same here, using the stock carb can get frustrating sometimes to tune. Now I'm using a nova carb and now, its tune once and forget about it. Runs perfect every outing. Really an awesome engine. Getting my third one soon.

I had a radical 621T about 5 years back and loved it. It was so worn out after 2 years of racing I retired it to the trophey shelf but always smile when I look up at it. I was looking to get another but its been hard to find anyone who sells them around here ( east coast US). Does anyone know where online that has good deals on these bad boys?

Dave @ GotNitroOnline.com

I think the carbs are great and have actually used them on other engines, they do tune a bit different and have a aluminum carb body so they arent supposed to get too hot, or they can vapor lock, the radicals run between 190 and 230. And what other carb do you know of that has all the needles on the same side ? Makes it way easier once you get the hang of it !

Well im glad you like them. My werks carb is aluminum and I never had a problem with it. I just think that ops should come up with a better carb. I had no problems tuning it. The carb would start to chang tune, it would go lean then rich with temps at 220-230. Its also huge, I spent 2 hours modifying my xb808 throttle to get the correct spring tension and still have enough throw for my brakes. I still will keep running these motors now that I found a carb.

I rebuilt my old OPS 621t and i am having some trouble with the carb. Never had any problems before but now i am. So, i am gunna put a different carb on it. What carbs are a direct fit? I have an orion carb, but i noticed the neck is a lil long.

edit: disregard, got my orion carb to fit. will test later.

I have a werks 2010 carb on my 621t and an older grp carb on my 628, by the way the tecno motors are the same as grp. Anyway I noticed the only difference will be the carb neck orings. Test fit the carb without the orings on it and see how much distance you have. If you can use the factory carb orings use them if not put the radical orings on. And most important seal it up. The radical carb necks have 2 orings at least the all alliminum ones there are some composite carb necks out there that have only 1 but I deffinetly do not recomend running those as I have heard of those falling off the motor. I seal my carb neck with red rtv high temp sealant and also seal up the locking collars with red rtv and make sure you seal up the threaded side off the locking collar screw to. After that dries I put a bead of Lucky 7 engine sealant around the carb neck and both sides of the locking collar. Its crucial to make sure you seal up around the locking collar if you do not have an o ring on the bottom of your carb neck. I know this is alot to do but if you do it right you wont have to mess with it for the life of the motor. My 621t has almost 7 gallons on it with no problems and I am kicking the crap out of brushless buggies at my home track.

whats the difference between the 621t and 621p thanks

Sorry but these motors will not run in a associated they need to be in some thing of quality like a mugen

The 621t is suppose to have more torque which makes it perfect for a truggy. It also has the new Cinderella head. My buddy bought one and put it in his MBX6 buggy with a 14t bell and still had plenty of power to clear any jump. We mated it to the Radical pipe with one big and one small spacer, a P4 glow plug and was getting 10:30 minutes a tank.

do people still run these engines...?

they have a "exclusive" re seller in perth,Australia... and looks like they still have the gold cinderella engine instock..

doesnt look like mantua model are doing much in dedicating time iron out the rough edges.. and putting any bling bling other than a nice chrome look to them...

https://www.mantuamodel.co.uk/prod.a...131&imgstate=0

[QUOTE=MasterComander;10135519]do people still run these engines...?

they have a "exclusive" re seller in perth,Australia... and looks like they still have the gold cinderella engine instock..

doesnt look like mantua model are doing much in dedicating time iron out the rough edges.. and putting any bling bling other than a nice chrome look to them...



Yes there are! I 've been dealing with rc cars for more than 20 years. These are the best engines BY FAR.... As for the looks.. wel,l i belive that they are the most beutiful engine i have seen, but this is a subjective opinion, the objective opinion is that you have no alternative if you want top power on the truck, OPS/RADICAL is the way to go. I have ordered one now from GOTNITROONLINE. Great guy to deal will, feels like i know him for years.. Will post feedback..........of the shocking faces of my co-races when they see this engine on the truck!

What is a good turbo plug to run in these?? would the medium Werks one work with it?!?!

Dave has hot plugs that work. GotNitroOline.com #7's. I have ran Odonnell 99's.

Well, After 4 gallons the engine starts to show its full potential.. The low end is more than you can imagine. I use half throttle in order to clear jumps right after a tight turn. The motor starts in seconds and idles forever! The carb settings are richer than suggested and still the power is more than enough. I ve seen engines in my local truck that give up at 4 gallons and my 621T had no flame out from day one. As soon as you find card settings the engine does not flame...ever!..Works like an e motor..haha its like switching ON - OFF!