Hello, I have a SH racing .28 in a 1/8 buggy. I got it the day after xmas. I had a 1/10 truck a couple of years ago but due to my need for speed I was always blowing the motor so I stopped running it. This time I swore I would have a motor last more than a gallon of fuel.


I broke the motor in using the heat cycle method. Then I started leaning out the top end. Before I finished the tuning it was dark. The next day I went to the track with a friend. I finished tuning the top end with the temp at 250. The bottom end was still fat so I went to do it, slowly. Before i got to do it my friend came over and turned it in I don't know how far. The car ran good, idled good and came out of the hole like a demon. I ran probably 7-9 tanks of gas that day.


Now the car has no bottom end at all. It still has good top speed, idles good and doesn't get over 250, but no low end power. I have tried richening it(as far as half a turn out with no difference) and leaning, but nothing changes it.


Is it possible to hurt the low end power without hurting the top? Could it be dirt in the needles? I am at a loss.


Thanks for any replies.

The easiest way to get an idea of where your low speed is at is by using the pinch test. Just pinch the fuel line at the carb and if the engine just dies within 2-3 seconds it a bit lean & if the rpms rise by more than 300rpms or so it may be a bit rich. Alot of people also like to do a wide open pass and then let the truck idle for 8-10 seconds and punch it. You should get fairly clean crisp takeoff. Don't worry about the temprature, as long as its below 280 your fine, some engines(my s-25) love 290-300 even. Tune it for performance and take random temp readings to make sure you don't have an air leak, but not for tuning.

I think I found the problem today. I decided to take it all apart and clean it. I think I had the clutch shoes in backwards. Its to cold today to try and tune it but just running it my garage for a little it seemed like before. Thanks for the help.

I haven't been tuning by temp just posting them for reference. I use the lean it till it doesn't pick up then back off and 1/8 turn.

As far as the pinch test goes does the motor need to ba all warmed up for that to be correct?

Who put the clutch shoe's in backwards.

..........TURNELL..........