Yeah, this is a common problem on the cheapest Go engines. Had the same deal with my .21 3 port. I replaced my carb with an Alpha carb and haven't had any issues. Three things to try.

You can get a new carb:
RB carb on clearance at Amain
New carb from X-Act (basically yours with better o-rings and parts)

Or you could just get new parts such as these o-rings or this HSN rebuild set. Just make sure your carb looks the same as the X-Act one. X-Act sells parts for the Go .21 3 port.

OR you can try cutting pieces of fuel line to use as o-rings. Sometimes that works.

Thanks buddy! I'll probably shoot for the X-Act Performance .21/.28 Complete Carburetor if I have no luck with the DIY gasketing.

Info?:

http://www.go-engine.com/pdt_view.asp?sn=268

DP.

We currently have a Team Driver running and testing the engine so far it looks good and has great power.

I ran the Champion engine produced by GO at the LiveRC track in the US. It had crazy power and torque. Held tune all day long. When drivers running the Nova P5 engines, and OS engines found what I had in the buggy they were amazed..

I ran my Champion a few days ago and could compare it back to back to a Novarossi Mito 7. Same day, same car model, same clutch. Both cars using the same setup, I felt no difference in power between the two and was able to squeeze a few more seconds of runtime in the champion using the 6.5mm restrictor (9:30 vs. 10 mins). My engine is 4 gallons old and the sleeve still goes up when you turn the flywheel with the cooling head removed. No play in bearings nor conrod. Highly underrated engine....

My Agama A215 during one stage of our nats championship, CERA 3 ports by GO Engines, amazing powerplant :

https://youtu.be/7ySgw5E8WdQ

Cera smooth n powerful, hard to get already

Will I benefit from changing my carb on a 5RHO to another brand (nova, OS, RB)? More reliability, ease of tune etc.
And what plugs are recommended for the engine?

I tried a nova carb in my engine just to see if there is any difference, both carbs held a consistent tune, in the end both GO´s original carburetor and nova turned out to be the same for me. If you are used to short needles you might find the nova a little easier to tune. The 2015 G5PT model is so easy to tune that it didn´t make sense for me to change anything.
Out of all the plugs I tried, the OS P3 is the best by far followed by the odonnell´s . The Novarossi plugs didn`t work out for me with the newest engine.

Go champion. 21. 5port
 

Hi I have this bout half gallon thru.

Motor runs hot 280 if lean anymore it gets hotter

Byron 25%

Os p3 plug

0801 pipe

Anybody know the stock needle settings?

Thanks in advance

Stock needle settings are not terribly important. I don't even bother learning the stock needle settings for my engines anymore; I just drip some extra oil into the cylinder, lean the carb until I can get it started the first time, enrich the carb until it can barely hold an idle, then start slowly leaning it again after the first couple tanks of fuel.

If it's running at 280F, either the mixture is too lean or the compression is too high. If you can't enrich the fuel mixture to cool off the engine without making it choke when first accelerating, then you need to add a 0.2mm shim to the cylinder head to lower the compression a bit. RC-Willpower sells shims for GO engines; the easiest way to find out which part to order is to email them from their website, and they'll tell you which part you need.

However, if you've been running it at 280F for a long time (more than a few runs), then the piston will already be broken-in to fit properly at 280F, and you'll have to replace the piston and sleeve to get it to run properly at a lower temperature.

Go engines in the past often ran fine at 280.. I had a Caster Grenade (slightly modded Go GX5R) which always ran at 290, whatever I did. It ran great and lasted long..

Depends on what the initial tolerances are, I suppose. Aluminum expands more than brass, so if the tolerances are loose, the engine will run better at a higher temperature -- assuming the carburetor is sufficiently insulated from the heat. The GO engines I've seen have plastic collars where the carb fits into the crankcase, but I'm not going to assume they're all made like that unless someone who knows more says they are.

I try to keep my engines at 230-240F. All of them, including my GO .18 and .15, seem to be happy in that range.

Also, it's been my experience that GO engines are under-shimmed from the factory. I own three of them now, and they all benefited from an extra 0.2mm shim under the cylinder head. It widened the range of usable fuel mixtures and kept the engines running cooler. Didn't seem to have any negative impact on the torque, but that could be because I always run 30% nitro to begin with; the weather where I live varies too much from day to day, I'd have to retune my engines every single run if I used fuel with less oxidizer mixed in.