2000rpm hump

[avionicsman]

the engine has a HUMP to get over at 2000rpm. It does'nt want to slow down below 2000, even when i'm driving & pull the clutch to shift the engine maintains it's rpm, won't slow down between shift's. When I come to a stop I must drag it down under 2000rpm w the clutch. Then it will idle nicely at 1300rpm. To get going again I must rev above 2k and slip the clutch using plenty of power. only mods are a DG and 12.5 compression pistons. Runs a little rough but ok. Ever heard of anything like this?

[daves79x]

Could be timing, but far more likely the carbs. Not clean, not synched, or both. Lots of threads here about the subject.

Dave

[avionicsman]

well i finally broke down and got the 6gauge setup and synked the carbs, now it runs better, it actually slows down between shifts & idels good. Daves79x was right about that! Still when clutch is pulled in it will slow to 2000rpm, then i must drag it down in gear to below that & then it will idel at 900rpm. is the book right about compression 170? i'm reading a low of 110 to a the highest cyl of 155 & thats w 12 to 1 pistons! what do you think of that? Curtis in Fla.

[avionicsman]

is it better to run the blowby tube down to the ground? or into the airbox , any advantage to makeing the engine run smoother?