grant-RCU

My Feedback: (10)

I burned the piston on my TT pro 46. Replacement piston and sleeve is $40.00. SO i really dont want to put the money in it. It also needs a new bearing.

I have been running it with a macs tuned pipe and a 9x8 apc prop. This thing really did scream at 120 mph top speed. On my last WOT flyby she died on me. The engine flet rough inside so i pulled it apart to find some burned pits on the piston and a chunk missing.[:@] I was running it plenty rich and it had a nice smoke trail at all times on 10% omega.

Which engine do you reccommend for a replacement? I though about the GMS 47 because the price is not bad and the replacement parts are cheaper. Keep in mind i will be running the new engine with the pipe and small pipe.

Razor-RCU

My Feedback: (50)

EDITED HERE:: Do yourself a favor and do not continue reading down this thread, it gets UGLY! ::

The GMS has the price point, although it seems to be a gamble as far as quality goes--- The Magnum-52XLS was on sale for $79.99 also

Harry Lagman

Based on my experience with both the TT .46 Pro and the GMS .47, I would rate the TT superior in almost every way. I strongly recommend getting another TT and using your old one for parts.

tinman 4009

how much for your tt 46 parts? i have one with good piston and sleeve just broke the carb and bent the crank on mine . the pavement runway wasnt forgiving just like you it wasnt worth spending the money for new parts . guess ill have to save up for a new motor

delman

When part of my aft bearing failed on my 50sx it put several nicks in the top of the piston and broke a piece off as well. It probably was not too lean - just the retainer for the balls failed on the aft bearing on your engine. The TT46 PRO is one of the better engines.

ChuckN

The TT .46 is a good engine for the money. So is the Supertigre GS45. And it has true chrome plating on the cylinder bore. I've modified a few of them and they perform very well. You can open up the exhaust port without causing the plating to peel. You can't do that with a nickel plated engine like TT and OS. If you really want to go fast get a Jett 46. They seem expensive up front, but you need to remember they come with a tuned exhaust system and will outlast any asian sport engine available.

elmshoot

My Feedback: (6)

I would buy another TT .46 and get the tower Hobbies muffler it is good for about 7-800 RPM and only cost $15!!!
Sparky

Mediaman

My Feedback: (1)

Consider the Magnum 52, or a MVVS 40 or 49.

Carlos

DarZeelon

Grant,


This is a really good deal on that set.
The last time I looked (several threads about it here), it was $68; nearly 90% of the price of a new engine.

BTW, why don't you exercise the warranty?
Did you mis-use it somehow?
Are speed runs prohibited by the warranty?

Gene Chernosky

My Feedback: (182)

As Dar says, do you have a warranty to work with? ...TT's have a 3 year warranty. It definitely sounds like a rear bearing failure of some sort...something that should easily be covered in the warranty.

FWIW, most 'sport' engines don't have bearings that are made to 'go' at higher RPM's for the most part of the running time on the engine. If you plan on using it that way you might want to consider high speed bearings or ceramics. Forget Boca Bearings...WAY to high!...try RC-Bearings.com.

Rocketman612

My Feedback: (85)

I agree with Gene. Get another TT and upgrade the bearings. Then fly the snot out if it

Pete

grant-RCU

My Feedback: (10)

Thanks for the replys guys. I think i might try the magnum 52 since its on sale for the same price as the TT 46. I figure it will give me a little more speed. I have also heard good things about global's service. I didnt send in the warranty on my tt so i am stuck with it! I do believe the front bearing is almost gone as there is some play in it and the rod has been grinding into the bottom of the crankcase.

DarZeelon

Grant,


Before you buy the Magnum .52XLS, send a PM to Ernie Misner (in this forum).
He encountered bad bearings in that engine too.

If you put a set of quality bearings in that engine, you wouldn't believe the speed you may see.


Go to Paul at [link=http://rc-bearings.com]RC-Bearings[/link] for a good offer (ceramics are $24, less than Boca's Hi-Speed steel).
Getting a set of WIB bearings will be best in steel.

Rudeboy

They must really be using low quality bearings in these Chinese engines...

I have run SKF steel caged 608 bearings up to 100,000 rpm on several occasions (turbine), and I yet have to have a bearing cage fail on me! I do admit that I'm walking the line here, putting caged bearings in that thing... but so far so good.

Gene Chernosky

My Feedback: (182)

If you have a receipt less than three years old from an authorized TT dealer you are still covered with a warranty...tear'em up!

If not...well...yes...you are stuck with it.

IMO, the Magnum .52 won't handle the higher RPM's any better...the same thing will probably happen at some point in time. The 'sport' engines simply don't come with bearings of the quality needed to run the 'H' out of them. MVVS, Webra, Rossi, Jett, Nelson, etc., yea, run the snot out of them...they LOVE high RPM's!

DarZeelon

Winibald,


...I call these bearings "caster bearings"...
No, not Castor as in Castor oil, still among the best oils around, but caster as in self-steering, shopping cart wheel.

RPM limit - 2,000... OK... 5,000.

XJet

Actually I've found that TT's bearings are vastly superior to those on the multitude of Chinese engines that are flooding the market.

I've got a GMS32 that I'm simply afraid to start up with its original bearings because they quite honestly feel like they've got rocks in them.

All the Chinese bearings I've seen are decidedly low quality and the first thing I'd do with any motor from that part of the world which I intended to prop for more than modest RPMs is replace those bearings with decent ones -- *before* I ran it.

ChuckN

Yeah, those asian engines are a real good deal

rambler53

My Feedback: (494)

I read this TT .46 engine sounds like junk, but posts here show in spite of that flaw and short life run, suddenly GMS .47's would be inferior to the TT? Based upon what? The gold colored head bothers you? Sweeping remarks all Chinese engines being basically crap is not my experience. From my experience nothing can be further from the truth. The GMS engines run great for years. www.mecoa.com gives a $20 trade in on dead TT engines for GMS and Mecoa engines. I've owned 3 or 4 GMS engines and presently fly about 3 Mecoa engines, that are all ABC and haven't slowed down at all from their 14,800 rpm. They run great, just like the Magnums and ASP engines I also own, ringed and otherwise. Tower Hobbies .46 also is a great choice for low dollar engines that perform very well. For some reason people who never owned any of these engines have something bad to say about them. Like Chevy trucks and Ford trucks, usually people haven't owned both within the same decade and have biased remarks for one brand over the other without direct experience with them, and you'll find both of those truck owners saying something bad about a Dodge truck they've never even sat in once. Frankly, my OS FX .46 is very overrated because it's $100 and my $50 engines run as good, as fast, and as long, I wished I bought 2 more Tower engines instead. I like my cheap engines as much if not better. For one, I dislike the crude tuning of rear needle valve engines like on the LA and FX. The GMS and MECOA come with a finer tuning carb with the needle up front where it belongs. Many seasoned pilots at my field are pulling 4D and 4BK carbs off their V, FSR, and SF engines and running them on their FX engines. Wonder why? One click on my FX, and I'm running horribly. Front needle valve carb engines don't have such a huge change in one click of the needle adjustment. MY Chinese engines run cooler too. In fact, my Super Tigre .45 ABC China made has the finest tuning increment I've ever experienced in 30 years of any engine, just like the Italian ones I stil have. I like that feature. My .46 FX has three seasons on it, this is Florida, seasons are 40 weeks long as 12 weeks it's too hot to fly or I'm recovering from a hurricane season. But many hours are on all these original engines. The 4 stroke break in didn't kill them like extreme commentaries suggested in another post by these same biased writers here too. GMS is inferior comment is from a pilot who probably never flew one. I think the shorter list is what doesn't run good.

Like these TT engines that break all the time at my flying field, on this RCU page, and other owners who must replace bearings with aftermarket ones for another $26. What a waste of time to brag about a TT engine.

$49 for a Mecoa sounds better, so trade in your TT and never look back. RJL made some milestone engines in their time, and they are putting out excellent consistent quality today with a $20 trade in allowance for those crappy TT engines that are prone to break. I was never crazy about nickel OS engines for $100 when $50 does the job with a chrome piston. The peeling process I hear about so much must indicate to me a design and manufacturing defect that continued through many years. Chrome is stronger, and most Chinese engines are chrome. I don't see many American engines around, $200 for a FOX? No thanks. If you're afraid to run a GMS engine you never started because you think your bearings are junk, that's a shame. I always went ahead confidently with my warranteed engined and never had a problem, 100's of flights on them, and they hardly show their age except the gold and purple heads are faded. Big deal.

Spicoli

Krosypal,
I have 2 GMS 47's and I have had the opposite experience you have had.I would take a TT or an OS over a GMS any day.Out of the 20 engines I own the only brand I would not buy again is GMS.

rambler53

My Feedback: (494)

If you have a GMS engine, please sell it to me for what you think it's worth. One man's junk is another man's treasure.

daven

My Feedback: (1)

If you really want to go fast, check my nelson in the Marketplace

Harry Lagman

Hey Krosypal, glad to hear you're lovin' your GMSs!

I don't own a GMS, TT or an OS FX/AX but I've worked with and set up several examples of each for other guys (mainly students on buddybox). The first couple of GMSs really impressed me - one guy's .40 pulled 14,700 with an MA 10x6 and was totally dependable. As I sampled more engines, I saw some inconsistency, especially with the .47s.

If you're putting a newbie up, there's a lot of responsibility on you the instructor to set the guy's engine up so it doesn't sag on take-off or otherwise misbehave. Part of our circuit is over the sea, so reliable engine performance is critical. What I don't like about the GMSs is their inconsistent fuel pick-up capability. Some are really good but others are a little variable. Some can be set up with a good needle and then mysteriously lean out and dead-stick on flight number four after three perfect flights. Another thing they're prone to is stripping the muffler bolt threads. The three or four each of the TT and OSs I've set up have held their tune and perform consistently.

I can't vouch for GMS long term durability - so far they're lasting as well as anything else out there but there are not yet any real high mileage examples.

XJet

I'm with Harry on this one.

*Two* of the three GMS engines at our club have had the muffler bolts strip out (and no, they weren't over-torqued -- they're badly designed).

Mind you, having to use an alternative muffler is the best thing that has happened to these engines. One is now running a TT46Pro muffler and the other a Tower muffler. Both are running a *lot* better than they ever did with the GMS muffler but they're still not perfect and deadsticks are not uncommon.

Before anyone suggests that it's tuning -- the same guys have TT engines that they've tuned up and they run like clockwork -- never dying and always providing reliable good power.

Today there were two TT-powered planes at the strip, one with a TT42GP and one with a TT46Pro. Both started straight up and didn't even need their needles tweaked -- despite the fact that neither had been run for nearly 6-months.

By comparision, one of the same guys has a GMS47 in his other plane and he deadsticked twice -- until he fitted a Tower muffler to it.

And as for those Chinese bearings -- well you're welcome to come feel the "bag of rocks" that pass for bearings on my *brand new* GMS32. It's not pretty I tell you.

But my TT46Pro has been running for at least three hours a week, for a year (getting some pretty hard work) and it is still as smooth as silk and the bearings are perfect.

The GMS *is* more powerful than the TT46Pro -- but all that power's just useless when the flame goes out on take-off.

Our club members are still buying TTs but have sworn off GMS. Why do you think that might be? :-)

rambler53

My Feedback: (494)

Ok, GMS appears to have some problems, does that make them all bad? Stripped threads a bad design? Please! How many ruin OS heads with a glow plug wrench? How many peel the nickel off OS engines from bad break in procedures? How many snap mounting ears off engines not removing them properly? The same hobbyists strip the threads out of grade 3 bolts too maybe. blaa blaa blaa.


Edited like the rest of you! Thanks, this is fun. Edit edit edit. How about taking responsibility for what we say first, ok? What comment? Edits are so much fun. You removed your remarks, so my former comments are invalid, how interesting. I like that picture of the crashed plane, says a lot.