9000 rpm...

N

NorthernSX

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OK, I have a bone stock 1997 700 SX with 1400 miles.

Hasn't been ridden for 8 years. Took it and gave it a thorough going through.
cleaned carbs, replaced needle and seats, checked center to center, ect.

First ride out, with 8CH belt that was on it, noticed it revs to 9000 RPM and stays there.
Took both clutches off and inspected. Both are 100% stock with stock settings.
Little to no wear on anything. (1400 miles)
Both clutches slid smoothly.

So, I had a brand new 8DN belt, also sanded primary sheave thinking belt may have been glazed.
2nd day out, exact same thing. 9000 RPM steady.

Any ideas ?
Book says its suppose to be at 8300 stock.

Only changes I made were adding a bender silencer and may have taken shelf out of airbox.
Cant imagine those 2 things would cause a 700RPM over rev.
 
believe it or not it does make a diiference with the air shelf removed ...you are leaning it out . put it back in and try it again.also wrap the sec . to 70*
 
yammy said:
believe it or not it does make a diiference with the air shelf removed ...you are leaning it out . put it back in and try it again.also wrap the sec . to 70*
Click to expand...

That would increase RPM, as stock is suppose to be 60
 
I have the exact same sled as you, mine has 2600 miles on it and I also run the 8DN belt. Was out on a 100 mile trip yesterday and opened her up a few times and mine also was at 9000 rpm. It is also bone stock except for the belt. I did replace the primary spring as I have some slip on take off and I can smell a bit of rubber. I will be ordering the heavier rivets that they started to use in 98 when they changed to the 8DN belt. Please post what you come up with as I am interested to see what a fix for you will be.
 
My sled ( 700 Venture) had the same issue as you guys. It would Rev 8800 to 9000rpms. My fix was to add 4.5g rivets with two 6mm washers to each weight tip in my primary clutch. (total of 2.8g heavier at each tip then stock) It droped my rpms by almost 500rpms, and the sled pulled stronger afterwards . An easier way to duplicate these results would be to use a bit weaker primary clutch springs to mimic simular results as adding more tip weight. Both methods will "Load" the engine more and will drop your WOT rpms.
 
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4wealn said:
I have the exact same sled as you, mine has 2600 miles on it and I also run the 8DN belt. Was out on a 100 mile trip yesterday and opened her up a few times and mine also was at 9000 rpm. It is also bone stock except for the belt. I did replace the primary spring as I have some slip on take off and I can smell a bit of rubber. I will be ordering the heavier rivets that they started to use in 98 when they changed to the 8DN belt. Please post what you come up with as I am interested to see what a fix for you will be.
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Will do, but, I had the exact same thing with the factory 8ch belt, so it can't be the issue
 
Vincent said:
My sled ( 700 Venture) had the same issue as you guys. It would Rev 8800 to 9000rpms. My fix was to add 4.5g weighs with two 6mm washers to each weight tip in my primary clutch. (total of 2.8g heavier at each tip then stock) It droped my rpms by almost 500rpms, and the sled pulled stronger afterwards . An easier way to duplicate these results would be to use a bit weaker spring in your primary clutch springs to mimic simular results as adding more tip weight. Both methods will "Load" the engine more and will drop your WOT rpms.
Click to expand...
Vincent, did your sled always rev like that ? Or just start doing it out of the blue ?
 
NorthernSX said:
Vincent, did your sled always rev like that ? Or just start doing it out of the blue ?
Click to expand...

Baught it used with 9000kms 3 years ago, so I don't know
If it always did it, but I've read a few posts on here saying all the redhead triples over rev in stock form.
 
Vincent said:
My sled ( 700 Venture) had the same issue as you guys. It would Rev 8800 to 9000rpms. My fix was to add 4.5g rivets with two 6mm washers to each weight tip in my primary clutch. (total of 2.8g heavier at each tip then stock) It droped my rpms by almost 500rpms, and the sled pulled stronger afterwards . An easier way to duplicate these results would be to use a bit weaker primary clutch springs to mimic simular results as adding more tip weight. Both methods will "Load" the engine more and will drop your WOT rpms.
Click to expand...

I am just in the process of ordering the rivets that the 98 VMAX used with the 8DN belt and I will see if that fixes my rubber smell and also the high RPM. My current rivets are the 13.3mm inner and 10.3mm outer. I am changing them to 13.9mm in both inner and outer just like the 98 VMAX 700 SX is setup with the 8DN belt.
 
Just a heads up if you are ordering rivets.
Yamaha sports plaza has them for 1/3 the price of most places
 
no, that would put more preasure on the belt which in turn would grab better puling the rs down! less grab = less drag
 
yammy said:
no, that would put more preasure on the belt which in turn would grab better puling the rs down! less grab = less drag
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You have it wrong my friend, more wrap on the spring increases rpm because it's harder to move the sheave.
Less wrap loads down clutches because it allows a faster shift.
Maybe someone can give their 2 cents in the matter ?
 
I had the same problem with 2 sleds this year. Leave everything on both clutches stock, replace belt, shoes and both bushings in secondary. One of my sleds was reving to 9200 and the other to around 8900, now both seem to be at around 8300-8500 RPM's.
 
shaggyzr2 said:
I had the same problem with 2 sleds this year. Leave everything on both clutches stock, replace belt, shoes and both bushings in secondary. One of my sleds was reving to 9200 and the other to around 8900, now both seem to be at around 8300-8500 RPM's.
Click to expand...

That is a good point. Doing a very therough clutch inspection and replacing all worn parts is certainly good advice. I did the opposite, added weights to the weight tips, and then the next season I replaced every bushing and wearable part in both primary and secondary clutch. Certainly the wrong way of doing things, I agree. But things worked out and I don't recall my rpms changing much after the clutch overhaul.
 
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backofthepackjack said:
why don't you guys try the free things you can try first.unwrap your secondary 10degrees on your helix, see if it helps bring your revs down a bit from 9000
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I had tried this idea before adding more weight to my primary. Went from 70 down to 60 and also 50.
I lost 100rpm @60 and 200rpm @50 , but I was still over revving at 8700 to 8800rpms WOT and my machine felt very lazy because of the slower backshifts.

Certainly worth a try but for me it didn't work out.
 
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im in the same boat right now, I freed up a few ponies with a holtzman tempafloe and im also hittint 9 or 91 and im wondering the most efficient way to use these few ponies.
I guess unwrapping the helix a few degrees has only small improvments on wot and I was hoping not to lose the awesome backshift the v max is now . what do you gurus think the logical step would be

PS im trying to finish my carb tune, my needles didn't come with shims. where does a guy source needle shims and theinbetween size main jets some of the Yamaha applications call for. 1m not getting a consistent plug reading all three are mabe too far apart to be able catch it with just shims. may have to rejet some carbs
 
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