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First off to those reading this that are willing to help me, thank you. I know this is long so I apologize but I like to include as much info as possible. I bought an 02 Sportsman 700 a few months back and have had no time to work on it. I know that one fix for poor running machines is a new ignition system but I want to find out if I can get this thing running good without the $500 upgrade so I'm in the process of rebuilding the carb and have a few questions. I live in VA and will probably mostly ride in this area, up in WV and possibly up in MI (0 - 3000 ft)
1) What MAIN JET should I rebuild with?
The service manual says for the MAIN JET:
0-6000 ft & above 40*F 162.5
0-6000 ft & below 40*F 167.5
The service manual also states that a 162.5 was installed stock from the factory
However, on the Polaris website if you go to order parts they note that the jet they're selling is a 152.5 or 155 and I bought an aftermarket carb rebuild kit and it included a 157.5.
There was a 162.5 in it when I disassembled it for cleaning
So should I go with the 157.5 or the 162.5??
2) What size PILOT JET should I rebuild with?
The service manual says for the PILOT JET that a 45 was installed stock from the factory which also aligns with what they're selling on the Polaris website and that's what was in the carb when I tore it apart. In the aftermarket carb rebuild kit, it included a 47.5.
Is there any reason to even consider the 47.5 or just use the 45 and be on my merry way?
Finally, the last question: 3) What height should I set the float at?
In the service manual it notes in the "Float Height Adjustment" section that the float height should be set between 13 and 14 mm, however earlier in the service manual it notes that it was set at the factory at 14.7 mm +/- 1 mm so I’m not sure what to set it at. I feel like on the 99 Sportsman 500 I had previously owned that the "proper" adjustment was for the flat part on the float to be parallel with the float bowl surface but that was a few years back.
Yes the online sites and even Polaris Parts http://parts.polarisind.com/Browse/Browse.asp show a 155 main jet,45 pilot. I'd use the 157.5 and 45 pilot. Also in your manual in the carb section on this BST34 carb there is a jetting chart for altitude and temperature that can help you also. Here's a pdf section on all the carbs Polaris used,parts breakdown,plus float height adjustment( BST 34 13.0mm (.51) +/- 1mm) that should already be in your service manual. On that I'd stay at 13.0 mm on the float setting. https://www.google.com/url?sa=t&rct=...U2gGlaHJWSIlbA If you need additional jets or parts,Jetsrus has oem Mikuni and cheaper generic jets.https://jetsrus.com/a_jet_kit_atv/po..._2002-2006.htm This should help you on the carb but if you're having problems with that Ducati ignition system I doubt if having the carb clean and correct will solve that. Hope I'm wrong.
Thanks for the info and additional links OPT. I was hoping you'd jump in here and try and help me out. Like you - I'm hoping that its not the ignition system. There was a badly burned connection going to the voltage regulator, the carb boot/intake manifold had a bad crack in it, and the needle seat was oblonged on 2 sides so I've still got my fingers crossed.
Here are the picture from the service manual I've got, hence the reason for the questions, especially related to the MAIN JET size and the float height.
I'd still set the float height at 13mm and use the 157.5 main jet. IF it runs better(or worse), you can always plug chop and see what the plugs look like.Should be a tan to medium brown color on the plug.We're about the same elevation,you may have colder temps at times. Still if the Ducati system is acting up,you may not be able to tell good enough on the jetting. Most machines when the ignition was starting to go out ran rich,fouled plugs,popped back through the carb or exhaust. Some people would kill them and came back later and they wouldn't even start. The size increments between the 157.5 to the 162.5 isn't that large to be honest with you. Not really enough to cuss a cat over as the old saying goes.. Plus on the 2003 model 700 they used a 155 main jet. I really think Polaris was experimenting a bit. Here's the 2003 700 pdf manual if you want to take a look.https://www.tradebit.com/usr/valuabl...600700free.pdf
OPT you’re starting to lower my hope lol.... on a maybe unrelated note. I’ve read some posts online talking about some change that was made to these units that required drilling a jet out and a supposed Technical Service Bulletin. The only thing I can think was that they were having to drill out the plug for the Pilot Air Screw. Do you recall anything related to that by chance?
Also is there any way to look up all of the Tech Service Bulletins related to a particular model by chance?
Way too long ago for me to remember any tsb or in house tech bulletin on this,but I think you're taking about removing the block off plug cover the fuel mixture screw. I've had to do that on a lot of carbs,not especially on the 700 but appears that if the manuals are right,1.5 turns out is on the lean side. IF you want to do it,here's a good video on this,but always turn the screw in and count the number of turns out from the factory. The guy in the video just screwed that part up.
You don't have to remove the screw,but IF you get it running decent this screw fine tunes the idle mixture. Engine has to be warm. Most carbs starting point was 2 turns out,then adjust in or out slowly until you have the best idle.Best to have small hands and small screw driver to get to it or a carb tool made for this. You can go cheap or expensive on these.
I didn’t know if anything model specific stuck with you or not. Is there anyway to find any TSBs related to a specific model?
I assume the same as you that it was probably that plug and I’m wondering if it wasn’t to get it turned out a little bit more from the factory setting of 1.5. I’ve also read that other people say to set it out 2-2.5 turns. I’ve set mine at like 2–1/8 I think but will double check. I remove and clean EVERYTHING when I do a rebuild so I know to just snug and then back out but thanks for also letting me know in case I didn’t.
I’m hoping to be able to report back by this weekend but looks like a busy week... if I only had a heated garage or shop to work in.
Does take a little for the old brain to heat up and remember some things from almost 16 years ago plus with the assistance of older posts.One tsb was for the crank case vent line freezing up,another was for a metal brace over the plastic water pump cover to keep it from warping. Later models went to a metal cover
"This was a Tech Service Bulletin for models in '02 and some early '03's."
The crank breather filter should be omitted for colder climates, this was also a Tech Service Bulletin (TSB). It added an insulated hose (w/1" slot).
The TSB is #S-03-05 and the part # is 2202744
Also some machines, mostly '03's have cold weather start jetting updates, both of the TSB's and the jetting should have been taken care of under warranty."
The last one especially applied for use in colder climates such as what you have. On a tsb like this one down here, we generally didn't bother with them as it didn't apply to our area. That's why I couldn't remember anything on carb updates..Plus according to the post the carbs affected were listed as 2003 models,not the 2002 that you have.
Well I got the carb rebuilt completely a week or so ago and everything back together today after putting in some new spark plugs and it won’t start. It sounded like it wanted to start a few times but didn’t.... so I will start by checking my fuel delivery and spark and go from there. I’ll update as I continue along...
01-06-2018, 07:49 PM
02 Sportsman 700 Carb Questions - Jets & Float Height
