low end bog with new pipe

[oldyeller]

Got an apex pipe and installed it on our eton..It absolutely killed the power all around at first..I played with the rollers and now it pulls like a freight train but I just can't get it to come out of the hole..It goes about 2-3 bike lengths very sluggishly and then takes off like crazy..I had three 8 gram rollers mixed with three 5 gram rollers originally and then went to all 5 gram rollers which was much better but still not much better on the bottom end..I didn't have any lighter rollers so I took out one roller..It didn't seem to help much but it still gained mph on the top end..The motor obviously likes to rev with the apex pipe...I changed the springs in the rear clutch to the red coloured ones but still no improvement off the line...The motor is stock with the exception of a uni filter and some boyeseen reeds....I would appreciate any advice to get this thing to pull off the line like it does after it goes 10 or 15 feet!

[tyler70t]

Maybe take a look @ your gearing, might want to change that.

[Bill Lemans]

The clutching changes will help find the sweet spot but hows your jetting ? If your putting that race pipe on a stock motor and changed to the uni,you will most likely need some jetting changes.I don't know any specifics about that pipe that but the eton is jetted rich when from factory with a restricted stock pipe.
Do you still have the stock carb on it ?
Run it at that speed then check your plug and see if it's running lean or rich just to be safe.
When you take off is the quad just moving sluggishly or is the motor hesitating and bogging? Without knowing more info it's hard to determine if it's the motor not making the power or if it's the clutch stifling the motor.
Unless your at the way extreme wrong ends of the spectrum on rollers,torque spring and fly springs I haven't found that changing the clutch springs to higher or lower rpm to make a difference in bogging or rippin'. Just made a difference in launching as they change your clutch engagement rpm.If you have a way, way too low set of springs you would bog as you wouldn't have enough power developed yet to move the quad well.I'm not saying it wouldn't make a difference,but if it engaged fine before the pipe, chances are pretty good that's not the problem. Is it worse than it was before the pipe ?It would more likely be in your rollers or your torque spring.
If your torque spring is too weak it will let that belt drop too fast and it would be like driving in a highway gear, especially with the heavy rollers up front.
On our first eton we ran 4.5 g rollers with a 1500 rpm torque and 1500 rpm fly springs.This was on a stock eton with a hetrick pipe, uni filter and different jet(which I unfortunately can't remember)

Just another thought......if your jetting is off and you keep changing the clutching you will get confused on what the real issue is.I'm not an expert like alot of these guys but I have learned some hard lessons on these things so i'm just sharing some thoughts about my experiences.

[oldyeller]

Yes we are still running the stock carb..It has a 115 jet in it (stock was an 85) to compensate for the uni filter we added last year and the entire trans was stock except I had three 5 gram rollers in with the stock 8 gram rollers..It worked awesome like this until I added the pipe..It made it very sluggish everywhere....After I added the other three 5 gram rollers it woke up and started to rev and make some good power..Then I added the three small red springs in the rear clutch thinking I could raise the engagement speed up above the bog.Again it seemed to accelerate harder but still sluggish for the first 15 feet or so....The big torsion spring inside the rear clutch is still the stock one..Should I add the red torsion spring that I got in my clutch kit from hetricks?

[nordic quad]

Try all 6-5g rollers together with your red torque spring to get your clutch and vario to work as a unit,this should work a lot better,try out diffrent roller weights before changing anything else IMO.

[oldyeller]

Is it possible that the higher engagement speed is now causing my belt to already be shifted into second gear before engagement causing my low end problems?...I am used to snowmobile transmissions where the secondary clutch does not turn unless the sled is already moving..

[nordic quad]

Think off all your mods as a power up kit,and the clutch mods will help you unleash the power,the pipe is the most important mod it works in a higher rpm power band,your red clutch springs will raise your stall and the stiffer red torque spring will help you keep the rews up when shifting,lighter rollers will help you reach your power band faster.We had wery similar mods on our Polaris Predator 90,also what pos.do you have on your needle clip?

[nordic quad]

Also try giving Hetrics a call,they may be able to give you an educaded guess on roller weights when you explain them your total mods.Or try Lakes Motorsports they have tuned lots of Etons great people to deal with.

http://www.lakesmotorsports.com/default.asp

Advetisers on this site may also help you out:D

[nordic quad]

Check out this tread.

http://etonracing1.homestead.com/tech.html

[Tommy Warren]

might want to try a larger pilot jet!

[oldyeller]

I did some more experimenting today..I tried running it with the cover off of the trans and revved it up until it just started to move..The belt did not move in the clutches so I think it is staying in low gear until engagement....I also tried taking 3 rollers out of the variator so it only had 15 grams left in it....Didn't make any difference in the bog.....I tried going up and down with the needle and performance suffered either way..I have it in the 4th clip from the top and it worked great there with the stock setup as well.....I tried playing with the idle mixture and it seemed to like it the more I turned it out.Still not very good but a slight improvement....I assume turning it out is richening it?......Tommy might be right about the pilot jet?...Here is a vid of a take off in the back yard...Its a very short strip but you can hear it take off just as it reaches the edge of my garage..


http://i45.photobucket.com/albums/f84/frdnut/th_MVI_5193.jpg (http://s45.photobucket.com/albums/f84/frdnut/?action=view&current=MVI_5193.flv)

[dericsdad]

Did you put the red large torque spring in it yet?

If you did and it is still bogging on take off try this... get the back of the quad up in the air by setting a jack stand under the rear axle carrier.

With the tires off the ground does it still bog when you give it full throttle?

If yes, tell us where your air screw adjustment is. You should never be beyond 2 1/2 turns out. If you are then you need to change your pilot jet.

First decide what carb. you are going to stick with... you mentioned using a 28mm...

Decide that, then dial it in.

Usually a bog just off idle on snap throttle(with wheels supported off the ground) is an idle mixture/pilot jet issue.

Hope this helps!

Dan

[Bill Lemans]

That sounds like a pilot issue. Check your jetting and idle mixture.At that speed your not quite into the needle circuit yet. When it takes off is probably when your in the needle range.
When you had off the ground checking the clutches did it bog ? Did you check the plug ? You can even open your choke a bit while your riding to see if it helps or worsens the situation. If it helps , you may need to go richer.

[oldyeller]

I have not installed the red torsion spring yet..I do not have any more pilot or main jets for the stock carb so I think I will get the parts I need to install the 28mm carb (air filter and throttle cable)and work on that as I intended to switch it out later anyway.....I really do appreciate everyone's input..I would be very pleased with the performance if we could just get it to come out of the hole better..

[nordic quad]

Ok so i found the pilot jets that Lakes motorsports sent me with the Koso pipe kit
for stock carb.
Pilots #25 and #27,5

Main #110 and #115

All the mods in this kit is very similar to your mods.

Even if you change carb you shold also install the tourqe spring to get a good result.:)

[oldyeller]

Thanks very much for that info...I will take a look and see what the stock size pilot jet is...I am already running the #115 main jet so I am probably in the ball park on that one..Maybe just a hair lean..I will change out the stock torsion spring for the red one as well..

PS..I just went out and pulled off the fuel bowl..The pilot jet is a #43 so I assume it must be different than the predator jet?

[oldyeller]

I just installed the red torsion spring and reinstalled all six 5 gram rollers in the front variator....No change..It won't even spin the tires on wet grass with nobody on it!

[nordic quad]

OK you got all the parts in,the fix may be lighter rollers,in any case you shold buy some lighter rollers to mix and match with,a way to find out may be to try with only 3-5g rollers,this is just to see if it winds up faster,if it doesent your carb needs moore fine tuning,with your new set up you may even be running rich with that #43 pilot,if i remember coreckt we got 3-3.8 and 3-4.5g rollers in the kit for the Predator(may have been 3-5g not shure)

[dericsdad]

Put the Koso carb on!

it sounds like your carb is way off on the pilot. And if you plan to put the bigger carb. on anyway, just get it done and tune it once.

Check what jets are in it first... you will probably end up at around a 135-152 main jet (135-145 if it is a power jet carb) and between a 35-42 pilot jet.

I did not catch the numbers of the belt. Can you let me know the size ? Did you get a rear clutch and bell? Are they compatable with one another? Mean mms match up. Just a thought.

[oldyeller]

I did have just three 5 gram rollers in it while I had the stock torsion spring and it did not help..Should I try it again now that I have the red torsion spring?

As for the trans it is all stock eton stuff including the belt(bando something?).I can get the #s for you..The only thing I have played with is the wieghts and springs...

If it wasn't for the low end flat spot I would be happy with the stock carb and kinda wanted to get it working if possible so I would have a baseline to compare the KOSO to....I will definetly try the KOSO one way or the other...It has a #35 pilot and a #135 main..Does that sound close at all to what I should need?

I appreciate the help guys..I know we will get it figured out sooner or later....My son is impressed already with the new mid and top end power..I can't wait to see his face when I get a good bottom end hit too.:eek2:

[Bill Lemans]

Did you try or check the jet size in the stocker ? Were those 35 and 135 jets in the Koso?