2008 Apex RTX revs at 11,000 rpm at WOT. Normal?

[jgustman]

Just came back from a trip in the UP of MI. Bought the sled last spring and haven't had a chance to open it up until now. 11,000 rpm at WOT at full shift on loose sugary snow. Belt width measures 31.96 mm- so a little wear. 4,200 miles on the sled. Should I replace secondary clutch buttons as they are worn flat but look to have plenty of life left. I read that it can make them over rev. Lastly I noticed the RTX gearing is 2 teeth smaller on the small gear. 22 versus 24 on the regular apex, which could be the issue since clutching is the same otherwise. I think replacing buttons and possibly loosening the secondary 10 deg. may do the trick, but don't want to lose backshift...Also a bit leary of running 11,000 rpm...

 

[blue er]

if i remember 11100 is rev limiter, at max power occours at 10600-10800 on the apex, but also if your loose snow, hard pack, ice all will give you a different rpm, how much track spin ect .
is it the original set up? or aftermarket clutching?

 

[jgustman]

All original clutching, only 144 gold diggers with triangle backers down the middle. I'm just wondering if all RTX's over rev due to lower gearing. I'm sure the belt wear and buttons may be raising rpm's a bit, but could it be that much. I could add a washer to the rivets in the primary weights if need be. It feels damn snappy but only saw 107 on the speedo on the loose snow trail at 5 degrees temp... Are the tach's reading a bit high on these apex's?

 

[Ak Yammy]

I will see 11 on mine but it will usually settle into the 10.8 range once it gets traction. New belt or do the washers on the back of the clutch as outlined in your owners manual. If you feel your buttons are worn then replace them. The different size gears on the RTX were put in for quicker accelleration but make the top a little slower. Shouldn't have to re-gear to get rpm's dowm. Also I wouldn't loosen your secondary I did and it seemed to not backshift as well.

Edit: just read your last post afte posting this: RTX does not run different due to gearing it's in the clutching. First thing I would do is put a brand new Yamaha belt on there and I bet all will be right. 107 in powder is probably normal these machines are slow in any kind of loose snow. Report back if you are getting low speed on the hardpack then there are some things to check.

 

[jgustman]

"Report back if you are getting low speed on the hardpack then there are some things to check"

Ha, that's funny. I don't know when I'll get to test. We had to drive 400 miles to get to ridable snow last week. Got 3-4 inches here at home now, but still not enough in the ditches to ride and it's been so warm here I don't trust taking it on the lake that is 4 blocks away. My neighbor kid told me last week there was only an inch of ice when he walked out and had the auger fall through when he sat it down.

 

[Ak Yammy]

I know you guys are having some low snow down there and warm temps. If it makes you feel any better it's -30f here so here I sit typing away. Well for comparison my 07 RTX (all stock) on a good hardpack run with some space will see 125 on the dremo with a best ever of 128. If yours seems a bit sluggish do the donut rag test to see if they are blown. Also check your speedo bearing, grease bearings including skid wheels. Doing these things along with a new primary spring got mine up about 10mph from when I first bought it as a used sled. Lil Seafoam in the tank never hurts either.

 

[grader]

your belt is at its wear limit of 32mm. change it out for a new one and your rpm will drop and your speed will come up.

 

[jgustman]

I must have been drinking when I gave the belt width measurements. I believe it was 33.96 or 32.96. New is 34.5 mm I believe... I better re-measure... I've greased all the bogey wheels and bearings about 400 miles ago when I revalved the rear skid. 2-4 inches of snow is suppose to fall tomorrow, so hopefully I will get to ride...

 

[sherlock29]

I see 11 with my 07 RTX.... its normal... because of lower gearing... rev limiter is around 11,200 (i've hit it under WOT over "woops").. dont like too but it has happened...

 

[jgustman]

I know you guys are having some low snow down there and warm temps. If it makes you feel any better it's -30f here so here I sit typing away. Well for comparison my 07 RTX (all stock) on a good hardpack run with some space will see 125 on the dremo with a best ever of 128. If yours seems a bit sluggish do the donut rag test to see if they are blown. Also check your speedo bearing, grease bearings including skid wheels. Doing these things along with a new primary spring got mine up about 10mph from when I first bought it as a used sled. Lil Seafoam in the tank never hurts either.

-30. Not Fun. The two days we rode in the U.P. last week, the morning temp was -25 thurs, and -20 friday. Kinda sucked. Glad the sled started, it died twice starting it the first morning, but didn't flood.
I forgot to add the jackshaft bearings and donuts are new at 3800 miles done by dealer when I bought it...Has about 4400 miles now. Also already had a snostuff rumble pack muffler when I bought it-maybe adds a few hp. Don't need springs, they need to be softer to pull rpm down if the belt and buttons don't do the trick, or add fly weight. If this 11,000 thing is normal on the RTX, I'll be adding weight. or getting a lighter finish rate primary spring. Problem with springs is that I don't know how much rpm with drop, say with a 10# lighter finish rate??? I'm guessing drilling out the rivets and adding a washer is probably the cheapest solution.

 

[Ak Yammy]

Little more info: http://www.ty4stroke.com/viewtopic.php? ... 5a2b168d1b

Sorry do not agree the high rpm's are unique to an RTX due to lower gearing. Even rode with a Gt that was doing the same thing at 11.

Mine set up basically like Knapp's will pull 11 in softer snow if I punch it but will plane out at 10.8. Says limiter is at 11.25.

 

[jgustman]

Good info. I'll stop worrying then. I didn't know there was a newer -01 belt... I also read a few posts stating the pink secondary spring can bind before full shift out, causing over rev. I noticed that it occasionally "rarely" doesn't backshift if you get on the brakes and back on the throttle at slow speeds. Looks like try a new belt and secondary buttons since they have 4400 miles and maybe polish the secondary ramps.

 

[sleddog66]

Mine will run 11000 now with excell header. Was 10,800 stock. 11000 is on top os factory spec.

 

[jgustman]

I was wrong about my current belt width. It is 33.9 mm. So not much wear. I believe the added hp from the exhaust and worn clutch buttons are my main culprets. But the very cold air that day may have given some extra ponies too.