20hp honda surge up down

[green1advantage]

ok what it is is a pug i understand its made by cubcadet ,its a 6 wheeler 4 drive wheels 20 hp honda air cooled with about 170 hours .
it has from what the maual is a remote throttle eng surge up down at idle the govener is what seems to control eng speed goes way up then almost dies then up down .plugs were changer at 117 hours but changed them any way no change thought maby water in carb pulled it cleaned out with part cleaner reinstalled no change (was no build up in float bowl float seemed good neddle seemed free up and down )
any one have any ideas im really scratching my head

[Restrorob]

With the engine running (surging) start applying the choke SLOWLY, If the surge goes away you either missed a port/jet in the carb. while cleaning or there's a possible vacuum leak. Carb. mount/intake gaskets ?

[green1advantage]

THE CARB MOUNT BOLTS ARE TIGHT I SPRAYED PARTS CLEANER around hoses no change but i was thinking the gaskets on the intake that i cant get to with out pulling side cover .when i get it up to speed with a load dont really notice it ,but when not under load even with rpms raised it still does it when i pulled the plugs they did have a slight white color

[Restrorob]

Well, We sold two of these 6X4 units so I know what your talking about. If it were me I would go back into the carb and do a another clean making sure to spray carb & choke cleaner with the little straw through ALL ports/passages and jets making sure they are all open. All it takes is one small partical of trash....

[green1advantage]

well whatr ill try then is try to spray around the intake at the heads if i get no rpm change ill pull carb and reclean /blow out disassemble and see if i get anywhere .
rob thanks alot and ill repost after i give it a try