98 vmax 700sx studders at WOT

HD RACING

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98 vmax 700sx studders at WOT NEW INFO ADDED

We were riding yesterday in open fields and I noticed that at WOT the sled has a hesitation and feels like the engine cuts off momentarily at WOT. We also had a problem with the TORS and I bypassed it. I believe the TORS is from my 2" riser block I just installed but I will confirm tonight once the garage heats up. I will also be taking the carbs off to give them a thorough cleaning and put the recommended 142.5 mains in. Are there any known problems or probable causes of this studder? All three pugs are caramel brown and compression is within a few pts across all three cylinder. Brand new tank of gas and Klotz oil.

Thanks for the help guys.
 
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Its just snow dust getting in ..I have the same problem when im riding fast in wide open fields!
 
New info

All three reed cages and petals are in as new condition. The boots are pliable and have no cracks. The carbs were not dirty and have the stock jetting. the screws were set to 2 turns and I believe stock is 1 1/2. Should I put this to the stock 1 1/2 turns out setting? Compression was 150 across all three cylinders with the reed cages and carbs off.

The TORS sensor at the carb reads 5.6 ohms when the throttle is closed and open when the throttle is opened and the wires going to the thumb throttle read continuity when the throttle pivot is pushed towards the center of the handlebars so I believe that is OK. I think I need to adjust the end play after adding my riser last weekend at it will solve the problem with the TORS.

I found something while I had it in the garage tonight that I think may be causing my problem. The track is hanging very low, 3.5" low. I put adjustable transfer rods on the machine and did the tighten up your skid stuff and had not adjusted the track after riding the machine. Can this cause the drivers to miss a window and over rev and hit a rev limiter because that is what it sounds like? I have a tiny tach for my race boats and I will put it on this machine to record my max RPMs and report back.


Anyone have any ideas after this new information has been added?
 
ignition wires and cap ohm's value

Does anyone know what the acceptable values are for each plug wire and cap?
 
5,000 Ohms, I wasn't aware of any rev limiter on the SX700, either that or never reached it. I have 4 of these sleds and they are read about 115 psi, compression, might be my gauge or yours. If it is snow injection there were some covers that you could get to filter out the snow on the filter under the dash. You may have an issue with either the coils or the stator. The service manual has tests for the coils as well as the stator.
 
150 psi comp sounds a bit high for a stocker, maybe the carbs and reed cages being off fudged the #'s a bit. I know my 97 had 130psi all 3 with 11000 on it, all stock.

On your engine missing, could it be a fuel delivery problem? Fuel pump weak, not keeping up at WOT?

Are the plugs caramel brown when this is happening, or after the fact when you check them?

Just a thought.
 
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Plugs are caramel brown. The compression check last week with carbs on was 144 IIRC.

What is the test procedure for the stator and coils?

I have a FP gauge on my race car but no means to check the Vmax any ideas how to rule out the fuel system?

I bought a set of the NGK BR9EIX's just in case one of the plugs was the problem.

Will the 142.5 mains and setting the needles to the stock 1 1/2 turns be safe?

Thanks for the help guys and I will report back if I find anything.
 


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