- Messages
- 59
- Reaction score
- 144
- Points
- 108
- RC Driving Style
- Bashing
It's a completely custom build stadium truck with a LRP 28 Spec4 mated with a Jato 2 speed with all Hot Racing steel gears. It was running great. Now for some reason when it goes to shift into 2nd at full throttle the motor bogs down. It doesn't die, if I let off the throttle and give it a little gas it's still running.
I've taken apart the transmission. The 2 speed shift hub looked good. I could pull out the arm with a screwdriver and didn't notice any binding. The one way bearing on the primary shaft would spin freely in one direction and lock in the other. I've got replacements for both on order. I rebuilt the diff topping it off with 10k differential fluid and replaced all the X rings. Checked all the steel gears for damage and they were all good.
Checked the slipper clutch and replaced the pads as they were getting a little bit worn down. Made sure clutch shoes were good and the flywheel nut was tight. I replaced the clutch bell bearings and made sure the clutch bell screw was tight.
Thought it could've been a fuel issue but didn't notice any leaks on the tank or fuel lines but replaced them all to be sure.
After all this I thought maybe the tune was bad. Loosened the 2 speed hub set screw about 3/4 turn just to see if it'd shift right, no dice. Reset the carb back to factory settings, HSN 4 1/4 turn out and LSN 3 1/4 turns out and started to retune the HSN. had to turn the LSN about 1/4 in to get it to actually run so I can drive it. Trying to make some high speed passes. Motor temp got to about 170F before it tried to shift but it did the same thing. I know the motor isn't running lean. It got up to about 190F and when I brought it in at idle I could see the temps start dropping. Steady blue smoke during the whole session and it was still rich as hell.
Main thing I noticed if I carefully give it linear throttle it'll shift, if it's wide open right away it'll bog down. I'm honestly not sure what the issue is anymore.
I've taken apart the transmission. The 2 speed shift hub looked good. I could pull out the arm with a screwdriver and didn't notice any binding. The one way bearing on the primary shaft would spin freely in one direction and lock in the other. I've got replacements for both on order. I rebuilt the diff topping it off with 10k differential fluid and replaced all the X rings. Checked all the steel gears for damage and they were all good.
Checked the slipper clutch and replaced the pads as they were getting a little bit worn down. Made sure clutch shoes were good and the flywheel nut was tight. I replaced the clutch bell bearings and made sure the clutch bell screw was tight.
Thought it could've been a fuel issue but didn't notice any leaks on the tank or fuel lines but replaced them all to be sure.
After all this I thought maybe the tune was bad. Loosened the 2 speed hub set screw about 3/4 turn just to see if it'd shift right, no dice. Reset the carb back to factory settings, HSN 4 1/4 turn out and LSN 3 1/4 turns out and started to retune the HSN. had to turn the LSN about 1/4 in to get it to actually run so I can drive it. Trying to make some high speed passes. Motor temp got to about 170F before it tried to shift but it did the same thing. I know the motor isn't running lean. It got up to about 190F and when I brought it in at idle I could see the temps start dropping. Steady blue smoke during the whole session and it was still rich as hell.
Main thing I noticed if I carefully give it linear throttle it'll shift, if it's wide open right away it'll bog down. I'm honestly not sure what the issue is anymore.
