MY UPDATE ON THIS I agree with the guy that said...why pay $400 for a gas .90 Tiger. Well it depends. If you have one already...its cheap and easy to do yourself. I got 2 of them. One I got give to me and the other was $2 at a yard sale. Swap meets have them cheap too. I can tap the head for a 10 MM spark plug and buy a $25 electronic ignition. Use 20-1 or25-1 0il and it should work , if not run to extreme conditions. But if you got to pay $400 for one ...I would forget it. As far as glow or gas...the spark will give you a more reliable idle, than glow. You know how a glow engine can quit at any time at slow RPM [X(] Capt.n

Captinjohn,
I'd love to geta detailed description of how to do the engine conversion, size of materials/ taps etc, and parts req'd, plus perhaps photos of each step along the way, as i'd love to take a crack at doing this.
Perhaps on another thread, and if you had the time to document it all.
Thanks!

I'd also like to see pictures of the converted engine and see the steps involved. Used ST90s are cheap; it may be worth a try.

Remember that the BME engine has a new crankshaft, piston and needle bearing rod, all designed specifically for gas. It's also got a gas carb and has had the case machined for the timer assembly. It may be comparing apples and oranges to compare a ST90 with an electronic ignition to an engine where all the moving parts and fuel system are different. Other than the case and head, there's not much ST left, and those remaining parts have been modified.

The proof, of course, is in the running and the longevity as well as the price you're willing to pay. I run my old Cyclone and O&R 60 on 3:1 gas and oil. I'd like to see how long a bushed rod would hold up at 20:1. Maybe with light loads and short runs it could last a long while, or maybe you run it at 10:1 and give up some power. I don't know.

Jim

On the conversion forum there is a guy running a ST51 on gas with igntion at 16:1 and having good luck with it. I agree that it might be worthwhile to convert this engine if it can be run without carbon build up. Would also like to see some performance tests. There is a ST90 laying in a drawer in my workbench that might be a candidate one day. It was also a freebie.

Jim

I don't know about anyone else, but I have yet to see an electronic ignition to use on a glow engine for $25.00, not even in 2008 when I first saw the conversion article for the ST-90 and also a TT Pro 1.20. Here in 2010 you can get a 20 CC gas engine that runs reliably and has some power for $230 and up. The weight of the ST .90 conversion is a lot lower, but there isn't any performance data on the website, a 13x6 & 14x6 are the recommended props (good except for the low pitch).

Only one user rated this in the User Review section and gave the engine a 1.5 and the following comment about uneven running and difficulty restarting the engine during the break-in was posted ( http://www.rcuniverse.com/product_gu...engine_id=1522 ) "The engine started and ran unevenly for around seven minutes at around half throttle, after letting it cool it proved awkward to restart. Once started the engine displayed similar characteristics and has done since. Obviously not wanting to void the warranty I attempted to contact BME for so advice. Having emailed BME on numerous occasions over a month, countless phone calls with no response and finally fax. BME have yet to respond in any way."
I did find one video on Youtube that was a Raptor 60 heli running this engine in a hover.

Where's the incentive to buy this at $400?

Researching an engine and making determinations from information on the internet? Preceptions?

First of all, nothing intended against albsurfer or his perception of the BME 90. And I do not own a BME 90 but have owned several Super Tiger G-90's and various gas engines. I do not anticipate buying a BME 90.

There has been some out of context data accumulated here. Mainly, the time line of research went across the demise of the original BME company ownership and the establishment of the new BME. This will explain the lack of response from BME during one of the events recalled. How were we to know?

One should not "Lock-in" on one experience report. Another person's experience with the BME 90 may be different?

Tom at BME answers every email that is received and every phone call during business hrs. If you dont get an answer leave a message and he will call you right back, he is probably talking to someone else. And for the fax? They dont have a fax number , so how can you send a fax?

I have a BME Super Tiger .90 running on Gas/Glow and it works perfectly....

AV8TOR

I owned a BME 90 purchased from Keith. Well made. Had a 1/4-32 Falkon ignition. They take a while to break-in but are reliable and well made. They will not make the power of a ST90 on glow fuel as originally claimed.

Back when they first hit the market, RCExl ignitions were, if I remember correctly $17.00 each if purchased in lots of twenty. There is a healthy markup on those bad daddys.

Hellow AVATOR, does you S Tiger .90 use needle bearings on the rod? How is the weather in your neck of the woods? We are in Florida now....warmer than good old Mich! Best Regards Capt,n

Yes, mine has needle bearings on the rod. Keith from BME converted it for me right before he stopped doing business. He was interested in trying the Gas/Glow thing on some of his engines and we exchanged some info on that, but then things went down hill for him. I hope he is doing well now, haven't heard. The new BME seems to be doing good...

Weather is great here. Our flying seasons are somewhat reversed from the east. In the summers it is too hot to fly except early in the morning (blah) or in the evening. It is perfect all day long right now except for when the occassional storm blows through.

Have fun and take care,
AV8TOR

The ST90 converted to gas that I have on my Tiger 60 is running at 16:1 like my 51 with no bearings on the rod. Haven't had any problems at all and yes the power is down some from glow but not as much as I thought it would be. I did machine the head some to raise the C/R and I am running a Walbro carb but otherwise the basic engine is as delivered. CH makes a Hall Effect mount that doesn't require any machining of the case and it's very easy to set the timing. It spins a 14X6 9800 to 9900. On a real good day it'll get 10,000. (my 95AX on 10% turns the exact same prop 10,300) Never tried either with a 13X6 so I can't be of help there. As far as starting goes it starts pretty easy after the first start of the day. I usually use the electric starter for the first start and then hand prop it after it's warmed up. Average flying will use about 6oz in 12mins. The little Rimfire plugs last 30+ hours and run around 16 bucks depending on where you get them. Mine is running a genuine CH CDI box and 1000 mah pack which is good for longer than I care to fly in a day. (An hours flying will require about 300ma to bring it back to full charge)

While I haven't owned the BME90 I have been considering buying one so I can run the same fuel as my 26 and 50cc stuff at 40:1. Also, I understand the needle bearings bring the HP up some more making it even more powerful and for a sport flyer any more than mine makes is just icing on the cake, IMHO.

Jan 2025
I have one for sale, NEW.
https://www.ebay.com/itm/22654743975...&segname=12000
Lower price here (no ebay fees)
https://www.rcgroups.com/forums/show...ntage-Rare-NEW

Just out of curiosity regarding mine, would you let us know when yours sells, and for how much.

Thanks,
Av8tor

A used engine recently sold on another forum, was Listed for $225.