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Give your Traxxas Revo a big boost of performance with the 21TM from O.S. It's the perfect drop-in upgrade, since it has a special manifold that adapts perfectly to existing pull-start or EZ-Start systems.
Features:
- Adapts easily to existing pull-start or EZ-Start systems, no mods required
- Manifold specially designed to fit directly into the Revo
- Clutch assembly bolts directly onto the crankshaft without modification
- Oversized crankcase cooling fins for dissipation
- 11K 3-needle slide valve carburetor
- High-performance LC3 glow plug
Specifications:
- Displacement: 0.208 cu in (3.41 cc)
- Bore: 0.669 in (17 mm)
- Stroke: 0.59 in (15 mm)
- Rpm Range: 3,000-35,000
- Output: 1.77 hp @ 29,000 rpm
- Weight: 8.57 oz (243 g)
- Includes: 11K carburetor and LC3 glow plug
From the Manufacturer
This is the O.S. Max 21TM Engine with the Revo Manifold. Direct fit for the 2.5 and 3.3 Traxxas Revo. Two year limited warranty.
Timothy s.
Reviewed in the United States on March 28, 2024
This motor is a night and day difference from the traxxas 3.3 not that the 3.3 is a slow or bad motor but this os motor is just the next level in every way. Low end has more punch as well as high end being much faster. When this thing hits second gear it makes my slayer look and sound like it wants to leave the planet. On the first day after breaking the motor in and after tuning it to where its running fine i blew the spring on my clutch shoes probably because the standard traxxas two shoe clutch system wasnt meant for this kind of power. Oh and I almost forgot the motor looks super cool as well which as we all know adds hp
Leo
Reviewed in the United States on March 19, 2021
Awesome upgrade perfect tunes and miner adjustments to get it were you want it
Customer
Reviewed in the United States on January 20, 2021
This engine is an absolute Beast! This engine is well designed. It is very solid. The headers is very solid and well designed. I'm very Please with this engine. Also very easy to tune, and it holds the tune very well. Excellent choice of engine OS .21TM
Jeremy M.
Reviewed in the United States on January 17, 2021
This OS 21TM is slightly larger than the TRX 3.3. Slightly. Don't get too excited, though.Yes, there's a little more displacement, and this better quality engine. It tunes rather easily. If I tune it conservatively, there's a little more pop on the low and mid end than a TRX 3.3 running running on the lean side. Keeps it fun without having to be lean and hot. That's basically what you're dropping almost $300 on. A little bit more pop with a little more reliability.I liken it to when buying a Toyota Tacoma. You can buy a 4-cylinder option, or you can buy a V6. The 4-cylinder option, the TRX 3.3, will get you by, but it will probably leave more to desire. The V6, the OS21TM in this case, kind of makes the experience just more pleasurable, yet without going overboard.Basically, just know that this engine won't make your Revo a RC Supercar. If you want your Revo to be a super fast car to crash into a mailbox and wrench on it every time you take it out, this product is not for you. If giant engines and crashing into mailboxes is your fancy, I'd suggest looking at big block kits, or starting from scratch with a racing buggy/truggy kit that has a lot of room for those giant .32 engines that are out there.Is it a better quality engine than the TRX 3.3?Yes. Doesn't mean the TRX 3.3 is trash, though.Is it going to be a night and day difference between your TRX 3.3 performance wise?No.Will it make a stock Revo 3.3 more fun?YesWill buying this engine make the chicks dig me?Probably not.
Customer
Reviewed in the United States on September 16, 2016
Love this engine! I'm not happy with the fact that the head screws came loose on the third tank of break in fuel. I lost 2 of the head screws the head lifted off of the cylinder I cant believe that's what you have to deal with when you spent twice as much to get a "quality" built engine.
Customer
Reviewed in the United States on March 4, 2016
Hands down an amazingly crafted item.Yes its an expensive piece " almost as much as a nitro car itself" but there is no comparing this engine to other enginesTurned my revo into a dream. VERY EASY to tune, major power, sounds SUPERIOR. If your reading this buy this engine for sure. It is night and day compared to the traxxas 3.3 engine. It also has 2 year warranty
jay newson
Reviewed in the United States on October 9, 2016
This is a powerful little engine. Make sure you tighten the carburetor before installation
Joseph E.
Reviewed in the United States on July 19, 2015
All I can say is this is an amazing engine. Just follow break in and you'll be having more fun then you can handle
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