Sparco

i was running my axial .28 earlier today when the engine would only rev to about 1/4 throttle, even though the carb was at WOT, i took apart the clutch and i noticed a weird pattern on the anodized parts (ill post some pics in a bit) does anyone have an idea what my problem might be?

twomanytoys

Sounds like you overheated it if the anodizing changed colors.

Sparco

srry, i meant that it rubbed off in a weird pattern, the shoes are hitting the front of the clutch (on the inside) and wearing away spots on the top of the shoes...if that makes any sense

twomanytoys

Ok sounds like bearings went bad. I had the sme thing happen a few weeks ago. I replaced the bearings and all is good. The bearings in these suck.

Sparco

i just checked, there's some oil on the bottom of the crankcase...and its 7x19x6 bearings i think?

black mamba

Sounds like a clutch problem. Some oil leakage out of the front bearing is normal.

BudBud

I use Picco front bearings in mine, they are sealed in and out instead of just on the outside like the original bearing. They have been hanging in for a long time! BB

Sparco

does the front bearing from an s-25 fit an axial .28? i might scrap em and save a trip to my lhs

mazdab2600

if you mean the front crankshaft bearing.
yes.both use a 607z/607rs bearing. size 7x19x6mm.hpi#1421 or axial #ax034
http://www3.towerhobbies.com/cgi-bin...?&I=LXPEA3&P=7
http://www3.towerhobbies.com/cgi-bin...?FVSEARCH=607z

Sparco

thanks!

runninwild

dont mean to bring this topic back up. but yeah, i have the same problem Sparco did. did you solve this problem by replacing the clutch or replacing the bearing(s) in the motor? and if it was the bearing which bearing was it.

black mamba

CB bearings live a rough life. Run quality bearings for less maintenance.

runninwild

ok im still a noob here.. lol, what is the CB bearing?

black mamba

Clutch bell.

runninwild

ah i see.. i probably have to rebuild the whole clutch assembley aagain anyways. was this sparcos problem?

black mamba

A couple of things could'vd caused it. A CB that wasn't shimmed right would do it-either too tight or too loose, grenaded CB bearings or bearing would do it too. I've had a CB screw come loose and fall off and it let the CB work its way forward and when it did that it chipped the steel spur and CB teeth and it ate up the aluminum clutch shoes. All because I forgot to Loctite the screw.[&:]

runninwild

so im confused. how would this have caused the engine to only rev to 1/4 throttle when its at WOT? now that i think of it the last time i took that apart, one of the bearings on the CB, the cover off one side had fallen off and you could see the ball bearings. i had put it back thinking it was ok... guess not?

black mamba

Losing the bearing shield won't cause any problems per se, but letting it go would.......eventually it would cause the bearing to grenade and or seize as dirt and grime got in it. Then you'd have problems. As for the revving issue, it could've been because the shoes were messed up or something was jamming up. Hard to diagnose without seeing it.