2012 carb cleaning and viper needle settings

rx1jim said:
Mr. Viper,

What brand octane booster do you reccommend? Thanks,

Jim


Jim, I just use the 104 brand in the black bottle at most auto parts stores. its like $6-7 a bottle. I dont measure.. just dump roughly a half bottle in to a full tank, so you get 2 full tanks to 1 bottle of booster.
I know it doesnt make 87 into 93 or anything close, but with the raised needles and booster, I have not had a single failure yet. So its cheap insurance........ as 1 piston is a $100! :o| :o|
 

Hello Don,

I agree completely with you about using octane booster as low cost insurance. Vipers, SRXs and other high performance 2 strokes of 10-15 years ago were developed with gas which had significantly different characteristics, the same problem as trying to run muscles cars of the 60's and 70's on today's gas. Back then we had terrific gas like Sunoco 260. The challenge with gas will only get greater. I am thinking of putting the heads from a 98 or 99 SRX on both of my SRX engines to lower the compression to make them a little more tolerant of lower octane gas. I've begun to stock up on octane booster for this season. My one and only meltdown event cost me over $600 in parts: piston, rings, crank rebuild, head, replated cylinder, gaskets and seals, etc.. I'll keep riding my SRXs for local trips in my favorite riding region where I know I can get 91 or 93 octane gas but for saddlebag trips I ride my RX1.
 
Im doing this tonight to my (stock) viper. Any idea where my air screws should be? As long as im taking the carbs out, I'd like to check them too.
Thanks, Jason
Also, i bought the cheap methol alcohol (i think) octane booster. Is that the right stuff to run? It was $1 / bottle at fleet farm so i bought 12. :)
 
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All I can say is WOW !!!!...Had first opportunity to really run SLP Triple piped sled on the trail and WOW what an improvement over stock. Fit and finish of SLP set-up was near perfect. Raised needles, re-jet for elevation, increased pilot jet size 5 points, and installed tourque limiter. Sled runs HARD...This is the mountain version with a 144" track and I still managed an honest 100 mph on a long pull, verified with gps. Faster now then my stock SRX700 was !!!

I also ran the sled for extended period in the "lean" zone, doing 20-30 mph, like my girls will ride it and my digital Koso gauge never went above 168 f.

Should be very reliable performance mod. That Yamaha triple motor RULES !!!!
 
So my needles are at 3.25, and my idle screws are at 2 turns.
Last weekend I was riding with my wife on the back so I was taking it easy going about 25-35 around a lake. We were just crusing looking at house and cabins taking a nice cruise. Got about 10 minutes in and engine started cutting out. Limped it back to the bar and it died. Checked the plugs and all looked normal (not wet). I at first thougt I fouled a plug. Then when they came up dry, it went on the trailer. Have not had time to look into it further. My question is, since I adjusted the carbs, do I need to be more aware of driving in the mid ranges now? Should i have been more on and off the gas during that ride? Is it more prone to foul plugs now?
Thanks in advance,
Jason
 
JDViper said:
So my needles are at 3.25, and my idle screws are at 2 turns.
Last weekend I was riding with my wife on the back so I was taking it easy going about 25-35 around a lake. We were just crusing looking at house and cabins taking a nice cruise. Got about 10 minutes in and engine started cutting out. Limped it back to the bar and it died. Checked the plugs and all looked normal (not wet). I at first thougt I fouled a plug. Then when they came up dry, it went on the trailer. Have not had time to look into it further. My question is, since I adjusted the carbs, do I need to be more aware of driving in the mid ranges now? Should i have been more on and off the gas during that ride? Is it more prone to foul plugs now?
Thanks in advance,
Jason

no, you have something else going on its not the needle adjustment
 
Sorry to hijack this thread, but I am checking out my needle clip settings for the first time on this motor. 98 SRX 700 and I only have 1 plastic washer for each needle?? Needle is in the 3rd slot down with the 1 washer underneath. I want to richen it up, so should I just keep 1 washer under and put it in the 4th slot?
....also, can I still remove the middle carb set screw in the rail? Even though there's not an adjuster like the PTO and MAG carbs?

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I only have 1 plastic washer for each needle??

Check to be sure there wasnt one above ( the one you see ) and one below the washer. It may be stuck to the carb and not come out when you pull the needle. Be careful to not loose it in there if it is present. Sometimes they stick to the needle and some times they stick to the carb....
 
Definitely only 1 washer....

Edit: I'm an idiot..... 2 washers. So 4th spot, 1 up, 1 down is better than 3rd spot, 2 under?

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this needle raising is for the vipers as they are set up leaner from the factory with differnt needles and nozzles in the carbs. The srx doesnt have too many issues as far as needle settings as its richer from the get go.

the stock setting of the needles for a srx700 is the 3rd groove down from the short end of the needle, with both shims under the clip.
 
Definitely only 1 washer....

Edit: I'm an idiot..... 2 washers. So 4th spot, 1 up, 1 down is better than 3rd spot, 2 under?

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Yes, You're at 3.25 with 4th groove, one clip up and one down. Little richer.
 
Not trying to hijack this thread, but can I run 2,5 setting on my 97 Venture 500 liquid? I am at 330-1600 feet, run regular fuel and the coldest I ride in with that sled is -18c (0F). It seems rich now.
 
In my manual it does mot give me 1/4 setting but only half setting, so going for thr stock setting 3 to 3.25 will be sufficient?? Looking to do this, 3.25 is clip in 4 groove, both washers on top correct?
 
I don't think there is such thing as a 1/4 adjustment.

sure there is, how about measuring where the needle sits with the clip in the 4 th groove and both shims on top, see if its richer then 3.0 and then leaner then 3.50, let me know.....
 
This needle position may be part of the reason my center cylinder overheated on my Viper this season. I got a new sled couple of years ago ( MXZ 600 etech, I know I know sacrilege ) and my wife was on the Viper couple of weeks ago. I haven't really had a chance to take the Viper out much scince I rebuilt it 2 years ago due to crank issues and poor weather. The conditions were kind of mild and hard packed snow, so not the greatest cooling. The wife would have been riding in the bottom half of the throttle range. The temp light kept coming on so we just kept putting snow on the running boards. After about 65 Km the center cylinder heated and nicely squeezed the piston. We were able to make it out of the bush to a restaurant, where she waited 3 hours until I went back to the truck and came back to load up the sick Viper. (No shops around but she managed to spend money at the LCBO, she has her black belt in shopping ). Mr. Viper I have taken your advice and moved the needles up to 4th possition, one washer up and one washer down, I think that's 3.5. I'm waiting for a water pump cover gasket from the stealers but I'll let you guys know how the first ride goes.

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This needle position may be part of the reason my center cylinder overheated on my Viper this season. I got a new sled couple of years ago ( MXZ 600 etech, I know I know sacrilege ) and my wife was on the Viper couple of weeks ago. I haven't really had a chance to take the Viper out much scince I rebuilt it 2 years ago due to crank issues and poor weather. The conditions were kind of mild and hard packed snow, so not the greatest cooling. The wife would have been riding in the bottom half of the throttle range. The temp light kept coming on so we just kept putting snow on the running boards. After about 65 Km the center cylinder heated and nicely squeezed the piston. We were able to make it out of the bush to a restaurant, where she waited 3 hours until I went back to the truck and came back to load up the sick Viper. (No shops around but she managed to spend money at the LCBO, she has her black belt in shopping ). Mr. Viper I have taken your advice and moved the needles up to 4th possition, one washer up and one washer down, I think that's 3.5. I'm waiting for a water pump cover gasket from the stealers but I'll let you guys know how the first ride goes.

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yep sounds like the typical mid range detonation fest. You also can just change the needle settings to the center and mag cylinders if you exhibit any kind of burble. The burble usually is only on very warm days and from what I call putt putt riders. I don't mean to insult anybody its just a term I use to describe non aggressive riders like wifes and older people, or younger kids.

The center and mag cylinders are where 95+% of all vipers will burn down, its the higher compression in those 2 cylinders along with mono head which keeps mag cylinder warmer and then the added ign timing of the viper cdi box. the pto cylinder never blows up, its got lower compression and doesn't build up the heat like the other 2 do so easily.

(((the other possible 5 % burn up the pto cylinder due to dirty carbs... only reason I have EVER seen a pto go down in a viper!! same old problem clogged pilot jets!!!)) almost always first ride of the year too...lol
 
sure there is, how about measuring where the needle sits with the clip in the 4 th groove and both shims on top, see if its richer then 3.0 and then leaner then 3.50, let me know.....


Never new that Mr.viper! Thanks. Always thought the 3.5 was a bit rich for my liking. On a stock viper it burbled a bit to much for me cruising around the mid range part.
 


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