Replacing my TRX3.3

[Monteman]

What is the motor of choice in a Slayer to replace the TRX3.3?
Buddy mentioned the OS.21TM Revo. Seems a bit pricey to me at $300 at the LHS. What else is there that can hold a tune in the wind. My TRX3.3 is unable to hold a tune and i figure if i have to replace I'm gonna put something else in there and use the TRX replacement to get a new one for a spare. Relatively new to nitro, got into it for the first time last summer. Also i do not do much racing if any, I'm just a backyard basher.

 

[2revo1maxx]

Well you could check ebay for an os 18tm. About the same power as a 3.3, but very tunable and a much better powerband. Most people are asking about 150....if there's one available.

 

[Metalhead Matt]

I'd seal that engine and try again before giving up on it. 3.3's scream when they run right. Seal it, change the fuel lines and glow plug and make sure the tank lid is sealing.

 

[Monteman]

I have done everything i can think of to try and fix the wandering tune issue, ran out of ideas. Buddy of mine bought a revo 2008 plat at the same time and he literally never has to touch the screws once he gets his tuned... mine is constantly being adjusted. no lack of power out of it but the temps are impossible to keep stable up and down so fast. i replaced the carb assembly, changed out the lines, bought a new tank, replaced the seals on the new tank, checked the seals behind the flywheel, glow plugs are always new, my temps would spike so hard and fast the plugs would just foul and burn up, i honestly think i went through about $100 worth of plugs (mccoys, traxxas, and one other brand the LHS had forget the name) last summer over the span of 2 months just bashing and trying to tune. Definitely willing to buy a new motor given a good enough review. also willing to power it up a bit as well as i am converting my slayer to a revo this spring as well.

 

[ThunderTiger]

Did you seal around the carb and the engine backplate and have you checked the head bolts are tight ? Even the smallest air leak can wreak havoc on tuning.

 

[Monteman]

yes i even had it in to the LHS to take a look at for me and they said there was nothing "out of the ordinary" about it. They were at a loss to explain it.

 

[Metalhead Matt]

So you sealed the carb throat, backplate and header? Maybe take a look at the hsn seat. It's possible for them to come loose or for the plastic to break if it's tightened too much. Are either of the bearings leaking?

 

[2revo1maxx]

I have done everything i can think of to try and fix the wandering tune issue, ran out of ideas. Buddy of mine bought a revo 2008 plat at the same time and he literally never has to touch the screws once he gets his tuned... mine is constantly being adjusted. no lack of power out of it but the temps are impossible to keep stable up and down so fast. i replaced the carb assembly, changed out the lines, bought a new tank, replaced the seals on the new tank, checked the seals behind the flywheel, glow plugs are always new, my temps would spike so hard and fast the plugs would just foul and burn up, i honestly think i went through about $100 worth of plugs (mccoys, traxxas, and one other brand the LHS had forget the name) last summer over the span of 2 months just bashing and trying to tune. Definitely willing to buy a new motor given a good enough review. also willing to power it up a bit as well as i am converting my slayer to a revo this spring as well.

Don't forget that how you run it will affect the temps too. If your engine is working hard in grass it will run much hotter than if you were on pavement. That's without changing the settings at all. I would try doing something consistant...back and forth, the same thing for a whole tank and then see how it acts.

 

[Monteman]

all tuning was done on pavement. i bash with a couple of hardcore Rc guys, so the help and tips i had while trying to diagnose this was endless. i have honestly given into the fact that the 3.3 will be replaced and that was the original intent of this thread
Throw some ideas at me, i already know of the Os .21TM(REVO) and the Picco Red Dot .26 is there anything else i should look into?

 

[Metalhead Matt]

O.S. .18's run real well from what I hear. About the same power as the 3.3 but way easier to tune. More low-end too. A .18 would be easier on the drivetrain than a .21 or .26. All depends on how much you want to spend really.

 

[Monteman]

money is about half of what they would cost, gotta love the LHS employee discounts.

I have heard the OS engines hold a tune really nice. so the .18 is a more than enough motor for the revo? I'm not looking to be racing it or anything, just bashing around.

 

[2revo1maxx]

It's a great engine, like I said earlier. The 18tm is discontinued, but there are still some new ones available. The 18 tz is a good one but not a direct drop in.

 

[hamz9561]

You might also look for a Picco .26 Maxx. It's a really solid Big Block for the Revo.

 

[Monteman]

It's a great engine, like I said earlier. The 18tm is discontinued, but there are still some new ones available. The 18 tz is a good one but not a direct drop in.

whats the "not direct" part on the Tz?

 

[2revo1maxx]

whats the "not direct" part on the Tz?

The clutch.....I think all you would need is an adaptor of some sort.