Dyno Jet SOLUTION!

[mercdude63]

This is good advice for anyone who is looking to put dual pod k&n filters, full V&H exhaust plus a stage III Dynojet kit on their GS.

Follow the directions in the kit. THEN read this.

Ok, so this is what i diagnosed "the problem" (AKA what other DJ kit owners should do) as:

1. The needles are set too rich

2. The pilots are set too lean

As said in the instructions of the DYNOJET kit.

Solution:  One plug in with restitor hole, other solid plug out on each slide. Put the clips on the highest position on the needles and put about 2.5 turns out on the mixture screw. Adjusted idle up to 1200rpm.

SHOULD run like a champ... unless somethings really messed up with my stuff. I MIGHT have a bigger pilot jet installed, but i don't think so. I THINK that the guy before me put a bigger main jet, but i'm not a 100% on that. I will email the guy and find out. If he had put a bigger pilot jet, then that would possibly explain why the bike was bogging when the main jet kicked in. however, even after i got the needles adjusted, there was still a slight hesitation... so i SUSPECTED THE PILOT SYSTEM... like i've been thinking. So i leaned the mixture screw out, got worse. Obviously i richened it, fixed the hesitation about 100%. I MIGHT be able to go a little richer on the mixture, but then again, i might need to get bigger pilots.

Regardless, the bike runs GREAT now. No hesitation, or very very minor (i mean we ARE talking about a 500cc here), on high gear low rpm take off (aka idle-1/4 throttle position). I am about 98% sure this is about as good as it gets.... but i don't do this for a living. I might go to a bigger pilot jet, but seems to be working fine with what i got in it already... so why fix something that isn't broke???


Jon

[JamesG]

You should have been able to read the numbers on the main jets. They should be 122.5 if they are stock.

I suspect that you don't have stock mains because of where you had to clip the needles.

If you do have stock mains, DON'T adjust the needles any because they are already at full lean. Going with bigger mains will make it too rich again.

[brandiwine]

have you not had any problems with the petcock?  i own the same year bike, formerly the same color, and i've had really intermittent fuel issues.  from what i've come up with from help from the forum is i'm going to have to move up to a pingle petcock creating a more direct fuel path to the carbs.  it seem like i'm draining the float bowls with it in the ON position.  Prime position doesn't "really"  fix the problem.  

anyway, i didn't see that mod in your signature list.

[mercdude63]

They are not stock and i think that DJ has their own numbering system for their jets.

This is just advice for Dynotjet stage III jet kit owners who are putting this into their bike in combo with full pipe+pods.

peace!

[The Buddha]

Hey I told you slide not comming up quick enough... I am going to do exactly this to caddmonkeys carbs.
Cool.
Srinath.

[mercdude63]

ha-ha, no you didn't. You said they were coming up too fast. I appreciate the help though...


Maybe I CAN FINALLY CONTRIBUTE to the group with this post.

jon

[The Buddha]

I said one then the other, but you also had 2 restrictors in and then you had the one wiht little hole and the other one removed...
Cool.
Srinath.

[octane]

I've got K&N pods and full V&H exhaust with an ignition advance. Did the stage III DJ kit and the bike ran way too rich.  We put the bike on the dyno to tune it and the solution in my case was to replace the 134 main supplied by DJ with a 124 to lean the mixture back. Also found a bad needle valve in the carb which was replaced. Just those changes smoothed the A/F curve and netted 1.1 peak hp.

http://www.octaneonline.com/GSdyno.htm

[octane]

Oh, and I did drill and plug the slides per DJ's instructions - EXACTLY as they recommend. Clips are at the top of the needle, no more room to adjust!

[mercdude63]

Ok so i THOUGHT i solved this... but i guess not! SHIAT.

So i did a slow engaging of clutch, then full throttle and i got a small bog... which i thought i took care of. I guess i was just rolling on the throttle too slow and worked past the bog. I think what's going on, and i just spoke with DJ about this as well, that the entire mixture is running rich (hence why we have to run the clip as high up as possible).

I called DJ and they said that there's a "Note" on the instructions for this particular bike to adjust the float level if the needle can't clean up power below 4K (right where I have the problem)--looked like a generic tip to me, but OK. This note is through "hours of dyno-tuning and scientific research." Apparently when you do this mod, you must change the float level on the carbs. I guess by adjusting them 1-2mm's it should lean the entire mixture out. I THEN suspect that their initial setting will work perfectly. I'm going to do this this weekend and i'll let you know. My other suspicion was to change the main jet... but if you already did that and it's still running too rich (aka moving the clip to the top of the needle), then i suspect that the float level is F'ing everything up.

[SPARKPLUG1977]

NEVER LIKED DYNOJET KITS.  FACTORY JET KITS HAVE REAL NUMBERS ON REAL MIKUNI PARTS AND THEY DONT ASK YOU TO DRILL OUT YOURR CARB PARTS. BUT I'M NOT CERTAIN FACTORY EVEN MAKES A GS JET KIT.

[SPARKPLUG1977]

JUST CHECKED... THEY DO HAVE THEM

[The Buddha]

Yup... Factory = DIY with stock ... just stock needles with extra grooves in them and mikuni jets... The whole idea behind DJ is that they started out by making a ket kit that will let you jet it wihtout taking off the carbs... but the caps on mix screw pretty much screwed that deal...
Cool.
Srinath.

[mercdude63]

:lol: yeah i guess that would mess up the situation. I'm just dumbfounded with this... this is my first real experience with motorcycle carbs and jetting... i'm just so glad that i don't have a I-4 to be doing this to 4 carbs! Although, my father did a DJ kit on our cbr600... said all he had to do was drop the clips a few positions and it worked fine. What i'm thinking is that the V&H exhaust really doesn't flow that great as compared to the other newer exhausts and that's limiting us. I put a race baffled V&H slip on the cbr with drop in k&n and thats' all my father had to deal with. CHHEEEZZZZ much harder when you're working the crap out of a little 448cc motor to get 45-50rrwhp.

Oh speaking of which, i rode a sv650 and i was impressed with the power difference, but it was the power delivery that really was different. I didn't like it at all... our gs=small i-4 and a much more linear power curve in my mind. I didn't like how all you had to was get a little into the throttle and you're in the power band already... i like knowing what's ahead of me in the power curve. Maybe i should just post this in another topic.