HPI Trophy 4.6 Break In Issue

[thedude2470]

Hi all!

Picked up a Trophy 4.6 a little while ago, but am having an issue getting it running for break-in.
The engine won't even come close to turning with the air filter & housing on the carb. Took the air filter box off, and it started in a few pulls and idled perfectly. Put the air filter box back on the rubber elbow without the filter in it while it was running with no change. So obviously it's not getting enough air for the amount of fuel.

All needle settings are stock, the carb is 1mm open on idle, throttle is configured correctly, tried 2 different plugs and I am pre-heating the engine with a heat gun prior to each start attempt. O'Donnell 20% is the fuel as well.

Should i lean the high end up a bit? I don't want to run too lean for the break-in, especially since it's getting cold out. Maybe the plugs aren't getting hot enough for the rich setting? Try a different glow stick maybe?

Any help would be much appreciated.
Thanks!

 

[Zdragon71]

I've got the same engine on my trophy buggy now and to let it breathe better i stuck a 2stage filter on it in place of the inclosed housing that came with the 3.5 engine on the buggy. Even though i liked the idea of waterproof servos and resistant filter housing it is very restricting. With only a small hole in housing for air to enter. As a matter of fact its a traxxas intake and highflow filter I'm using now and it made a world of difference from the water proof one that came with the buggy.

 

[thedude2470]

Thanks for the fast response! Glad to know I'm not the only one having an issue with the stock filter setup. My first thoughts when I assembled it were "damn, that's not much room to breathe".
When I get a free evening, I will head to the hobby store and pick up something less restricting.
Thanks for the help =)

 

[thedude2470]

What do you think about modifying the stock setup? It appears that If I cut the plastic off of the part that slides over the filter (thus removing that small intake tube and making the entire filter exposed), it would still screw on from the top. Would look and function like an OFNA intake if you know what i'm talking about.

 

[Zdragon71]

I did think of modifying the stock one but just happened to have a spare traxxas highflow and intake pipe on hand. So i just used it instead. Plus i like the fact of having the outer filter also. Never have to pull the whole thing appart and clean it. Just the outer filter every time i finish running fir the day or every 4-5 tanks.

 

[thedude2470]

I modified the filter box, and it helped a lot. Car starts much easier now. 3 tanks into break-in and all is well. Thanks for your help!

 

[Zdragon71]

Good deal. Glad it worked out for you