mnlarge
Newbie
- Joined
- Aug 26, 2006
- Messages
- 2
Well I fired up the old sled this weekend, and I got a problem. The sled started and is running crappy. I thought it was the plugs again and changed out the plugs and that did not help. What I have found is the the 2 MAG side cylinders are not running. I have confirmed this by pulling the electrical lead to the coil each cylinder. The 2 PTO sides are running, as the engine will stop by pulling one of them, and engine will stay running with pulling the 2 MAG side wires. I have checked spark by pulling coils and grounding them out to the frame. I have check fuel by swapping the fuel pump outputs. Nothing has made a difference.
Any suggestions as to what could be the problem?
MNlarge.
Any suggestions as to what could be the problem?
MNlarge.
sled
What kind of sled is it?
What kind of sled is it?
These are prone to plugging the pilot jets, as they are very small, I would clean you carbs. Unless I misread your post and you don't have spark on those two cylinders.
craze1cars
VIP Member
I'm not a Yami expert, but all engines need spark, fuel, and compression to run, so I'll keep this generic:
You say you checked spark but didn't tell us the result of your check. Was there any spark? On all four, or just the two? I will assume you have spark on all four. This rules out ignition prob. But your method is suspect. Pulling the coils? Usually to check spark you pull the plugs themselves and ground them. You need to check this to make sure the plugs are actually sparking, not just the charged coils. As long as you're there, what to the plugs look like? Oil fouled? You might just have last season's fogging oil preventing combustion in there. Fuel fouled? Might just be flooded on two cylinders...
Your method of checking fuel by swapping inlet hoses will only tell you the fuel pump is functioning, but not if the fuel is getting through the carbs....
So I'd suspect if you have spark on all 4, and assuming you have compression on all 4 (have you checked compression?), then it's clearly a fuel problem.
95% of the time this is caused by carbs that need to be cleaned. I'd guess the PTO carbs are plugged up somehow with bad gas. I'd start by disassembling and cleaning all carbs....but only after making sure that all 4 spark plugs are actually sparking. I'll add that plugs are cheap, if it's been more than a year, take the opportunity to replace them and your problem may be magically solved without doing anything else.
You say you checked spark but didn't tell us the result of your check. Was there any spark? On all four, or just the two? I will assume you have spark on all four. This rules out ignition prob. But your method is suspect. Pulling the coils? Usually to check spark you pull the plugs themselves and ground them. You need to check this to make sure the plugs are actually sparking, not just the charged coils. As long as you're there, what to the plugs look like? Oil fouled? You might just have last season's fogging oil preventing combustion in there. Fuel fouled? Might just be flooded on two cylinders...
Your method of checking fuel by swapping inlet hoses will only tell you the fuel pump is functioning, but not if the fuel is getting through the carbs....
So I'd suspect if you have spark on all 4, and assuming you have compression on all 4 (have you checked compression?), then it's clearly a fuel problem.
95% of the time this is caused by carbs that need to be cleaned. I'd guess the PTO carbs are plugged up somehow with bad gas. I'd start by disassembling and cleaning all carbs....but only after making sure that all 4 spark plugs are actually sparking. I'll add that plugs are cheap, if it's been more than a year, take the opportunity to replace them and your problem may be magically solved without doing anything else.
black john
TY 4 Stroke Guru
runing
allso i would pull the coils and clean them with break clean. if they are shorted out with carbon the same thing will happen. this is allso a normal thing to check.
allso i would pull the coils and clean them with break clean. if they are shorted out with carbon the same thing will happen. this is allso a normal thing to check.
