Can't bring down idle on TRX 3.3

[Beer_Goggles_RC]

Just picked up a 3.3 Slash from marketplace. Trying to get the tune right. I've got crisp acceleration, but for the life of me I cannot get this thing to drop down to a decent idle without dying. The idle will come down with a very small idle gap (~0.3-0.4mm), but then the idle seems pretty sporadic. This is the 2nd trx engine I've had that I haven't been able to tune an idle on 30% the other was a 2.5 on a Traxxas rustler. On the rustler I rebuilt the carb and still had the same issue. It's like I can't richen the low side enough while maintaining a proper idle gap.

I'm certainly no nitro pro but I've ran OS b2104, Alpha dragon IV, and KE25SP2 with seemingly no problem.

Does anyone else have this much trouble with these engines? Or maybe tuning tips? I was really wanting to get a revo but if I can't figure them out might have to go with something else.

Planning to swing by the hobby shop tomorrow and pick up some Traxxas 20%. Running sidewinder 30% race blend currently.

 

[Beer_Goggles_RC]

So scouring some other threads I've seen a few people state that the trx engines tend to idle a bit higher than other engines. Maybe I'm just trying to drop it too low.

Also beginning to wonder if I'm being too particular of tuning this engine, considering this isn't an OS or Alpha maybe it just can't hold a tune as well? Although I gotta say, for about the same price as the TRX engines, the KE25SP seems much easier to tune.

 

[tudordewolf]

Just picked up a 3.3 Slash from marketplace. Trying to get the tune right. I've got crisp acceleration, but for the life of me I cannot get this thing to drop down to a decent idle without dying. The idle will come down with a very small idle gap (~0.3-0.4mm), but then the idle seems pretty sporadic. This is the 2nd trx engine I've had that I haven't been able to tune an idle on 30% the other was a 2.5 on a Traxxas rustler. On the rustler I rebuilt the carb and still had the same issue. It's like I can't richen the low side enough while maintaining a proper idle gap.

I'm certainly no nitro pro but I've ran OS b2104, Alpha dragon IV, and KE25SP2 with seemingly no problem.

Does anyone else have this much trouble with these engines? Or maybe tuning tips? I was really wanting to get a revo but if I can't figure them out might have to go with something else.

Planning to swing by the hobby shop tomorrow and pick up some Traxxas 20%. Running sidewinder 30% race blend currently.

It seems to be a pretty common issue with Traxxas engines that people can't get the idle down without stalling it, and that was my experience too. General consensus is that the carb is a bit under-designed, it'll work fine at WOT but it doesn't give a consistent mixture at low throttle, so it either floods the engine or starves it.

My solution was to put in an OS 11k carburetor and it absolutely sings, pricey solution though. I'm thinking of modding some sh.18 carbs with a "sleeve" over the carb barrel to make them fit the TRX engines, i bet they'd work great and are less than half as expensive.

 

[Beer_Goggles_RC]

It seems to be a pretty common issue with Traxxas engines that people can't get the idle down without stalling it, and that was my experience too. General consensus is that the carb is a bit under-designed, it'll work fine at WOT but it doesn't give a consistent mixture at low throttle, so it either floods the engine or starves it.

My solution was to put in an OS 11k carburetor and it absolutely sings, pricey solution though. I'm thinking of modding some sh.18 carbs with a "sleeve" over the carb barrel to make them fit the TRX engines, i bet they'd work great and are less than half as expensive.

Sounds beautiful In the video.

I've thought about getting the 11k. But for that price id probably end up just swapping out the whole engine for the dynamite .19

 

[tudordewolf]

Sounds beautiful In the video.

I've thought about getting the 11k. But for that price id probably end up just swapping out the whole engine for the dynamite .19

I hear good things about those. If you sell the 3.3 on eBay to fund it you can probably halve the cost of the swap.