14 Pro bog at 7200 rpm

[200smk]

Hi Guys,

Finally got the sleds on (marginal) snow this weekend....have a 14 Pro that has been flawless....oil pump turned up, MDS clutching. New plugs/wires/caps last year BR9EYA.

Sled would bog/fall flat at about 7000-7500....replaced plugs, no difference. It seemed like it was hitting a rev limiter the way it would fall flat....everything else about the sled was good...idles fine, starts fine, reverse fine, good power up to 7000.

Looking for a little help on where to start....it has not had the TPS checked, that was going to be my first item to check....

Thanks for the help!

 

[live2beel]

Fuel filter.

 

[RoostinRyan]

Fuel filter.

This is what I would do first. Also I was having similar issues and found carbon built up in my ves ports in the cylinder. My sled runs flawless after doing these two things.

Mine was acting like it was bouncing Rev limiter but lower rpm.

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[200smk]

Hmmm......good call on the carbon in the EV ports. I'll try that.....fuel filter has been changed recently.

 

[RoostinRyan]

Hmmm......good call on the carbon in the EV ports. I'll try that.....fuel filter has been changed recently.

I used a small paper clip and cleaned them out really good, making sure the paper clip went all the way through. Then did the same with the ports on the valve itself making sure they were totally clear. Good luck!

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[200smk]

Well....cleaned the valves (weren’t bad), got in the ports with pipe cleaners and worked them good. Tried the sled on a stand and it seemed like it was clear, revved nice and crisp. Tried the sled on the snow, still bogging at 7500-7800.

Added a little weight to the clutching to rule it out...no change still bogged.

Worked the tss and it’s seems fine.

I’m lost on this one, everything else about the sled is normal, starts 2nd pull, idles about 1700, power is all there.

 

[Sheetmetalfab]

Sticky or flat spot on a primary clutch roller?

New belt?

Worn motor mounts?

Loose engine strap bolts? (Bottom of engine)

 

[200smk]

Primary rollers spin fine while changing weights.
Belt has about 1000 miles on it.....but my issue is that when the sled hits 7700ish rpms it really feels and sounds like a rev limiter....that type of sound/feel.
2400 miles on sled, has had SLP torque stop since new, motor mounts don't look bad.

 

[200smk]

So....just thinking about that 1000 mile belt...could it be that the worn belt is slipping at high rpm causing it to ping the rev limiter every time??

 

[RoostinRyan]

So....just thinking about that 1000 mile belt...could it be that the worn belt is slipping at high rpm causing it to ping the rev limiter every time??

I'm not so sure. I'm running the belt that came on mine and it's got 2700ish miles on it. Maybe I've just been lucky.

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[RoostinRyan]

I would start looking into things like spark. Checking wires etc. I wore through another set of wires this year from them rubbing together. Just something else to look at

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[Sheetmetalfab]

So....just thinking about that 1000 mile belt...could it be that the worn belt is slipping at high rpm causing it to ping the rev limiter every time??

For reference I replace / rebuild clutches at 500 miles.
(Everything can look and feel good but swapping the clutch yields instant performance gains)

Typically belts are 300-400 miles until they don’t hold rpm.
Clutch springs every 300 miles for primary.


Check into loose / rubbed wires as mentioned above also.

 

[Teth-Air]

Check pipe springs and for cracks in the exhaust.

 

[Super Dave3]

Those are the wrong sparkplugs they should be projected tip. I don't think plugs are the problem. Try putting the stock muffler back on and see what it does.

 

[200smk]

I’m using br9eya plugs recommended by TRS. Fuel filter was replaced last year. Plug caps and wires were replaced last year. Put a couple good rides on these last year and all was good. Problem has only been since pulling out of storage.

2400 miles on sled probably half on the current primary spring, original secondary. Clutches have not been rebuilt. Half mountain half flatland riding.

The bog sounds to me like a rev limiter or the exhaust valves cutting out....exhaust valves are clean, but could something ‘in front’ of the EV’s be causing it? Hoses plugged, solenoid thing plugged...

 

[XCaSSAULT]

You say problem started out of storage. Have pulled the old gas and added good new gas? Or at least burned the old and are on a new tank. Other out of storage problems could be rodent chewed wires, corroded ground or other wire connections, or dry rotted hoses on ves system. Also check ves springs and bellows

 

[200smk]

Yep, new gas. Hoses, bellows looked good. Wires don’t look chewed anywhere, haven’t checked ground yet....thinking wires/ground would affect at all ranges, not just high rpm. Everything about the sled feels normal....

 

[XCaSSAULT]

Yep, new gas. Hoses, bellows looked good. Wires don’t look chewed anywhere, haven’t checked ground yet....thinking wires/ground would affect at all ranges, not just high rpm. Everything about the sled feels normal....

Not necessarily, more throttle puts more load on all systems and a bad ground doesn’t mean it’s not grounding at all.

I took a sled to the do it yourself wash one spring and de-greased everthing, got under hood all shiny new. The next fall I opened the hood and it was a giant crust ball of corrosion. Now I spray everything down with wd-40 before storage. Have u checked compression?

 

[94fordguy]

Did you ever figure out the cause of your bog?

 

[200smk]

Not Yet.....Dealer has had it for almost 3 weeks. Been too cold to get out and test run....snow is crap here so no pressure to get it done (from me). Hoping they'll get to it in the next week or so.