RE: best way to tune a monster truck?..
Only you can answer if there is dirt in the throat of the carb, then there must be dirt inside also, DO NOT TAKE THE ENGINE APART UNLESS YOU MUST, even if you see some ( a little dust ) just flush it out with fuel. most likely if you seem to have lost some power it is because of your needle setting, how does the compression feel compared to new ?? for break-in keep temp low at 200degrees F, after 4 tanks of rich running, lean out sightly to maintain a temp not higher than 250-280, check temp often as it will lean out as the engine gets hotter. I prefer to have em set so that when you first start it it seems to rich but after a couple of laps it begins to warm up and run better and temp @ 250.