Ok here is the situation. I bought this machine and it ran like crud(wouldn't idle). Put the new carb on and it runs like a champ but there is a very loud rattle which I believe is coming from the jug. The idle mixture is set 1 1/2 turns out and the compression is around 120. It runs great but I'm concerned about this rattling which sounds like the piston is slapping around. I called the previous owner and he says the machine has never been pulled apart and he never noticed any rattling. I didn't really run it before I went through the carb so I'm not sure if it was doing this before but I'm thinking it probably was. I guess now I'm wondering if this rattling is normal or should be a concern? Any help?
Two strokes tend get worn out and develop piston slap, they are easy to rebuild, bore it and put in a new piston and rings.
08 Arctic Cat Prowler XT M4 Camo, The Big Bad Cat! Racked, 4K winch,108ss/Bighorns and lots more Member: Team Emerson "It Only Costs a Little More To Go First Class! "Team Emerson always picks up the trash"
Gunrunner, I took the head off last night. The head, top of piston and sleeve are all heavily carboned up. However, the bearings seemed fine and there was no play with the piston in the cylinder. I'm confused as to where this slapping was coming from. I did not measure the tolerances because my machinest asked me to just bring the parts in to him. Any thoughts on what was causing this noise?
It could be worn at the skirt of the piston, its hard to tell without micing the cyl and the piston, since its apart, I would bore it and add new piston and rings and be done with it. could also be worn at the wristpin or have bad wristpin bearings, check those too.
08 Arctic Cat Prowler XT M4 Camo, The Big Bad Cat! Racked, 4K winch,108ss/Bighorns and lots more Member: Team Emerson "It Only Costs a Little More To Go First Class! "Team Emerson always picks up the trash"
I'm pretty sure this thing was overheated because I don' think the injection was working right, also the silver part of the crank that you can see looking down in the jug is burnt blue(is that normal?) By hand I could not feel any play in either of the connecting rod bearing except sliding back and forth along the pin. I spun the engine by hand when I got everything apart and there was no rubbing or noise so I'm almost convinced it was in the top end.
08 Arctic Cat Prowler XT M4 Camo, The Big Bad Cat! Racked, 4K winch,108ss/Bighorns and lots more Member: Team Emerson "It Only Costs a Little More To Go First Class! "Team Emerson always picks up the trash"
Good to know. The machinist called me and said the skirt was cracked and the cylinder needed to be bored with oversize piston. Now that I blocked off the oil injection I was told by someone I may have to adjust my air fuel mixture beyond factory(1-1/2 turns out). I'm assuming I would have to go richer because it's not getting as much fluid now? Also, you would turn the screw out to go richer right?
no,its a air screw the more its turned in the richer/less air it will get.
08 Arctic Cat Prowler XT M4 Camo, The Big Bad Cat! Racked, 4K winch,108ss/Bighorns and lots more Member: Team Emerson "It Only Costs a Little More To Go First Class! "Team Emerson always picks up the trash"
