Hey guys, my first post on here, did alot of searching and found tons of good info but not exactly what i was looking for, i also have a pdf of the manual for this sled but also failed to show me what i was looking for.
So i just picked up an 01 mm 700 with few mods, carbon fiber reeds, slp triple pipes, 144 track, and some other goodies but i bought it knowing there is no compression in one cylinder.
Got it home and tore it down and one of the pistons melted down pretty good, dome looks good so i dont think it is a lean running condition that caused it, i think it is lack of lubrication. So i ordered all my rebuild parts but obviously i need to figure out what caused this problem in the first place.
Looking down into the crank case on the clutch side i can see the oil injection hole in the bottom facing up, i disconected the oil line from the fuel pump and can blow freely through it and it comes out the hole in the crank case.
Moving to the middle cylinder, i can see the oil injection hole near the top of the crankcase right beneath the intake, facing downward slightly, can barely see the line feeding it down below on the back of the block, havent got to it yet.
Moving to the far end cylinder(this is the one that melted) i cannot see an oil squirter port anywhere at all! I also cannot see the oil line on the back of the block.
Can someone please confirm where the oil squirted port is located in this cylinder please? Any other idea as to how this could happen would be great, both other cylinders and pistons look great. I plan to remove the oil pump and all the lines and inspect as i think the issue lies somewhere in that area.
Thanks
Robbie
So i just picked up an 01 mm 700 with few mods, carbon fiber reeds, slp triple pipes, 144 track, and some other goodies but i bought it knowing there is no compression in one cylinder.
Got it home and tore it down and one of the pistons melted down pretty good, dome looks good so i dont think it is a lean running condition that caused it, i think it is lack of lubrication. So i ordered all my rebuild parts but obviously i need to figure out what caused this problem in the first place.
Looking down into the crank case on the clutch side i can see the oil injection hole in the bottom facing up, i disconected the oil line from the fuel pump and can blow freely through it and it comes out the hole in the crank case.
Moving to the middle cylinder, i can see the oil injection hole near the top of the crankcase right beneath the intake, facing downward slightly, can barely see the line feeding it down below on the back of the block, havent got to it yet.
Moving to the far end cylinder(this is the one that melted) i cannot see an oil squirter port anywhere at all! I also cannot see the oil line on the back of the block.
Can someone please confirm where the oil squirted port is located in this cylinder please? Any other idea as to how this could happen would be great, both other cylinders and pistons look great. I plan to remove the oil pump and all the lines and inspect as i think the issue lies somewhere in that area.
Thanks
Robbie
edunn69
VIP Member
The oil is "injected" into the fuel pump, mixed with gas, then sent to the carbs where it goes into the motor.
I would start by looking to see if the carbs are clean.
Post some pictures of the damage for a better guess at why it happened.
I would start by looking to see if the carbs are clean.
Post some pictures of the damage for a better guess at why it happened.
I figured it probally would work like that but when i saw the squirter holes in the crank case of two cylinders i assumed it mixed in the combustion chamber, so are these ports in the cc strictly for lubing or what?
Carbs are nice and clean, checked all the jets each carb is running a 145 and 57.5 and none are clogged, havent checked the clip position, are these ok jets for riding anything under 6k ft?
uploading some pics now
thanks for the reply
Carbs are nice and clean, checked all the jets each carb is running a 145 and 57.5 and none are clogged, havent checked the clip position, are these ok jets for riding anything under 6k ft?
uploading some pics now
thanks for the reply
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Backwoods M Max
New member
Did the sled have a bender direct oil injection kit put on it? I have seen them on their site but haven't found much else about them. The kit picture shows 3 tubes and some fitting to re plumb your oil pump to shoot oil directly into the block. They don't publish their instructions online so I don't know where you put the tubes or anything like that.
I had thought about buying the kit myself but I won't buy anything like that when I can't look at the manual first to get an idea how I would install it.
I had thought about buying the kit myself but I won't buy anything like that when I can't look at the manual first to get an idea how I would install it.
Backwoods M Max
New member
I have also read that when you switch to a triple pipe setup your rich cylinder is suppose to be swapped from the pto cylinder to the mag cylinder. If all 3 carbs have the same jet that might be your problem right there.
Backwoods M Max
New member
You also are going to want to check the crankcase seals, if the seal behind the mag is bad it will cause issues with that cylinder to run lean. I lost the motor in my bored out 86 Indy 600 because the pto seal was bad, I didn't understand the symptoms of it, and the piston became a pile of aluminum mush.
Sorry to interrupt guys but could this be from a cold seize
Thanks for the info backwoods, I think you may be right about the bender injection kit, but what is still strange is that I cannot see a port in the mag side cylinder, wonder if the dumb *** didn't install it.....I did some research on the kit and if my motor does have the kit installed I will just remove it all and go back to stock.
I will definetly check the crank seal for any leaks but this really doesn't seem like a lean running cylinder, dome looks fine and so does the spark plug and head, really looks like lack of lubrication.
As for the rich cylinder issue, your saying that on a stock pipe setup the rich cylinder is the clutch side one but once piped it becomes the mag side cylinder? So I would need to jet the mag side cylinder different than the rest?
As for it being a cold seize, the po told me he got the sled completly warmed up before he rode it and then about 5 miles into a ride it lost all power and wound down and wouldn't turn over(siezed the one cylinder) then after it cooled it would turn over but not run. He admited to not riding it lightly but he says it was definetly warmed up completly. And I haven't herd of this this being to much of and issue on the stock pistons as much as with the wisecos.
I will definetly check the crank seal for any leaks but this really doesn't seem like a lean running cylinder, dome looks fine and so does the spark plug and head, really looks like lack of lubrication.
As for the rich cylinder issue, your saying that on a stock pipe setup the rich cylinder is the clutch side one but once piped it becomes the mag side cylinder? So I would need to jet the mag side cylinder different than the rest?
As for it being a cold seize, the po told me he got the sled completly warmed up before he rode it and then about 5 miles into a ride it lost all power and wound down and wouldn't turn over(siezed the one cylinder) then after it cooled it would turn over but not run. He admited to not riding it lightly but he says it was definetly warmed up completly. And I haven't herd of this this being to much of and issue on the stock pistons as much as with the wisecos.
Backwoods M Max
New member
I can look up the specs in the manual for stock jetting with a single pipe when I get home and post for you. What I have read is that the pto cylinder has a bigger jet because the load is right there because of the clutch. Try and find the jet charts for the bender pipes and see what it should have had in it and go from there.
That would be a stupid mistake if the po did buy the direct injection kit and only put it in 2 cylinders. If that's the case you'll have a sweet sled with a fresh motor once you get it back together!
That would be a stupid mistake if the po did buy the direct injection kit and only put it in 2 cylinders. If that's the case you'll have a sweet sled with a fresh motor once you get it back together!
Also does anyone happen to know if all the coils fire at the same time or if they sequential firing according to the cylinder?
I will see if I can find a jet chart, I did check all the jets and they are all the same.
Forgot to mention, the main oil line that runs into the fuel pump is still hooked up I think...at a glance it almost looks like he was running the injection and the stock fuel pump...I will tear into it a bit more tonight after work and take some pics.
Forgot to mention, the main oil line that runs into the fuel pump is still hooked up I think...at a glance it almost looks like he was running the injection and the stock fuel pump...I will tear into it a bit more tonight after work and take some pics.
Mysledblows
VIP Member
Been a while since I've had one out/apart, but I'm pretty sure that there are two injection lines spots to the lower case on the sx motor. Lubes the bearings. Without looking at it, sounds yours is still factory. Might want to look at a online fiche and see what it looks like to be sure. SLP has jetting info on their site. Usually is pretty close - might be a touch conservative.
Ok thanks bud, what is weird is that i dont see an injection hole on the mag side crankcase, but both others i can see. Will find out for sure tonight.
Backwoods M Max
New member
Not sure about the coils, I can look that up I'm the manual too. Might want to check out the crankshaft bearings best you can on that mag cylinder just to make sure they don't give you problems once everything is back together.
sleddineinar
VIP Member
The oil port for lubing the bearings on the mag side is under the bearing itself. Is there an oil line that runs to your fuel pump. If so, that is your oil mix, If the piston wasn't getting oil, it's because the carb was dirty.
Ok I think it is all stock after looking at it some more, I took some pics I just gotta figure out how to get them off my phone that has a broken screen again as of this evening lol.
I removed the oil pump, and put a drill on it and spun it pretty fast and barely any came out, feed hose dumps oil if I remove it so I know the resevoir and feed line is ok, I should see oil coming out if holding the pump wide open an d spinning the shaft with a drill correct?
I removed the oil pump, and put a drill on it and spun it pretty fast and barely any came out, feed hose dumps oil if I remove it so I know the resevoir and feed line is ok, I should see oil coming out if holding the pump wide open an d spinning the shaft with a drill correct?
sleddineinar
VIP Member
Yamaha oil pumps usually fail wide open, so I've never tested them that way.
That's what I keep hearing but I just tryed again, wide open the drill was spinning 2500rpm, tryed forward and reverse and open and closed and got nothing at all out of it...
luv 455
New member
That damage looks like it could be a lean seize which would start at the exhaust port then work its way around but it looks more like there was little to no cooling of that cylinder and it over heated. i would also check the water pump and the rest of the cooling system for possible blockage.
Backwoods M Max
New member
Did you bleed the oil pump prior to testing it?