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Discussion Starter · #1 ·
Okay, so if you caught some of the other threads, I've been rebuilding this machine and I'm at the point of putting the carbs back on after cleaning them.

Looking at the carbs I ran into a couple issues, so decided to stop and try to reason this out.

First thing, this sled is new to me, and it has been rebuilt previously. When I got it, the Mag piston was melted on top and pitted the head. When I took it apart, I found several issues that could have caused the meltdown, but nothing really solid.

Right now, I've got the carbs back off because one of the slides wasn't seating properly. I dismantled it and discover the needle was interfering with the throttle cable seating properly. That was an easy fix, but noticed that the clip was in the bottom position. Looking up specs on the carbs, found that was incorrect, and checked the specs on the main jets and discovered they were not the stock ones either.

On this machine, the service manual saying 340/350 and both carbs had 380's. I can't think of any reason why someone would put larger jets in a Summit.

Any thoughts? Or does anyone know if there was a service note about this machine?

I haven't re-pulled the pilots out to see what size they are. I will do that tomorrow. The needle jet and jet needles are correct.
 

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According to the spec book (which should contain any updates) you are right about the main jet sizes. I did notice the plain 98 summit 670 came with 380/370 main jets, so that could be why the PO put in larger jets.

Think Snow!
 

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Discussion Starter · #3 ·
I thought of looking up the '98 specs but didn't get around to it. PO did say it was a 1998. Pretty sure he just read the mfg date on the tag.

PO was apparently thinking he was having carb issues as the machine came with an extra carb. It has a 340 jet in it.
 
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