New to me GS850 jetting questions

[boingk]

I got my jets over the net for $3 a pop with $3 postage, very reasonable. I did get two sets in different sizes though, so it ended up costing $35 all up. If you can't find them locally try the internet - I used the jets from this guy on ebay:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=350155392463&viewitem=&_trkparms=tab%3DWatching

Cheers - boingk

[qwqb]

You dont need that kit.

I orderd that kit to rebuild my carbs because the bike has not been running for a while and at least one of the carbs leaks gas when I try to start it. Along with cleaning and rebuilding I want to rejet because I see that as being a potential problem.

[67fire]

As practically no one seems to post their location...
Has anyone thought to allow for altitude with these jetting recommendations?

Just sayin'

Eric

[boingk]

Good observation. Not much altitude here so we don't generally think of it as an issue.

I'm at 2,000ft.

By the by, nothing wrong with a rebuild if you think you need it, and leaking gas is a sign of at least one (if not several) things wrong.

- boingk

[Steve]

It has been my opinion (however mis-informed that might be) that jetting for an altitude is only practical if you will never go below that altitude. The mixture will richen up as you go up in altitude and, yes, that will reduce power a bit, but most of the power reduction is from the overall lack of oxygen, not so much the rich mixture. Conversely, as you go down in altitude, your mixture will lean out. If you had set it correctly for Denver at 5,000 feet, you will be close to dangerously lean as you go away from there on a long trip. Granted, it's likely only one or two jet sizes, but it can still make a difference. Better to keep your mixture a bit rich and be safe. On the other hand, if you live in Leadville, Colorado (just over 10,000 feet) and don't ever plan on taking your bike down to Denver (100 miles away) or Colorado Springs (6000 feet elevation and 105 miles away), go ahead and re-jet.

Racers will change jetting from hour to hour, sometimes, to keep peak performance based on altitude, temperature, humidity and barometric pressure. They can get away with all those changes because the amount of time they will be using that jetting combination is rather limited and very specific to those conditions. The rest of us should just settle for a compromise that works pretty well most of the time.

Or you can go with fuel injection. It compensates for altitude as well as temperature.

.

[tejasmud]

I got my jets over the net for $3 a pop with $3 postage, very reasonable. I did get two sets in different sizes though, so it ended up costing $35 all up. If you can't find them locally try the internet - I used the jets from this guy on ebay:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=350155392463&viewitem=&_trkparms=tab%3DWatching

Cheers - boingk

Dang that is high, but not as high as I have seen before. Some places want $6-$7 each.

I do all my shopping for jets at Z1 Enterprises. If located outside of the US, not sure the cost on shipping though.

http://www.z1enterprises.com/SearchR...eyWords=Mikuni check Page 3.

[Guest]

I orderd that kit to rebuild my carbs because the bike has not been running for a while and at least one of the carbs leaks gas when I try to start it. Along with cleaning and rebuilding I want to rejet because I see that as being a potential problem.

Not trying to be an A-hole but if you already bought the kit why did you ask?
I dont know first hand but most here will tell you those jets in that kit are junk. I asked before I bought em.

Bout the only thing in that kit worth using are the 7 dollar bowl gaskets.

[boingk]

Damn, $1.60 a jet? Nice. As for $6~7 each, thats what I was basing my buy being alright on, after having been quoted something ridiculous like that from a place a state away. Nowhere local carries jets much anymore...

- boingk

[qwqb]

Well thats alright if the jets in that kit are junk, as it seems like I will have to buy bigger than stock jets anyways. I pretty much just bought the kit in order to rebuild the carbs and get some new pieces in there, as I know the carbs have some major problems. As far as jet size, clearly there is no one distinct answer as for what is right to run. Do you guys just guess and check, and then buy again? Or whats the best route so as to not spend a ton of money during trial and error?

[boingk]

Guess and check is mostly it. Figure one size up for a decent pipe and another two for running pods, seems to be the rule of thumb. I ordered 2 and 3 sizes up, and used the lower size first. Wasn't right, so went the higher ones - they see ok.

Trial and error. You'll get real good at chinging jets haha.

Cheers - boingk

[doctorgonzo]

MIne has 165 mains in it, lol.

DJ 165 mains that is..

Yeah mine is a 1000, but running 170 DJ mains, so about a 160 Mikuni.

[qwqb]

So before I make any more stupid purchases haha, this is a good choice as far as jets go? http://www.z1enterprises.com/detail.aspx?ID=63

[67fire]

So before I make any more stupid purchases haha, this is a good choice as far as jets go? http://www.z1enterprises.com/detail.aspx?ID=63

Heck ya! And at half the price of your local dealership, order a few sets.

Eric