rejetting question

i have an 02 sv650s, bmc filter (205/10?), and a full yoshi exhaust system. (installed by the previous owner, i dotn know if he re-jetted after installation)
the mechanic says i should re-jet my bike, but wants 300$ that i dont have .

is there a easy indicator of whether i need to a re-jet or not?
edit: i've read that when the exhaust is cold, and there is black residue on the inside tip of the exhaust can (which there is), it usually means that its running rich
what are the harms of not re-jetting?
if i were to buy the kit, would this be it?
http://cgi.ebay.com/ebaymotors/New-D...spagenameZWD1V
edit: and 300$, alittle costly?

thanks in advance

have you done the tank lift yet, this would allow more air to the carbs.
this makes a differance on it's own.

i'm sure rejetting would not be necessary, unless you want preformace.

There is always a bit of black dirt on the exit of the exhaust....right? I've always noticed it. Otherwise my bike is running rich. Which wouldnt suprise me, the air filter has never been changed to my knowledge at least, not during my ownership

Originally Posted by Airwolf

have you done the tank lift yet, this would allow more air to the carbs.
this makes a differance on it's own.

i'm sure rejetting would not be necessary, unless you want preformace.

im not sure what the previous owner did to the bike, but...

there are two, what looks like, really thick washers that do prop up the tank by like an inch or so.

like i said, i have no idea whether i need it or not (but i do know its recommended after airfilter/full exhaust, but i dont know if the previous owner did or not)

performance isn't that big of a deal. to me, theres no difference between really fast and really really fast.

one the the best ways to know how your engine is running is to check the plugs. do you have a work shop manual. has good pics to show you how they look rich/poor/ good.

Originally Posted by catchsomesv650

i have an 02 sv650s, bmc filter (205/10?), and a full yoshi exhaust system. (installed by the previous owner, i dotn know if he re-jetted after installation)
the mechanic says i should re-jet my bike, but wants 300$ that i dont have .

is there a easy indicator of whether i need to a re-jet or not?
edit: i've read that when the exhaust is cold, and there is black residue on the inside tip of the exhaust can (which there is), it usually means that its running rich
what are the harms of not re-jetting?
if i were to buy the kit, would this be it?
http://cgi.ebay.com/ebaymotors/New-D...spagenameZWD1V
edit: and 300$, alittle costly?

thanks in advance

if you have a full system and a bmc filter, i would imagine that you need to rejet (if its not already been done)...which filter is it? i know you say 205/10 but there are 2 or 3 bmc types with this code, the BMC road, the BMC Race, and the BMC Race RS.........

how does the bike feel? I would say that if you can ride it, then its already been rejetted - maybe not perfectly, but from experience, when i put my BMC Race RS into my curvy (with standard system with a slipon can) it wouldnt even rev above 4k before i rejetted........

by the sounds of it the tank has already been raised (doesnt make a great difference TBH), as said you can tell if your running rich or lean by looking at the spark plugs.......

if i were you i would buy mikuni jets....not dynojet kits as they are so cheap (they are what i used and i think(?) the carbs on curvys are also mikuni, i may be wrong tho).

standard jets are 37.5 (mikuni sizes, not dynojet sizes, mikuni are the standard ones also) with my slip on and RS filter I found that 155 mikunis was perfect.....as you have a full system yours may need to be bigger (depending on which BMC filter you have)....

have you thought about taking the carbs out and having a look at the jets? you will know exactly whats in there then......

$300 u in the states? is that about £150?

thats well expensive to rejet, a qualified / experienced mechanic could easily do it in an hour.....however if he is talking about running it on the dyno etc and setting it up perfect that that could be where the cost comes into it,....

[northwind]

As Dappa D says, there's more than one BMC filter and they're all 205/10 It seems to be a fitment number rather than a part number. But I think you can rule out the Race RS and the Road, if it was an RS the bike'd misfire all over the shop as soon as you got to the mains circuit, and be basically unrideable, and I doubt anyone would go to the trouble of fitting tank spacers if they had a Road.

So, let's assume it's the Race. Which is a decent enough filter, but not a particularily free one, so by itself you wouldn't automatically have to rejet. And the Yoshi, well, not the best system ever (though it's OK- Yoshi annoy me, clearly they can make a great system if they choose, which shows that for the SV they just chose not to) so you might be able to get by without rejetting. But with both, it's going to be a good idea, since otherwise you'll be fairly lean.

So, let's work from the assumption that it's not been done. It'd make sense to fire it on a dyno tbh, take the guesswork out of the equation. $300 for a full rejet is not too awful but for a fuel run alone, it should be much less and that'll tell you for a fact if it needs fixed.

But failing that- the SV has a brilliant lean symptom. Basically, stick it in third, cruise at 5000, 6000 and 7000rpm respectively, then bang the throttle open fast. If it stumbles/stutters before it picks up, chances are it's fairly lean. If it just goes, it's about right. If it "sandbags", ie nothing happens then it slowly picks up, then chances are it's rich. These are all obviously rules of thumb but they can be very helpful.

thank you all for your help, i'll ask around a couple friends to see where they get their re-jetting done and go from there...

Originally Posted by northwind

But failing that- the SV has a brilliant lean symptom. Basically, stick it in third, cruise at 5000, 6000 and 7000rpm respectively, then bang the throttle open fast. If it stumbles/stutters before it picks up, chances are it's fairly lean. If it just goes, it's about right. If it "sandbags", ie nothing happens then it slowly picks up, then chances are it's rich. These are all obviously rules of thumb but they can be very helpful.

when you say picks up, do you mean in terms of rpm or speed?

[yorkie_chris]

When riding normally rpm and speed are kinda related
The shove of power should be instant.

Basically does it run like a bag of w4nk or not? If it runs alright chances are it's already been done.

Post a pic of the top of the filter you have in there.