05 M7 questions

[Mare]

We have 2 M7. Mine is a 2005, Hubby's is 2006. Everything else is the same MBRP stock pipe. 153 ". Frog Skinz on both sleds. They came with factory stock clutch weights...68's. We talked to the dealer and they said for around here to run 75's. OK, we put 75's in and his sled runs great at any RPM. Mine runs like crap... about half throttle it starts to spudder, and cant take it to full throttle.

I cant keep up with him and I say I cant get the sled to GO any faster... I do weigh about 60LBS more than him, but I cant see that causing it. A few weeks ago, I had an oil issue due to the cable coming off the oil pump, causing excessive oil to flow through. Fixed that and I changed the plugs thinking they may be the cause... nothing changed.

So my 2 questions are...1) Are 75's OK for around here?
My neighbor has a 05 M7 and runs 70 or 71 all over, here and in the mountains. What do you suggest for weights for around here and for the mountains?

Second question.. What things can I do to figure out the spuddering issue?

Any help is greatly appreciated....Thanks in advance... :d

 

[slomo]

the 05 fuel map is extreamly rich and with the 75's are probably loading the motor too much causing a rich bog,drop to 70's and you should be good also change the plugs after a plug starts to foul they rarely come back,i also have a a/c race dept mapped ecm square symbol
for an m7 that was too lean for my m7-800 big bore that i would trade for your 05 ecu if interested and you could try it out first if you like wiht your 75g weights in there

 

[RTTTTed]

So the engine ran like crap due to excessive oil injection? You fixed it and switched the plugs and no change? Obviously you didn't fix the problem.

Try new plugs again, try a .032" gap. Is your sled smoking excessively? Injectors stuck? One plug crapping so 1 black spark plug?

Damaged wires? Coil crapped out?

I would start switching parts between sleds until I found the problem. My daughter's sled runs spectacular.

 

[RTTTTed]

I think that this is probably your problem.
https://www.snowandmud.com/forum/f456/any-ideas-what-might-wrong-my-43234.html

There seemsto be a few Power Valve Cables that have broken. Easy to undo the 2 bolts holding in the power valve on each cylinder and give them a tug.

Supposed to clean the Power Valves every year at the least. they might be stuck.

 

[Mare]

So the engine ran like crap due to excessive oil injection? You fixed it and switched the plugs and no change? Obviously you didn't fix the problem.

Try new plugs again, try a .032" gap. Is your sled smoking excessively? Injectors stuck? One plug crapping so 1 black spark plug?

Damaged wires? Coil crapped out?

I would start switching parts between sleds until I found the problem. My daughter's sled runs spectacular.

It DID smoke a lot before. Then we found the problem, which was the wire, fixed it, changed the plugs. After that it did NOT smoke anymore. Oil usage is same as the 06 sled now.

It runs great until half throttle, then, under load, it spudders at half to full throttle. I have someone looking at the sled this weekend, but was hoping to have this figured out sooner, so we can ride insteed of working on it... :d

 

[Mare]

I think that this is probably your problem.
https://www.snowandmud.com/forum/f456/any-ideas-what-might-wrong-my-43234.html

There seemsto be a few Power Valve Cables that have broken. Easy to undo the 2 bolts holding in the power valve on each cylinder and give them a tug.

Supposed to clean the Power Valves every year at the least. they might be stuck.

I will check this out... Thanks:d

 

[calgarysledguy]

I would pull your pipe off. Pull the cover on the servo motor. Take clips off that are holding cable on. Grab one end of the cable with one hand and then grab the cable housing with the other. Pull it and see if you hear the power valves opening and closing.This will take a little effort but you can pull it buy hand.Then you know your cables are good and your power valves or cables arnt sticking.

With those cables off. Use a digital caliper gage. Check the cable length.should be 34.5mm.There is a diagram that shows you how to do this about half way down the page. It says for 800/1000 but to show you how to measure them. Hope this helps you. Cheers

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