ive had people tell me to get the o.s. .21 rg and ive had people tell me to get the thunder tiger pro.21 that the tiger is a faster better motor....if u could find it i probly would buy it..but i cant find anyone that sells it...ive been on acehobbys web site looking for dealers..everyone ive gone to donest have it on there web page.....u guys give me your input on your trial and errors...i seee the thunder come with a roto start....o btw i have a mbx comp..and the force .26 is weak my tmaxx runs way better

Quoted from Newman....

It's a good solid engine that sells for around $120. It's very much like the OS RZ without the tweaks. For what it's worth, this engine was designed by the same engineer that worked for OS for many years and then moved to Thunder Tiger a few years ago. This engine has nearly the same dimensions as the RZ does. The sleeve and piston are the exact same size and design and will actually interchange between the 2 brands. The only real difference is the 21R Pro has a square rod like the RG and the crank isn't relieved, it's the same as the RG crank. This engine doesn't make quite the power that the RZ does but it's really close. But it will smoke an RG on any given day and do it about 30-40 deg cooler. I run them in my Truggy and it rips. Rebuild parts for it are readily available. The p/s set is only $60 and a new rod is about $20. Hard to beat.

He doesn't have a website, (keep's cost's down). The number is 1-800-707-5464. He advertises in RCCA at times. Carries a lot of the most common stuff. Call and ask for the Thunder Tiger Pro .21B (non pull) or the Pro .21B-X (pullstart). '
The B is 119.95 and the B-X is 129.95.

What's the diameter of the carb on the Thunder Tiger? Is it 9mm or 7mm?

You can get the engine from Tower:

http://www2.towerhobbies.com/cgi-bin...?&I=LXFUU2&P=0

Sometimes you can find it new on ebay. I have bought two really cheap which were completely new.

It is also known as an Associated engine in US where it is used on the Associated MGT. If you get the one with roto and pullstart you should convert to a non p/s backplate since the r and p/s steals a lot of power.

is it worth payin 44 bucks extra for the os. 21 rg is like 109...ace hobby has the tiger pro.21 for like 130 something...and is it easy to tune and does it hold its tune...i have a ofna mbx comp and it act like it barley wants to take off and slowly builds speed i want to hit the gas a throw dirt and want it to fly..it aint even fast on pavement....lemme kno what u guys think

First I think that you should try to tune the Force engine or maybe get some help to do it. Some of these engines are a real pain to get tuned correctly.

Whether you get an OS RG or the TTR .21 engine, you need a starterbox.

I don't think that it is necessary to pay Tower's price for the TTR since you can get it on ebay for 100$ at the moment.

I have the OS RG in my LX Comp at the moment and it is a good engine and really easy to tune, but when it is worn out, I have a TTR engine ready to go into it.

i have no problems tuning nitro cars or trucks... i have a t-maxx a rs4 ss this ofna mbx comp buggy.. i also have to tunnel hulls one 3.5 one 7.5..i used to own a ek-4 with the .70 i sold it though....so i ve been down the road of tuning once or twice....its only on it 5 tank of fuel...but my t-maxx takens off alot quicker and runs top end better than my buggy..and im think it shouldnt be that way...right or wrong

YOUR buggy should smoke that T-maxx like a bad bannana......not only should that .26 be putting out more power than an .18 or whatever you have in it.....I got a P2 in my maxx, that's supposed to be a pretty fast higher end mill....my xb8 w/ an RG will just waste it any time on track or hard packed driving surface...in tall grass obviously not......but you need to tune that thing....what's it doing?? does it ever kick in or is it just real doggy on the bottom??? what gearing you set up with??

does the tt pro .21 have better bottom end then the os rg

the low end needle is flush with the brass ring and in prob 3 turn out...runs about 265 i stop the car hit the gas its like bup bup takes off but not fast..engine sounds like its reved up alil but but not all the way....its a new ofna with the electric start..clutch maybe slipping???....i dunnoimma take it apart and look at it..im runing monster horsepower fuel....ive tried everything when it seems like its wide open u hear it running out of fuel its like bip bip but its not going anywhere maybe 30mph...very easy to control which i would think i twould have power to make it hard to control

Follow the steps at the link below and that should make your buggy embarrass your t-max:

http://www.rcuniverse.com/forum/fb.asp?m=3455189

sounds rich on the LSN and lean on the HSN......

i did what that page said..still nothing...i kep richen it up from the 3 turns out and it got to 285..and cut off and wouldnt start again sounded like it wanted to...i also see air bubbles in m fuel line..what could be the cause of that..tank not sealing correctly???...when i hit the gas the engine is reved high but not moving...i was thinking the clutch is slipping..so i took the motor off and the clutch bell is real shiney..so it was slipping..im sure that will pick it up alil bit....i took the head and buttton off it had some scorein on the side of the cynd wall at the top...and im on my 4th tank....*** i havent let it get above 280...poorly designed engine....im thinking about getting the picco .27 and trying that..lemme kno your input

Replace all fuel lines and check the filter for leaks.
Air in fuel = hot and irratic running engine.

im looking at getting either the werks/picco.21 or the picco.27...i want my buggy to have lots of low and and scream on top

y not get a mayhem 26? its really fast and a great price
otherwise get the os rg i hear its a great motor!

leaning more towards the werks/picco .27....or the rb concepts .21 eco