Hey all members, I'm starting this thread to get an overall view from everyone. I also have a thread particularly in the 900rr section about this matter. For the older carb. model bikes, I'm think about getting a full exhaust system. Is it mandatory to have the carbs re-jetted or can I get away with a K&N filter only. Is it okay to ride....

Please advise the good & bad....if I were to ride it without re-jetting the carb on a full system. Does it damage the bike in any way? I guess running lean.

is this a myth or reality.

 

re-jet is pretty important with a filter AND full exhaust. if it was just a can, or just a filter - id say you'd be fine. remember that re-jetting is more than just screwing some new jets in. needle height, and pilot (mixture) screw are also important tuning. if you're getting serious about your 900rr, i think you should jet it. and with a full system, you're not getting the benefits of it if you don't jet it. all you'd get is less weight and more sound.




oh, and to your myth or fact question. yes, it can damage your motor over a longer period of time. for example, if you rode your bike around town for a week (easy riding) with the full system before you got your bike jetted- there'd be no problems. if you beat the hell out of your bike for a few years - you would probably develop problems. the leaner you run, your motor will run hotter. the little bit richer fuel mixture helps cool the motor somewhat. plus you run the risk of pre-detonation if you run too lean which can lead to engine woes as well

 

^ I agree w/ Conrice.

I doubt there'd be "damage" but the bike wouldn't perform to its potential. If you're going for engine/performance upgrades, follow thru w/ the jetting.

 

Sounds easy enough to take it one step at a time. I can install the full system first, buy the jet kit, see if I can get my local mechanic do it for me....once I get a hold of a full exhaust system, I'll post it up....then get your suggestions on what type of jet kit to buy. So if I get a Vance & Hines full system, I guess I likely need a Vance & Hines jet kit, right?

 

Well, sure! ...If you put it that way. ;-)

 

Nah, you don't have to get any particular brand of kit. I've used DynoJet before, they are pretty good. Decent instructions and lots of different jet size options to allow me to tune easily.

Its a job you should be able to do on your own, the tuning isn't really that hard. Read up on how carbs work so if you do it yourself, you will be able to make sence of the adjustments your making. Having a mech do it is fine, but it will be alot more rewarding if you figure it out by yourself, plus alot cheaper

 

jet numbers are jet numbers. the dynojet kit will give you all kinds of jets. ones for no mods, slight mods, heavy mods, etc. i'm not sure with the 900rr, but usually for the cbrs, it's just a primary jet kit. then they give you an adjustable needle. then they also usually sell you a drill bit to drill through the caps on the pilot screws.

if you found out which jet was recommended for your set up (900rr/full system/air filter), you could just buy those jets.. then you could shim the air needles with special machined washers (people do that quite often on cafe's), and if you have your own drill bit, you could easily drill through the caps yourself. i'm sure you could do it for a just a few dollars if you did it this way. a shop will probably charge you around $300 to jet your bike. or at least, that's what i was quoted for my f3. that's when i said f it, and started really doing everything myself. it's pretty easy and straightforward.

a dynojet kit comes with a write up. and i'm sure there are write-ups all over the net specific for your bike. also, carbs tend to work the same way, so if you find a really good write-up for a different bike, there's still a good chance it's close to what you would do.

 

thank you conrice.. you saved me some reading tonight...we were discussing this in the 900' s thread and I basically replied the same way except without the through walk- through.. mine explanation wasnt as informative..
anyway bottom line is you always want to do it right and protect our machines...

hey estate: I hope you didn't think I was full of it this morning!!! I'll tell you, a good book to buy is a Haynes manual... it's about the third the size of the other one everyone likes to buy.. the reason I mention it is: it's a really quick read with everything in there covering all the tune- up stuff and all through that book is all the does and donts including what we' 're talking about.. anyway great resource for 20 bucks off Amazon.. anyway you did a good thing posting your question in the general.. I reguard all the guys who answered this thread "the Honda elite" hope you enjoyed that guys.. I really do..

p.s. fact: in the manual it pretty much explains it the way conrice did!! and over time , a good amount of time, you will damage the motor!!
a+ and +1 conrice for knowing that off the top of your head..
jay

 

Here's my 3 goal from now till March 2013....

1. Drop pan - change my car's transmission oil.

2. Shop and purchase a full system exhaust.

3. Get my carbs jetted & clean at the same time....

4. Replace my chain & sprocket...

Oops...I thought only 3...LOL well #2 & #3 can be one job...

Thanks everyone, I'll keep you guy posted...

 

definitely re-jet it. i got a full two bros system on my f3 and it just ran like crap, i actually just got the carbs out yesterday and installed a dynojet kit. its a real simple installation and you get step by step instructions, as well as trouble shooting instructions that will help you figure out any tuning issues.