Will someone please help me with set up numbers

[racing promotor]

Didn't change rf camber but did move my rr in 1/4 inch. seemed to solve the problem. Tried a new set of wheels this time with correct stagger. Was like a new kart. Handling is much better but still having some rear wheel hopping on exit. Getting conflicting input. Some tell me the wheel hop is due to too little air and kart is too tight and I should go up in air pressure. Others tell me it is the opposite. That the kart is loose and trying to grip. Which is it? Secondly, having trouble getting motor to turn. ran 15-66 and only got 6300 rpms. went up on air pressure and to 15-68 and got 6600 rpms. everyone else is turning 15-64, 15-65 and turning 6800. My motor doesn't seem to be able to do that. Thought it was the timing. have cl3 cam and billet flywheel with built in 32 degrees, with a stock key. In my motor however the stock key gives me 34 degrees. I tried retarding the timing with a number 2 key put in backwards, but motor only turned 3800. Everyone told me to advance the timing using a number 7 key. I tried that and with 15-66 motor would only turn 6100. with 15-68 and more air it turned 6600 but I was way off the pace. Any ideas as to where my timing should be?

You'll NEVER turn RPM when kart or tires or both are not right, loose has nothing to do with the hop, they might be just not explaining themselves properly, the hop is the tire grips releases grips then releases creating a rhythm thus the bounce, just the fact your chasing RPM and the kart is hopping tells you it's to tight, I'd say your giving credit to a change that did nothing moving the RR in did not help it was the stagger change the helped, test by moving RR back out, bottom line you need to free it up to get rid of the hop, little more left maybe, lower VCG maybe, but you need to increase the RF camber also.
Put a 15-65 on it and let it alone FORGET about the motor and gearing for now or you'll chase your tail for months, let the gearing alone and fix the chassis set-up the RPM's will follow.

Good Luck !!

 

[jamtinsl3526]

Set your engine timing at 32-34 degrees and leave it alone if using the CL3 cam....dont go by what everyone tells you because each engine can be set up with different timing depending on how their carb is setup and the rest of their build. Get timing to 32-34 degrees and aim for 6700-6800 as your target rpm with the CL3 cam...change valve springs to fresh springs every 5-6 races. That should get your engine really close, you may or may not need to adjust carb jetting after changing the timing...i suggest getting in touch with Jerry at Dover Power and order his Holey Moses carb for your engine once you get the timing set where it should be, Jerry can set it up exactly for your engine for the area you race in if you tell him the altitude where your track is located. Hope this helps.....one thing to keep in mind is that you cannot always trust what people at the track tell you when it comes to information, especially when you are their competition!

Yeah my carb has had absolutely nothing done to it. reamed out idle to .030 over and running a .038 jet. That's it. Could it be my carb that is preventing the motor from turning 6800 on a 15-64. I cant even turn 6800 on a 15-68. I only got to 6600.

 

[alvin l nunley]

Yeah my carb has had absolutely nothing done to it. reamed out idle to .030 over and running a .038 jet. That's it. Could it be my carb that is preventing the motor from turning 6800 on a 15-64. I cant even turn 6800 on a 15-68. I only got to 6600.

In that ratio range, with a 15 driver, if you add one tooth to the axle, you need to pick up 100 RPM to be going the same speed as before. You added four teeth to the axle, so in order to be going the same speed you need to pick up about 400 RPM. Obviously, if you didn't pick up 400 RPM, you're now going slower on the top end. Of course four teeth should help you out of the corners!

If it was me, I would get that engine on a dyno and find out where the power range is. Obviously your engine is not creating enough horse power to turn more RPM. Why it's not producing enough horsepower is anybody's guess. I'm sure you know there are many many reasons why there's not enough horsepower. One of those reasons could be jetting. I seriously doubt that a .038" jet is ideal in all conditions. And I stress, "all conditions". Air density has a big effect on jetting. Longacre, in their catalog online, says a 1% change in air density calls for a 1% change in jet size. Problem with that carburetor is, changing from a .038" to a .039" is a little over a 5% change in the area of the hole. MSC cells reamers between those two sizes, it's something you might try. If you check the reamers in both decimal and metric sizes, there may be three or four sizes between .038" and .039".

For myself, personally, I would never go racing without an air density gauge. A word to the wise!!!! At the Paris track in California, which is kind of on the edge of the desert, I've seen the air density change 7 to 8 points from the late afternoon to the early evening. I'm sure you can understand that the jet that is good in the afternoon is not gonna be good in the evening.

 

[jamtinsl3526]

your numbers don't seem way out of the ball park. Too little rf camber will make you loose middle/off, bump that up. Bring in the rr wheel closer to the frame, narrowing the rear track width. Only go 1/4" at a time. A little does a lot.

Those two things will tighten you up coming off, without hurting you too much on entry

i had a close look at the winners kart and they have 3 washers on the bottom of the left front spindal and 3 washers on the top of the right front spindal. I have 6 washers on my left front bottom and 13 on my rightfront top spindal. I thought about duplicating that set up since the kart is so much faster than everyone else but i feared that i would loose my entry ability. If i did try that what can i expect to change in the handling of the kart? Any suggestions? Should i try it or stay where im at and work on my motor problems?

 

[XXX#40]

Front 45.9 %
Left 57.3 %
Cross 56.7 %
Total 426.5 LBS
LS Camber +.25
LS Castor - 1
RS Camber -2.40
RS Castor -5.5
Rear Track 40 inches

something is amiss 13 washers on top of the RF your cross would be much higher
Caster is way out of the ballpark of course it turns in good.
Set caster back to stock location, get nose weight above 46% and cross closer to 54% it will still turn in good.

 

[XXX#40]

Sorry I didnt catch the pm
But heres some info left off your post

Will be running indoors on a approximately 12th mile, medium bite, dirt track with some banking in the corners. Driver weighs 175 and running in the stock appearing class.

Way off on gear, and stagger
drop the front driver 2 teeth
Get rear track closer to 38.75
increase rear stagger to 1 1/4 to 1 1/2

 

[alvin l nunley]

I thought about duplicating that set up since the kart is so much faster than everyone else but i feared that i would loose my entry ability.

Fear not, try everything, that's how we learn.

Besides that, it may be where he has to put them to get his weight right, and who knows, his kart may be bent a bit. His tires may be different sizes than yours.

 

[racing promotor]

Don't let someone else get you off focus, you now have Jamie's EAR use it, and try exactly what he tells ya and you'll get your program improved the quickest.

Good Luck !!

 

[jamtinsl3526]

Set your engine timing at 32-34 degrees and leave it alone if using the CL3 cam....dont go by what everyone tells you because each engine can be set up with different timing depending on how their carb is setup and the rest of their build. Get timing to 32-34 degrees and aim for 6700-6800 as your target rpm with the CL3 cam...change valve springs to fresh springs every 5-6 races. That should get your engine really close, you may or may not need to adjust carb jetting after changing the timing...i suggest getting in touch with Jerry at Dover Power and order his Holey Moses carb for your engine once you get the timing set where it should be, Jerry can set it up exactly for your engine for the area you race in if you tell him the altitude where your track is located. Hope this helps.....one thing to keep in mind is that you cannot always trust what people at the track tell you when it comes to information, especially when you are their competition!

I ordered the carb and head kit from Dover and will see if that helps my motor problems. Jerry suggested that I run a # 3 key with my arc billet flywheel. The flywheel already has 34 degrees timing with a straight key built into it. (According to degree wheel not a timing light) Also got a good look at winners front end. Left side has 3 washers on bottom of spindal and right side has 3 washers on top of spindal. My kart has 6 washers on top left and 13 on top on right spindal. I was considering trying to duplicate that setup since that kart walks off and leaves everyone, but I fear that such a drastic change will cause major turning problems or pushing. What do you think? What can I expect the karts handling to change too if I were to make those changes? Will it turn better or worse? Will it develop a push? Will it cause a loosness or tighten the kart?

 

[jamtinsl3526]

Set your engine timing at 32-34 degrees and leave it alone if using the CL3 cam....dont go by what everyone tells you because each engine can be set up with different timing depending on how their carb is setup and the rest of their build. Get timing to 32-34 degrees and aim for 6700-6800 as your target rpm with the CL3 cam...change valve springs to fresh springs every 5-6 races. That should get your engine really close, you may or may not need to adjust carb jetting after changing the timing...i suggest getting in touch with Jerry at Dover Power and order his Holey Moses carb for your engine once you get the timing set where it should be, Jerry can set it up exactly for your engine for the area you race in if you tell him the altitude where your track is located. Hope this helps.....one thing to keep in mind is that you cannot always trust what people at the track tell you when it comes to information, especially when you are their competition!

I got the HM carb and head from Dover and ran better. Instead of last I finished 3rd in the money but still only turned 6100. I was on two teeth less than when I was turning 6600 and running in the back. Went up 3 lbs on air but still have a hop in the corners exiting. Any suggestions as to what I can do to help stop the hop? I still say my front is too tight and the cause of most of my problems.

 

[racing promotor]

I got the HM carb and head from Dover and ran better. Instead of last I finished 3rd in the money but still only turned 6100. I was on two teeth less than when I was turning 6600 and running in the back. Went up 3 lbs on air but still have a hop in the corners exiting. Any suggestions as to what I can do to help stop the hop? I still say my front is too tight and the cause of most of my problems.

Are you still on low RF neg camber ? If so increase it first, other suggestions lower VCG, Increase left side % age, you can speed time and MONEY on the motor until the cows come home, IF the chassis and tires are NOT correct you'll chase RPM till it drives you crazy !

 

[alvin l nunley]

I got the HM carb and head from Dover and ran better. Instead of last I finished 3rd in the money but still only turned 6100. I was on two teeth less than when I was turning 6600 and running in the back. Went up 3 lbs on air but still have a hop in the corners exiting. Any suggestions as to what I can do to help stop the hop? I still say my front is too tight and the cause of most of my problems.

Is that two teeth on the axle or on the driver? Two teeth on the axle should be about a 200 RPM difference, while two teeth on the driver should be about an 800 RPM difference. I say "about" because it does depend on what your gear ratio is to start. Either way it makes me wonder why your engine changed 500 RPM.

 

[jamtinsl3526]

Is that two teeth on the axle or on the driver? Two teeth on the axle should be about a 200 RPM difference, while two teeth on the driver should be about an 800 RPM difference. I say "about" because it does depend on what your gear ratio is to start. Either way it makes me wonder why your engine changed 500 RPM.

It concerns me too. It was two teeth less on axle. Ran 15-68 last time and turned 6600 ran 15-66 this time and turned 6100 but was much faster even though I turned less. Only difference was I bought the Dover Holy Moses carb and head kit. Started out on 15-65 in practice and only turned 6100 when the track was tacky scared me so I went to 66 and still only turned 6100 when the track was fast. Has me wondering if I'm concerned too much with rpms. Maybe my motor just don't wont to turn more than that. Is it possible my motor only makes power in that rpm range. Have a buddy who had a motor. His engine builder said to turn it 67-6800 but he said when he did he was bringing up the rear. Said when he ran it at 61-6200 it ran like a scalded dog.

 

[jamtinsl3526]

Is that two teeth on the axle or on the driver? Two teeth on the axle should be about a 200 RPM difference, while two teeth on the driver should be about an 800 RPM difference. I say "about" because it does depend on what your gear ratio is to start. Either way it makes me wonder why your engine changed 500 RPM.

Just discovered somethin new. My tattle was going off crazy last night even though it says I only turned 6100. Checked tattle and it is set at 6700. So I must have been turning at least 6700 and probably much more. Tattle was going off 3/4 of the way down the track. Don't understand how tattle can be accurate but memory max rpm would be much different. Tach must be giving me bad info. Anyone else ever had this problem? Is there something I can do to correct it?

 

[jamtinsl3526]

something is amiss 13 washers on top of the RF your cross would be much higher
Caster is way out of the ballpark of course it turns in good.
Set caster back to stock location, get nose weight above 46% and cross closer to 54% it will still turn in good.

Jamie I'm having trouble getting the kart to the numbers you suggest. When I get the kart to 54% cross my RF camber is maxed out at -2.5 When I move a washer to get the camber to -3.0 my cross goes up to 57% my nose stays around 46%. How can I fix this and are you sure 54% is enough for someone who weighes 230lbs? Because of my weight I am usually tight so I figured I would need much more cross than that but I'll try your suggestions but am having trouble getting there.

 

[XXX#40]

Jamie I'm having trouble getting the kart to the numbers you suggest. When I get the kart to 54% cross my RF camber is maxed out at -2.5 When I move a washer to get the camber to -3.0 my cross goes up to 57% my nose stays around 46%. How can I fix this and are you sure 54% is enough for someone who weighes 230lbs? Because of my weight I am usually tight so I figured I would need much more cross than that but I'll try your suggestions but am having trouble getting there.

You have a problem with the RF Spindle L block combo ie.. 10 degree L block 15 deg. spindle.
Or something is bent, you should have no problems getting 54% cross and your camber settings without extreme washer placements.
8 washers on top of the left spindle and 8 on bottom of the right you should be near 54% cross.
check the camber, you should have plenty of adjustment if not i'd look at the RF closer to find the problem

 

[racing promotor]

When I move a washer to get the camber to -3.0

Jamie am I reading this wrong or missing something here ? move washers to get camber ?

 

[XXX#40]

When I move a washer to get the camber to -3.0

Jamie am I reading this wrong or missing something here ? move washers to get camber ?

think he means when he maxes out the washers he has low camber because of being maxed out on camber adjustment

 

[jamtinsl3526]

think he means when he maxes out the washers he has low camber because of being maxed out on camber adjustment

Exactly. Got camber to +.25 on left and -3.0 on right with 57% cross and 57% left with 46% nose. That's the best I could get. When I get 54% cross the best I can do on camber is -2.5. Kart seems tight and still has a hop.