trx 3.3 breakin trouble.

[Traxxas revo20]

Hi, i just rebuilt a trx 3.3 with a new piston and sleeve. I went to try and break it in and it is making a weird buzzing noise and if you even gently touch the throttle or any tuning screws it revs real quick and wont come back form rev.

[f687s]

the sleve is probally tight for now

[Traxxas revo20]

so, i just need to get it running and leave it? Is it typical for it to idle real low and almost die? Like i said if i touch the idle screw it will go crazy.

[lubecakes]

Set it back to factory settings, and make sure your carb is fully seated and not broken. If that doesn't help it may be the bearings....did you check or replace them?

[BigEll]

When I start my 2.5, it idles really low but high enough to stay running. As the engine heats up it will idle in the ideal range.

[Traxxas revo20]

yes i have checked them. They have about 1 mm of slack but i figured it would still run.

[Traxxas revo20]

ok. i took it back apart to try and check it out but all is well. but it would idle for about 15 -20 sec and then die. but would start back up. i believe the fly wheel mite of been loose. Is that an issue?

[lubecakes]

1mm of bearing "slack" is an issue.

[Traxxas revo20]

ok, ill order new bearings and try that, thanks guys

[Monte_1977]

ok, ill order new bearings and try that, thanks guys

Those bearings are a bugger and in fact I'm currently stumped on how to remove the inner engine bearing but I watched a video by Squirrel on youtube and he has a HUDY engine bearing remover/installer tool. The tool is almost $100.00 and I about choked when I saw the price. Another method I found was to heat up your oven to 250 to 300 degrees and put the engine in the oven for about 5 minutes but make sure you use an oven mitt unless you like your hands burnt

Heres a link to the cheapest HUDY Engine Bearing Remover/Installer Tool that I could find as used by Squirrel in his video on Youtube https://www.ssl-stormerhobbies.com/c...s&pn=HUD107050

[Monte_1977]

Almost forgot...Just the engine block itself if youre going to use the oven method. No more than 5 minutes or you will cook that bearing. Honestly, i dont like the idea of cooking my engine for fear of burning up that bearing but it can be done and the bearing will come out with the heat expansion when the engine gets hot enough.

[Monte_1977]

Heres the video I watched by Squirrel on youtube. http://www.youtube.com/watch?v=IUD_UBjxkYQ

[lubecakes]

In the oven at 200°-250° is fine, that will not hurt any bearing. Your engine can reach 270 degrees right?

[Double G]

Almost forgot...Just the engine block itself if youre going to use the oven method. No more than 5 minutes or you will cook that bearing. Honestly, i dont like the idea of cooking my engine for fear of burning up that bearing but it can be done and the bearing will come out with the heat expansion when the engine gets hot enough.

??

In the oven at 200°-250° is fine, that will not hurt any bearing. Your engine can reach 270 degrees right?

I'm going with lube on this one. The aluminum block will "cook" well before the steel bearing. Plus if you are replacing the bearing you shouldn't have to worry about damaging it.