My son has an Eton 70 - all stock. I just purchased a Uni airfilter to replace the stock one along with a few new main jets. The stock jet is an 88.
When I intsalled the Uni filter (directly to the carb) I also re-jetted the main to a #90. The problem is that when I increase the throttle, the quad bogs down and wants to die. I tried a #95 and a #100, all do the same thing. I went back to the #88 with the Uni and still, bogs down. Just to male sure I did'nt do anything stupid, I reinstalled the stock filter with teh #88 main jet (stock) and the quad runs fine.
What gives? Does anyone know what # jet to use?

Thanks.

 

their's more to jetting than just changing the main jet, did you change the pilot jet ? what about the needle? when increasing airflow it changes the whole carburator setting not just main jet, the main only works from 1/2 thottle to full trottle, you may need to go bigger on the pilot jet and maybe raise the needle.

 

Unfortunately, jetting isn't as easy at it appears. On my '03 Pred-90, its Main Jet is 82 (factory). After modifying its factory air box (with a much larger pipe / snorkel snokle), I had to run with an 87.5 / 90 Main Jet. (87.5 in the summer and 90 in the winter). I've read many times that a Main Jet size up to 125 can be installed in the Pred-90 16mm carb. If I go above 90 (90 to 125), I have to drill out its main jet size hole. There's a special drill bit conversion table that must be used. And if I go above 100, I may have to drill out its float bowl needle.

For your E-Ton 70, it soulds like you need the drill the factory carb out as well. Yes, a much larger Main jet can be installed but at a certain point, its factory hole (behind the main jet fitting) will stop the extra gas flowing into the carb.

Sorry, I don't know the drill bit conversion chart off hand. I'm sure a carb specialist on this forum can help in this area.

Note: Once you get it to idle and rev up (re: semi running), its air screw may have to be tweaked as well. Possibily its pilot jet may have to be changed as well. Most people start with the main jet sizes, get that stable, then tweak the under 1/2 throttle settings for perfect plug color in all throttle ranges. Its rare that a pilot screw size is dramatically changed.

Hope this helps....

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well i hate to say but you have opened up a big can of worms. it will take between a 110 and 130 main for the quad to run. puttinf a free flowing filter on one of these mini quad stock carbs is a major pain. the stock carb needs a strong air signal to work properly. when you added the uni you took this away. you can get it to run with a very large main but you run into other problems. if you run the quad very long at wot the fuel bowl will drain and the quad will starve for fuel, fix for this is to drill out the seat for the float needle. you will get it jetted right one day and the next when the weather changes it will not run right. best advice is put the stock filter back on or buy a 20mm aftermarket carb kit. i tell you this through much experiance with these little carbs.

Mark

hey spike, im back

 

If the quad will idle, try this. Let it warm up a bit, till the cylinder is hot(3 or 4 min). Then adjust the air screw to obtain the highest idle speed. Since you have changed the air filter I would guess you will have to go in with the screw to reduce the amount of air to the pilot. Make sure you don't tighten the screw into the carb cause that will damage the carb. It also helps if you set the idle speed low while doing this so you can hear when you have reached the highest idle speed by adjusting the airscrew. Then try to run the quad, it might not fall out as much. If it still falls on it's face, raise the needle by lowering the clip one notch. Try to run it again, it should transition to wide open now much better. After you get the quad to go from idle to wide open nice and smoothly it's time to install a new plug and run it wide open a while and check the plug color to select the right main jet. Grey is bad, brown is good.

 

This is a much bigger pain then I wanted to get into. I was having problems with getting too much water through the filter and knowing the stock filter was a little "cheap", I wanted to begin the upgrade process. I read threads that people stated you only needed to change the main jet. I even read it on a Eton distributor Web site. Don't get me wrong, I certainly think you guys are dead on with what your writting, but I'm no "gear head" (no offense). I'm just a 4 wheeling dad who is enjoing time with his son and looking to improve some performance. I do not want to get into drilling my carb or attempting multiple changes to the needle, etc.
I am intersted in what HRQ109 said about a larger carb. If I go to a larger carb with a Uni filter, can I avoid all the needle and jet adjustments? Would I have to be concerned with anything else if I go to a larger carb?
Damn, this is not as easy and it was made out to be.

 

Even with a carb replacement, you still may have jetting issues. Your best bet is to first try to use what you have. Put the uni back on use the #88 main and raise the clip on the needle one or two slots(lean circuit). If that doesnt work make the needle richer by moving the clip down on the needle. The main runs from 3/4 throttle to WOT(wide open throttle) You can adjust that after you get 1/4 to 3/4 throttle working. Make sure after each adjustment to take a plug reading (what color is it). Since the quad idles what color is the plug?

Carburetor Circuits
Air Screw = Idle to 1/8 Throttle
The Pilot (Slow Jet) = 1/8 to 1/4 Throttle
The slide valve = 1/8 to 1/2 Throttle
Jet needle = 1/4 to 3/4 Throttle
Main Jet = 3/4 to Full Throttle

Read 2manytoys Carb HOW-TO for further information.

 

I think you will still have to jet a bigger carb if you get one. HRQ109 is right about the stock carb problems when you use a different filter. I wonder if there isn't a way around it though. It doesn't sound like your trying to hop up the quad for racing, you just want to raise the filter up to keep it out of water etc. I really can't remember what the stock airfilter setup looks like, but do you think you could rotate it up to the right 90 degrees and find a way to hold it there. Just an idea??????
Or is there a way to restrict the Uni? Too much oil, or blocking some of it off inside with a plastic peice of pipe maybe?

 

I would agree with HQR109.

It would be much easier and "much more stable" to upgrade to a 20mm carb. From visual perspective, if one has a bigger mouth to eat food, then one needs a bigger throat to swallow it. Or, the bigger mouth must do more chewing to get the items into a smaller size (for the stock throat). When it comes to carbs, its much more complex than that. But for a person who wants to upgrade and never tweak it again, then one should upgrade to a higher MM carb. 20mm carb seems to be a great choice for many upgraders.

To upgrade the carb, one must upgrade the intake (for larger pipe between the engine block and carb) and one must change the throttle cable. I've been told the 20mm carbs use different size connecting ends within the carbs. If you upgrade the intake, you may also want to upgrade the reeds. Either better reed leafs and/or a new reed block (bigger opening) with performance reeds. Upgrading reeds will enable faster throttle response. And, remove some air flow restriction when going into the engine block.

Hope this helps as well....


Note: Installing a bigger carb, larger intake, larger air filter and better reeds many NOT allow each part to obtain its 100% benefit. The reason is, you're still using a stock pipe. Your engine will be able to suck more air in but it will bottleneck to push it out. With air filter, carb, intake, reed upgrades, many recommend a performance pipe to allow air out of it. If you install a performance pipe, one should also install a Clutch kit. Thus, allowing the engine to Rev more (to "tune" with the new pipe). If you install a clutch kit, then one may have to install an upgraded CDI. Thus, allowing the engine to rev higher then factory. As someone mentioned above, adding more performance to a mini opens up many other "cans of worms". Each brand of mini is different as well.


Hope this helps - some how....

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Those are excellent upgrade tips.

What would be the total cost $$$$ for all the mods you mentioned?


Also why not try to learn a little about jetting and practice with the jets in front of you while you wait for your new parts to arrive.