to fire.. very strange.

Checked out raptor technique and the glow / flooding issue seemed the likely cause for the engine not firing.



Regards,

Byron

[KevDavies]

Thats not flooded thats no fuel in the engine. Did you prime the engine before trying to start??

Without attaching the glow driver, open the throttle fully and put your finger on the end of the exhaust blocking it, and give the starter a quick burst to prime the engine. Then put throttle back to bottom attach glow driver and itll fire then.

and when you tune the engine turn the bottom in just a touch from factory settings to get it to idle and leave the top needle until youve a gallon or so through it. Its a pity your miles from me or id come n tune it for ya

[Suzuki_kid_1984]

Yep primed it, however you have mentioned something I'm not doing, that's opening the trottle fully before pinching and giving a quick starter burst..

Keen to give that a try tomorrow before I make any decisions on replacing the engine!

Really appreciate the feed back on the settings and the offer to tune. Just a bit out of the way here, and no local heli clubs within easy reach unfortunately.

I'm also keen to get a few more glow plugs as I'm not convinced the ones I have are OS nr 8 etc. No markings whatsoever on them...




Regards,

Byron

[KevDavies]

if its genuine OS they are marked.

No need to bin a new motor mate, all are fixable. If you need any help PM me and ive done a comprehensive rebuild thread on here if you wanna have a look too

[Suzuki_kid_1984]

Brilliant thanks for the help.. Starting to think I should have posted in the beginner section before contemplating a new engine haha..

Will give it another try tomorrow and hopefully be able to post some good news!



Regards,

Byron