SRX with viper crank, clutching and jetting questions

shaggyzr2

shaggyzr2

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Would an srx with a viper crank use the same jetting and clutching as an SRX with the SRX crank? Just wondering because I'm trying to get mine dialed in just right. I've gotten it to perform a quite a bit better now with some jetting and clutching changes but it still could be much better I think.
 
the crank wont make any differance in the jetting, nor will any reeds you add. If the rest is all stock(no porting on cyl or cut heads) and you DONT have the airbox drilled,gutted or cold air kit/modded, stock jetting will be fine
 
Is there any way I can find out if it's had any porting or if the heads have been cut without opening up the motor? I'd like to go with the 01 jetting on it but I don't want to lean it out too much. It was jetted with 47.5 pilots, 151.3, 151.3 and 152.5 mains. with those jets it didn't perform the best so I switched the jetting to 42.5 pilots, 150, 150, and 151.3 mains, that helped but it still isn't quite right. Air box hasn't been gutted and no cold air kit.
 
shaggyzr2 said:
Is there any way I can find out if it's had any porting or if the heads have been cut without opening up the motor? I'd like to go with the 01 jetting on it but I don't want to lean it out too much. It was jetted with 47.5 pilots, 151.3, 151.3 and 152.5 mains. with those jets it didn't perform the best so I switched the jetting to 42.5 pilots, 150, 150, and 151.3 mains, that helped but it still isn't quite right. Air box hasn't been gutted and no cold air kit.
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no way your gonna tell without knowing if works been done or taking it apart and looking/measuring but you can read the plugs and piston wash and simply jet it to what the engines telling you it wants.

the differance you have now in main jets is so small from 150 to 151.3 youd never notice it on a sled, so thats not your issue. Those pilots (42.5) will work even with a trail ported srx,so thats not your issue. so if its not running right theres only 1 other carb circuit left.......

Are the needles set stock?
 
shaggyzr2 said:
Needles are at 3.25 right now.
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seriously doubt you need to have them raised, srx is already richer then a viper is because the needle and nozzle are richer from the factory. needles will make a engine kinda blubbery if too rich so that might be part of your running issue.

The rest of your driveability problem then is likely your clutching set up
 
It doesn't seem to be pulling enough rpms, and feels kinda blubbery when under a load, deep snow or up a steep hill. I had it out last night, engagment is under 4000 and I can barely get it over 8000 rpms.
 
needles will make it a little blubbery if its rich but the clutching maybe is whats wrong, whats in it for clutching now?
 
shaggyzr2 said:
Stock weights, 4.5 both holes, www spring, secondary has 51/45 helix, green spring set at 60.
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if it will barely pull 8000rpm then you have something wrong somewhere in it (power wise)with that set up. Sounds like its not making full engine power or something.

1.)pull the spark plugs and look at them, what color are they?? refer to tech section for plug pics and what to look for.
2.) make sure powervalves are set correctly and have no pull thru's
3.) make sure the sleds gearing is correct, should be like 22/38-23/38
4.) put on a brand new drive belt.
 
Plugs look good, kind of a tan color. I checked the powervalves out a few times now and they look good, not sure on the gearing. You think the stator could be going bad? Weird thing is...about a week ago I threw in a different CDI box and it pulled hard, easily reached peak RPMs, the next day it went back to the way it was.
 
shaggyzr2 said:
Plugs look good, kind of a tan color. I checked the powervalves out a few times now and they look good, not sure on the gearing. You think the stator could be going bad? Weird thing is...about a week ago I threw in a different CDI box and it pulled hard, easily reached peak RPMs, the next day it went back to the way it was.
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1.)has it done anything strange like sound like it fouls a plug for a second then picks back up?
2.)tach erratic at times if you flip the headlight from low beam to high beam?
3.)run better or worse if your in a rough section of trail?

Also add:I would for sure inspect the wiring real well over at the cdi box plugs, they can rub thru there on the footwell, look at the harness real close clear up the side of the steering hoop support. If you dont think you find something there and all of a sudden it runs better again, you have a wiring issue over there and moved or made it have better contact while fiddling around with the harness.
 
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It did foul the center plug the other day then cleared up, I haven't noticed the tach doing anything strange and it doesnt seem to make a difference if I'm on a rough trail. I will have to take a look at the wiring. It looks like someone ran the harnes up around the clutch side of the motor and there is a section that is taped up, I'll peel the tape off and look there and also by the CDI box. This is so damn frustrating!! lol. Thanks for your help
 
Well...I didn't see any rub throughs, tried a different belt, a used one since I don't have a new one on hand that didn't really change anything. I could only get about 90mph out of it, the rpms were just a hair over 8000 and didn't want to climb any higher. It wasn't as bad when I first took it out, but the problem seemed to get worse as it heated up, would get up to around 8000 and then drop to about 7500. Any ideas?? anyone??
 
Thats kinda what I was thinking, I have to pick up a new ohm meter tomorrow so I can test it, I do have another one here so if it's bad I can replace it.
 
One thing I forgot to ad was that my hand and thumb warmers really don't get very warm, the only way to feel heat is to hold your bare hand on them for a while, they feel slightly warm, could that be a symptom of a stator going bad? On my 97sx they get almost too hot when on high.
 
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