Author Topic: Jetting!!! Again and again and again!  (Read 288407 times)

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Offline gowen

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Re: Jetting!!! Again and again and again!
« Reply #90 on: May 20, 2004, 05:19:20 PM »
Kawdude, I did decide to take the bike for a run after work today, (well yesterday now) and I noticed it sounded diffrent, more popping and just smoother revving. So, I decided to take it for a few runs slowly and no it still won't idle and no it still smokes, but it has cleaned the rev about 90% down low. I believe the stator has fixed the biggest problem I've been having, no responce! But, I believe I'm still rich down low and in the mid. I am going to try to drop the needle (raise the clip) and try playing with the air screw. BTW, I tried a 165 main and it is great. I'm not used to all the wheelies now. :-)

Anyway, I'll keep posted on cleaning the low up. I am still on a 52 pilot. Running center clip and a 165 on the main. I will check the air screw next. I'm still hoping to find an idle.

Thanks guys! I believe I've gotten the biggest problem fixed!

kawdude

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Re: Jetting!!! Again and again and again!
« Reply #91 on: May 21, 2004, 06:27:08 AM »
So what did dropping to the 165 do for performance?  Is it cleaner?  I'm at a 170 and it seems fine but rich.

Offline gowen

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Re: Jetting!!! Again and again and again!
« Reply #92 on: May 21, 2004, 11:34:08 PM »
So far, dropping to a 165, I have not felt much improvement in power, maybe a slight bit, it does feel cleaner and less smoking up top.

Twist-a-grip

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Re: Jetting!!! Again and again and again!
« Reply #93 on: May 24, 2004, 01:48:16 PM »
Just to let you and Kawdude know, I too have experienced the lack of idle with my bike.  Jetting is clean from bottom to top.  No appreciable wear noted on idle screw or slide bottom, float and choke circiut OK. Idle srew turned all the way in and not quite enough for a good idle. The difference between mine and yours is my idle srew uses a lock nut instead of a spring.  Well, as picky as I am I could'nt leave it that way.  I went and purchased a 5mm X .80 X 40MM bolt that just happened to be the right size. I then ground the tip down to match the stock unit and I now have a good idle with a good amount of adjustment.  If you try this please verify that you do indeed have the same size and thread pitch that I have to avoid damaging the the threads in the carburetor.  If it is too long to use with the spring, simply trim the end, reshape and try again until the desired length is obtained.  Before you do this however, get your jetting spot on first because you may not need this mod.

Just to let everyone know, Paul's jetting chart is pretty d**n close.  After jetting my bike by the ride and feel method, I ended up right where the chart says I should be for my altitude and temp.  I am running the fatty pipe but not the Vforce reeds.
Good work Paul!

Offline gowen

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Re: Jetting!!! Again and again and again!
« Reply #94 on: May 24, 2004, 04:43:10 PM »
A NEW THOUGHT!! WHAT ABOUT TIMING?

Well, I took the beast out for a ride at a local called Buckle Berrys. I like that place cause they have a 1/4 mile dirt/sand drag and alot of open sandy land. I took it out for awhile and it ran great! Started 2nd kick (wow! it never started that easy since new) Well, here is the new beef, it had A TON of low-end (constant wheelies) but kinda weak top, would not rev too much, felt like a d**n 4 stroke. I started to race a 4 wheeler, plowed him like parked and the guy said to hold up while he gets his bike, he came back with a cr500! So, we took to a drag, with all low, he got the holeshot and kept a bike length, but all in all, we were even, it all depended on who got the holeshot. Well, I knew I should be eating this d**n little cr500, compared to a KX with all the work I've done and a stock CR. So, I decided I would play with the timing. On the stator, what marks are you guys running? I believe most KX500's have three marks, center is stock. Do most of you guys leave in the center?

I decided on retarding the timing to the third notch and took it for a run, it felt pretty much like normal, kinda quick down low, power shifted down low and it would punch in the mid and wouldn't rev much into the top. So, I then decided to try to go in between the 1st notch and 2nd (center), I took it for a few runs down the drag and it handled great it felt like the top-end had come back and would punch in the top, I decided I was quite happy with it and wanted to advance it to the 1st notch completely. Well, on the way back to my camping spot, the d**n flywheel key snapped (my d**n fault for not tightening the nut enough). So, that ended that. I will make sure to bring alot of them keys next time I make a run. Problem is that it is too hard to get out there (an hour away).

What do you guys think? Especially if you have a hard hitting, high reving 500, do most of you guys keep in the center of the stator?

BTW, advancing/retarding the timing has not helped the idling.

Rick

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Re: Jetting!!! Again and again and again!
« Reply #95 on: May 25, 2004, 05:36:59 AM »
Wow, the responses to this are giong to be interesting.  

I have always run center mark, and never tested to see if there was any improvement with timing changes.  However, if your running Chevron pump premium like I am, advancing may cause some unhappy noises, which on race fuel will go away.

Rick

mikesmith

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Re: Jetting!!! Again and again and again!
« Reply #96 on: May 25, 2004, 06:36:54 AM »
I run the stock center mark also.

kawdude

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Re: Jetting!!! Again and again and again!
« Reply #97 on: May 25, 2004, 10:21:49 AM »
Center mark.  I'm too scared to move it.  So why did the bike run better than it did before.  What changed or was it the stator swap?

Offline gowen

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Re: Jetting!!! Again and again and again!
« Reply #98 on: May 25, 2004, 04:44:04 PM »
I changed the stator, which did not help how it ran really I don't think, well, it felt like it did for awhile, then it kinda creeped back into the sluggish mode. I've moved to the retarted notch. I took off tomarrow morning off so I could work on this, I'm hoping to find out what is wrong. I am thinking I may have a  defect carb. I will post in the wanted forum for a carb.

I'll let you guys know tomarrow. Thanks..

Offline gowen

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Re: Jetting!!! Again and again and again!
« Reply #99 on: May 26, 2004, 03:45:46 PM »
Well, I spent from 9:30am to 2:30pm working and tweaking the big K today and have to say, I'm getting somewhere with this jetting!  8)

Having busted another flywheel key this morning, it delayed my riding. But, I was just tweaking and tuning all day anyways. I decided to purchase a handful of diffrent pilot and main jets. Being my goal was shifting the powerband to the top-end, while getting an idle and having crisp responce. Well I achived about 90% of that. I believe it could use a bit more idle. But, here is the case. I started the day reading my service manual, then calling Forword Motion and talking to Eric and Rich for a few minutes. Well, after taking some notes, I hit the dealer for flywheel keys and jets. Setting up my tools, umbrilla (d**n hot), chair and stand, I began my decent in tuning.

I set my flywheel on the retarted section, and bolted the flywheel down using a lock washer and a air hammer with my portable air compressor.  :D (double security and peace of mind)

After a few hours of riding, and tweaking, I decided I would forget anything anybody has told me, cept for Rich and Eric who said that I should lean the bike out as the port job I selected and bore, and go by the seat of my pants. So, starting with a 165 main, 55 pilot, center clip needle, 1.5 turns on the air.  I knew I was rich, so I started the decent, starting down low, changing the pilot to a 52 and turning the air screw slowly until I hit 2.5 not much idle, two puffs and too much d**n fuel. So, next? The needle, I decided to drop the needle a clip, achived a small idle but would die slowly, so I dropped it to the top clip. Idle!  :shock: Without the screw all the d**n way in! After hearing the lovely wonderful idle, I hit the throttle and what a d**n crisp noise I've never heard out of this bike. So, thinking it could be a fluke and just cause it always runs good from a start, I decide to take it for a run, and crap!  :shock: That guy runs, very responsive. But, with the retarted timing, it hits like a freight train in the top-end, but still some sputtering and puffing, having no more needles, I decide to drop the main jet. Yes my friends, I dropped to a 162 and will NEVER turn back. It runs like a bat out of hell and scares the s**t out of me.  :twisted: Not a bit of hessitation. It could use a smaller pilot as the idle is still a little rich. So, I'm thinking maybe a 50 which I do not have. Anyway, I bring a new BR8EIX plug, slap her in, run for a few hours, wfo and trails, pop her out, crisp brown in the center.  :D  :D  :D

I think I still need to lean it up down low, but the rest is just wonderful. I'm finding that maybe the port job on my KX has allowed more fuel to enter while killing the passage for air into the cylinder causing a serious richness problem.

Being everything I've learned from you guys and the wonderful guys at FM, I think I should open a jetting shop. I can't take any more days off this week, but I'm going to, this sunday, maybe kit the drag and trails, I will also pick up some pilots and do further testing.

I run Klotz Super Tech which has like 10% castor, so I'm not too worried about lack of lubrication, but I am very satisfied with the way it is now, but, the pilot can be fixed a bit, as I'm seriously out on the air screw.

Any ?'s or comments welcomed.

kawdude

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Re: Jetting!!! Again and again and again!
« Reply #100 on: May 26, 2004, 03:55:24 PM »
I'm is awe!!!  :o  Interesting.  Before the rebuild mine had a 162m and 62 pilot.  Idled terrible but the top end was lousy too.  It just takes fiddling with it and the time to do it.

What was the air temp when you were doing this???

Offline gowen

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Re: Jetting!!! Again and again and again!
« Reply #101 on: May 26, 2004, 03:59:30 PM »
about 70% humidity and 90 degrees.

kawdude

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Re: Jetting!!! Again and again and again!
« Reply #102 on: May 26, 2004, 04:00:48 PM »
Cool now look at pauls chart... it's right d**n there!!!

Offline gowen

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Re: Jetting!!! Again and again and again!
« Reply #103 on: May 26, 2004, 04:13:50 PM »
Yup! Thanks Paul.. Now, I can't wait to get back on the drag strip with some 4wheelers and that cr500. My bike feels like I just installed a bottle of NOS on it. :-D

Offline gowen

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Re: Jetting!!! Again and again and again!
« Reply #104 on: May 28, 2004, 12:06:42 PM »
Well, I'm gonna try a 50 pilot tomarrow and see the results, then a 48 if needed. I will let you guys know the stats. :-) Kawdude, have you tried any more jetting deals? I'm real curious if it is just me, cause I know you have a pretty much same setup as myself. 520kit that is, which port did you go with?