2000 mountain max 700 bogs out of the hole

bogey

bogey

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Joined
Dec 16, 2011
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13
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nipawin sk
hi i have a 2000 mm700 and it's bogging out of the hole then picks up and goes.

i.ve cleaned the carbs and it's jetted according to the yamaha specs,dropped the needles down one spot, ive taken apart the fuel pump and cleaned it, i put a talller gear in the top of the chain case and have put heavy rivets and a different primary spring, secondary preload is 7,

any ideas?
 
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Dropping the needles leans it out. Usually on these red heads a bog off the hop is lean condition or clutching. I would try a 1/4 turn out on the fuel screws and lift the needle a clip or 2 and see what it does. If it doesn't change, I would start looking at the clutches. A quick way of seeing if it's fuel related it to give it a little choke when it's bogging. Hope this help fellow Saskatchewan guy!
 
Agreed, flip the choke to see if it helps the bog. Lowering the needles is leaner, but don't confuse that with lowering the clip. Best way to think about it is the lower the needle goes in, the less fuel it can flow. Moving clip up lowers the needle = less fuel. Lowering the clip raises the needle = more fuel.
If flipping the choke helps, then try what Taylzee said. I'd do the fuel screws first, and make sure to only make one change at a time. If you were trying to move the needles to get more fuel, then make sure to put them back where they were before.

The other concern is you said you put a "taller" gear on for the drive sprocket. If you put a gear on with more teeth to try to get more top end speed, it may be having trouble getting the track moving now with the higher gearing...kind of like taking off in 2nd gear in a car. Higher gearing will lower the peak RPM's, so it doesn't follow that you also put in heavier weights? Are you getting the correct peak RPM's when at WOT?

So, try flipping the choke first. If that helps, then it needs more fuel. If it doesn't, then gearing/clutching is next. We'll need to know your track length and what gearing/clutching to go from there.
 
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okay sorry what i meant was i moved the clips up one spot to lean it out while idling when i flip the chke on it does clear up,

I put the taller gear in because this sled will never see the mountains or any kind of hills, and the heavy rivets i wanted a lower engagement it engages at 3500rpms

im hittting 8500 to 8700 at wot
 
If the carbs are clean and everything else is stock, put the needles back up to stock. Start with the fuel screws and throttle cable adjustment to get the idle.

As for the clutching, it depends what weights you have in there and where you put the rivets. You can adjust your whole engagement and shift curve by having weight at the tip verses weight at the heal.

You guys have any snow up there? Looking to maybe trailer somewhere over the holidays. It's pretty bad down south for snow.
 
ill try moving the needles back i moved them because it seemed like it was loading up with fuel when idling i have the idle mixture 1 1/2 turns out like what the factory settings say, so maybe should i try turning them out first?

no real snow where i am, giong home for xmas to la ronge sk, theres about a foot of snow there so i guess it s better than nothing

probably going to the mountains this year so ill see some snow at least this year
 
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When I was running my mm700, I think I was at 1 3/4 out, but every sled will be a little different.
What weights and rivets did you put in?
 
cant remember i just went to yamaha and asked for the heaviest they had
weights are stock
 
Stock, I ran 8cr weights with 10.3al tip and 17.2st heal (for 1700`elev). This put me at 8350 WFO. To me you have too much weight in the primary for engagement (4500rpm) which is pushing the belt up the primary and pulling the belt down the secondary too fast.

I ran 1 3/4 on the fuel screws, stock position on the needle and 142.5 mains. I found that by leaving the choke on just a little too long when cold starting, it was easier for them to load up a spit out a plug.

This was all with the stock 21-40 gearing.

What is the gearign you have now?
 
okay so i moved the needles back to the middle sled is still bogging thinking about it when i did do all the work to it , it ran good for a few years just this year it started doing this so i dont know i havent adjusted the idle screws yet im just wondering if it will make that big of a difference turning them out a 1/4 turn more, i put a white silver white spring in the primary as well and the only change this year is put a bender can on it but it was acting up with the stock muffler so im not sure it had a little bit of old gas in it but i put octane boost and filled it with fresh fuel

any thoughts?
 
We've always held that those type of additives (booster, dry gas, carb cleaner) should not be used in 2 stroke outboards because they do not mix properly and cause running issues. I picked up one of those bb shake siphons just so I can drain my tank to start fresh each year, and put in the highest octane I can with sta-bil ethanol treatment incase any moisture got into the tank in storage.
 
SO you did all the gearing and clutching work a few years ago??? If so I would be looking real close at carbs or the clutches for something broken or binding.
 
clutches i had apart and cleaned, carbs have been apart and cleaned everythings good there so maybe ill run a tank of fuel through see if maybe the old gas has something to do with it, i also noticed if i blip the throttle a bit and get the rpms to about four thousand then punch it, it s fine just if i stop and punch it without doing that it bogs out
 
that is a symptom of water in the bowls in an outboard. I've cleaned carbs on small outboards that would sputter along with the throttle wide open for a little while until it would finally catch up with itself.

Pull your airbox and drain your carbs into a clear container and see what the fuel looks like.
 
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