Jetting question.

[shonole]

First off, yes I've searched.

Okay, so my bike is running a stage 3 dynojet kit (I know, I know, crap) and a K&N drop in (soon to be replaced by lunchbox).  I decided the other day to place a washer on the needle to help smooth the powerband a bit.  Instead of a washer, I used a nitrile o-ring (I've read before that it was okay).  After installing the o-ring, the bike ran great in the upper RPMs, and seemed to have more power.  However, it was unrideable at lower RPMs (stalled unless you gave it throttle).  After removing the o-rings, it runs okay again.  Any thoughts as to why? 

Also, my bike runs great at anywhere up to half, or even 3/4 throttle.  But at full throttle, it refuses to accelerate.  I can run it at full throttle and the bike will maintain speed, but if I immediately drop it to 3/4 or less, it will accelerate.   

Any thoughts?

Thanks!

[Paulcet]

First off, yes I've searched.

Okay, so my bike is running a stage 3 dynojet kit (I know, I know, crap) and a K&N drop in (soon to be replaced by lunchbox).  I decided the other day to place a washer on the needle to help smooth the powerband a bit.  Instead of a washer, I used a nitrile o-ring (I've read before that it was okay).  After installing the o-ring, the bike ran great in the upper RPMs, and seemed to have more power.  However, it was unrideable at lower RPMs (stalled unless you gave it throttle).  After removing the o-rings, it runs okay again.  Any thoughts as to why? 

The Dynojet needle has a much more aggressive taper, so a little bit of rise on the needle is really a lot of difference.  Hmmm.  Stage 3 with drop-in.... might be just too rich for that.

[shonole]

First off, yes I've searched.

Okay, so my bike is running a stage 3 dynojet kit (I know, I know, crap) and a K&N drop in (soon to be replaced by lunchbox).  I decided the other day to place a washer on the needle to help smooth the powerband a bit.  Instead of a washer, I used a nitrile o-ring (I've read before that it was okay).  After installing the o-ring, the bike ran great in the upper RPMs, and seemed to have more power.  However, it was unrideable at lower RPMs (stalled unless you gave it throttle).  After removing the o-rings, it runs okay again.  Any thoughts as to why? 

The Dynojet needle has a much more aggressive taper, so a little bit of rise on the needle is really a lot of difference.  Hmmm.  Stage 3 with drop-in.... might be just too rich for that.

I was thinking that too.  I'll be getting a lunchbox soon, so that should help, no?

[shonole]

Thinking of pulling the trigger on a lunchbox this week.  Does anyone else think this might solve my issue?

[Kijona]

Thinking of pulling the trigger on a lunchbox this week.  Does anyone else think this might solve my issue?

I think what would solve your issue is returning the carb to stock with a 40 size pilot jet and one single washer on the needle. I'd be curious to see how it runs without the washer first, though.

[shonole]

Thinking of pulling the trigger on a lunchbox this week.  Does anyone else think this might solve my issue?

I think what would solve your issue is returning the carb to stock with a 40 size pilot jet and one single washer on the needle. I'd be curious to see how it runs without the washer first, though.

I've been seriously considering just going back to stock.  But it runs really well, except approaching full throttle.  I've got 40 pilot jets on it now, and it starts easy with mid choke, and I can wean it off after a few seconds. 

I had replacement needles, but somewhere in the process they got misplaced, so I'm stuck with the thin dynojet needles for now.  If it will run well with a lunchbox, I'll just go that route, rather than having to strip the carbs down again.

[Kijona]

Thinking of pulling the trigger on a lunchbox this week.  Does anyone else think this might solve my issue?

I think what would solve your issue is returning the carb to stock with a 40 size pilot jet and one single washer on the needle. I'd be curious to see how it runs without the washer first, though.

I've been seriously considering just going back to stock.  But it runs really well, except approaching full throttle.  I've got 40 pilot jets on it now, and it starts easy with mid choke, and I can wean it off after a few seconds. 

I had replacement needles, but somewhere in the process they got misplaced, so I'm stuck with the thin dynojet needles for now.  If it will run well with a lunchbox, I'll just go that route, rather than having to strip the carbs down again.

Well, is it acting like it's running out of gas or just choking down? A good way to figure out if adding a lunchbox will affect it...if at all...would be just to remove the air filter from the airbox all together and see how it runs. This would simulate drastically reduced intake restriction. That would tell you whether adding a lunchbox would do you any good.

[shonole]

Thinking of pulling the trigger on a lunchbox this week.  Does anyone else think this might solve my issue?

I think what would solve your issue is returning the carb to stock with a 40 size pilot jet and one single washer on the needle. I'd be curious to see how it runs without the washer first, though.

I've been seriously considering just going back to stock.  But it runs really well, except approaching full throttle.  I've got 40 pilot jets on it now, and it starts easy with mid choke, and I can wean it off after a few seconds. 

I had replacement needles, but somewhere in the process they got misplaced, so I'm stuck with the thin dynojet needles for now.  If it will run well with a lunchbox, I'll just go that route, rather than having to strip the carbs down again.

Well, is it acting like it's running out of gas or just choking down? A good way to figure out if adding a lunchbox will affect it...if at all...would be just to remove the air filter from the airbox all together and see how it runs. This would simulate drastically reduced intake restriction. That would tell you whether adding a lunchbox would do you any good.

It's bogging down.  At full throttle it barely holds speed and refuses to accelerate. 

As soon as this rain passes, I'll go ride it without the filter and see what that does.

[Funderb]

he's right, stage three is too much for stock airbox. Get a lunchbox put on there. You're going hyper rich at WOT because of the dynojet needles, and it cant pull the air to compensate.


The nitrile washer you used may have enriched the idle mix too much to idle properly. What do your plugs look like? I'm guessing black or fouled.

do you have a performance exhaust on there? (It wont really change flow drastically, but does lean the mix a tad.)

[shonole]

he's right, stage three is too much for stock airbox. Get a lunchbox put on there. You're going hyper rich at WOT because of the dynojet needles, and it cant pull the air to compensate.


The nitrile washer you used may have enriched the idle mix too much to idle properly. What do your plugs look like? I'm guessing black or fouled.

do you have a performance exhaust on there? (It wont really change flow drastically, but does lean the mix a tad.)

Stock exhaust.

That's the crazy part, the plugs look great.  But then, I don't ride it at WOT because of the aforementioned problem. 

[shonole]

he's right, stage three is too much for stock airbox. Get a lunchbox put on there. You're going hyper rich at WOT because of the dynojet needles, and it cant pull the air to compensate.


The nitrile washer you used may have enriched the idle mix too much to idle properly. What do your plugs look like? I'm guessing black or fouled.

do you have a performance exhaust on there? (It wont really change flow drastically, but does lean the mix a tad.)

Rode it today with no air filter (don't worry, I won't be doing it for long), and it almost completely resolved the issue.  Felt so much better.  I'm certain that with a lunchbox, it will resolve the issue completely.  Thanks everyone!   

[Big Rich]

For future reference, you can cover the air intake port with a layer of filter foam (like from a Shop-Vac) instead of running nothing at all. It will stop some of the big stuff from getting in your carbs, but has practically zero flow resistance. 

[shonole]

For future reference, you can cover the air intake port with a layer of filter foam (like from a Shop-Vac) instead of running nothing at all. It will stop some of the big stuff from getting in your carbs, but has practically zero flow resistance.

You know, I actually considered that.  Wasn't sure how it would do.  Thanks!    I may do it until my lunchbox gets in. 

[Big Rich]

Have you ordered a lunch box yet? And what are your plans for the drop in filter you have now?

[shonole]

Have you ordered a lunch box yet? And what are your plans for the drop in filter you have now?

Ordering it shortly.  And no plans, as of yet.  If you're interested, I can snap some pics for you.

[Big Rich]

I have a used lunchbox that came off my GR. Only on last season (about 2000 miles). If you are interested in a trade, it might work out for both of us.

As long as your drop in isn't thoroughly destroyed, pics really aren't needed.

[shonole]

I have a used lunchbox that came off my GR. Only on last season (about 2000 miles). If you are interested in a trade, it might work out for both of us.

As long as your drop in isn't thoroughly destroyed, pics really aren't needed.

That would be awesome!   

It's in good shape.  Could use a cleaning (but it's not bad).  I already took some pics, so I'll PM them to you anyway.   

[Kijona]

Well, since you're going to all the trouble of messing with the airbox and all that stuff, you might as well put a more free flowing exhaust on there as well. With as rich as it sounds like it's running, you could probably almost go straight pipe on it.

[Big Rich]

Actually, straight pipes reduce power output except for a very narrow range of rpm. That's why they are called  "drag pipes". Here's a good video from S&S Cycles :

http://www.youtube.com/watch?v=KjKUKhHQLHg

Shonole, I didn't get a chance to mail that out today. I'll definitely get it out tomorrow.

[shonole]

Actually, straight pipes reduce power output except for a very narrow range of rpm. That's why they are called  "drag pipes". Here's a good video from S&S Cycles :

http://www.youtube.com/watch?v=KjKUKhHQLHg

Shonole, I didn't get a chance to mail that out today. I'll definitely get it out tomorrow.

No problem.  Neither did I.  Lol.  Definitely tomorrow though.