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Discussion Starter · #1 ·
2004 MXZ 600 HO SDI - Here's where I'm at.....

Hoping someone can help me out here. Last week I went riding all day with no issue. Stopped for a bit when we got back, and when I started up again, I fouled a plug. Changed both plugs out with new ones (NGK BR9ECS) and she started up again. Ran fine for the short drive home.

2 days later we pull the machine out, fouled again. Seemed as though no matter what we did, she only wanted to fire on one cylinder. When pulled the plugs, one was wet and the other dry. This time replacing the plugs didn't do anything. At best she was run for a few minutes, but cut back down shortly after.

After some investigation, I noticed the reed valve boot on the clutch side cylinder was ripped across the top. Gata start somewhere, so I bought some new v-force reeds. I did check compression to make sure nothing was damaged, and both sides read 120lbs warm.

Removed the old (stock) reeds and boots, which I later learned were both in rough shape, cleaned the throttle body, and installed the new v-force reeds. Also pulled the exhaust valves out and cleaned them up.

I popped the new plugs back in, and tried to start it -> Nothing. Then I swapped the new plugs out for the old ones I had pulled out earlier (same plugs) . It started, but its as if its running at half power again. Almost sounds like a cleaner version of what it was doing before. Its boggy right from the start now.

Do I / can I adjust the air mixture on this machine? Is there something else I should adjust that I'm missing? If so, how do I adjust that mixture?

I'm still sort of new at this, but I'm learning as I go. Any help appreciated. Thanks.
 

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I talked to a ex doo tech and he said pretty much every time you completely remove the throttle body you gotta get it recalibrated.. aka Tps reset.

I'm gonna do mine this week at dealer
 

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Does it backfire? It sounds like the system is flooding the machine with gas. Mine did the same thing when it had bad intake gaskets.
 

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Discussion Starter · #4 ·
Yes, it was backfiring prior to changing the reeds. Since then, no backfiring. Now I can't even get it to turn over.
 

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Just can't get it to start.cxThere is fuel getting to the cylinder, plugs are wet when I take them out. So I don't think it's the injectors. I confirmed plugs have spark. Could be the tps. I did remove the relay from the throttle body, but I didn't remove the throttle body itself. I lost a bit of coolant when attempting to remove the throttle body, but I ended up leaving it in when I seen how much of a pain in the it would be to remove. Checked and rechecked that everything's back together properly.
 

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Discussion Starter · #9 ·
Could be a weak spark. I have a volt meter. Batt was reading 12.4 last night after multiple attempts to start it (electric start) so I think the bats good. I'm pretty sure the ohmeter part doesn't work. Gonna see if I can get my hands on one to test the coils tonight.
 

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It is impossible to change reeds without taking the throttle body off the boots... And you took the tps off the throttle body... You should be running br8ecs plugs and try cracking the throttle to get it to start
 

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Discussion Starter · #11 ·
Well obviously I took the TB off the boots :) I meant I didn't disconnect the coolant lines, I left it in the machine and worked around it. I was reading on plugs I'm going to pick up br8 ton ight and try that. Thanks for the tips everyone. I'm goig to keep at it.
 

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12.4 volts is a weak battery. Fresh battery has around 12.7 or so. SDIs don't run well with weak batteries. How old is it?
 

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Ya ive read about that. Just measured the batt at 12.36v. That being said, I've been cranking it with the electric start trying to get it running. Starter sounds strong. I'm not sure the age of the batt. Came with the sled when i picked it up two years ago. I imagine it's more than a few years old. Can't get it going with the pull cord either tho. I'm leaning toward a spark issue at this point. It won't even spudder at this point.
 
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