Join Date: Feb 2011
Location: New York
Thanked 0 Times in 0 Posts
VM 38 twin carbs settings
okay folks here we go. After eating a piston because the friend that "cleaned" the PTO side carb. didn't do such a god job. Hence the carb ran to lean and ate a piston. Two new pistons later and I'm having an awful time getting the carbs reset.
I removed everything cables and all and took the carbs to my local cat dealer, they did a great job cleaning them, got everything back together. Upon putting it all back realized that everything could or was out of adjustment. Especially since all the settings were mucked around with in the process of the "dirty just cleaned carb on the PTO side"
Sled wouldn't start, why because one of the safety switches was out of alignment. So I disconnected them and ran the sled after adjusting the air idle mixture screw and having to cranking down on the both plungers setting them all the way in. The sled ran good no safety switches rode for at least four hours in total. I've not touch the air mixture screw (main jet) per the dealer. He set it to one and a quarter turn. Book says one on a ZL 550 ESR. I figure hey these guys know. That said to the best of my knowledge that's what they are set too.
Next case back to the dealer to ask do I need a new switch? Basically the lead mechanic said most likely it was throne off either during or after cleaning. Got out the old VOM meter and checked the switch. Its good so it must be the placement adjustment. The same mechanic said I shouldn't have changed the plungers and turned them all the way in. However when I first started the engine it really ran up (high rpms) seemed like the only way to get it to idle down or at least help idle were the plungers. And of course the Idle mixture screws which seem like they are really far out, like five and half turns.
I reset the sync both carbs are good to go, use the two fingers on the plungers method. They are adjusted out about eight turns, I marked one side of each adjuster, using the bottom location once they were in sync to back them out.
I finally got the sled started and it ran high rpm again, backed out the idle screw, got it to run at about 1500 rpm, everything seemed great. Put the belt back on. and boom engine won't start, seems like it only runs in half choke, bogs down as soon as you hit the throttle and won't idle. I did notice that the throttle grip body was loose. How I have no idea, It feels like there is a notch that it hits so I moved it to that position and tighten it.
At this point everything else is like up in the. The shop manuel says to adjust the carb use the setting from the removal the carb page. Brilliant if you were lucky enough to have removed them. I'm open and up to anyone that might have the correct process or procedures.
Thanks in advance.