Author Topic: Do i need a bigger main jet?  (Read 16870 times)

wordslinger

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Re: Do i need a bigger main jet?
« Reply #30 on: March 25, 2012, 04:06:42 AM »
...hey streido...it just turned sunday here....


...got jets???


 ???
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zombie

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Re: Do i need a bigger main jet?
« Reply #31 on: March 25, 2012, 06:10:00 AM »
Also i just read online earlier someone said you need to oil the k&n type filters or they dont work properly? Is that correct? If it is what type of oil do i use?
My engine will not run with an oiled filter. Even a little...
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Shaka

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Re: Do i need a bigger main jet?
« Reply #32 on: March 25, 2012, 06:28:40 AM »
My engine will not run with an oiled filter. Even a little...

 ???  What kind of oil are you using?  Never, ever, heard of that?!

streido

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Re: Do i need a bigger main jet?
« Reply #33 on: March 25, 2012, 10:45:01 AM »
No jets yet Word. Im not long up, 10:30am here. Looked online last night for local bike shops but the only place i found thats open today is a Harley Davidson place so doubt theyll have any that suit me, may try tho. Was thinking im prob easier looking for a 1mm drill bit than jets so i may do that instead today and see if that gets me close by drilling out an old 80jet i got lying about. Just having breakfast then im going out to try around a couple of place i know.

« Last Edit: March 25, 2012, 04:12:19 PM by streido »
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streido

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Re: Do i need a bigger main jet?
« Reply #34 on: March 25, 2012, 11:42:09 AM »
Got some 1mm drill bits so im going to try them out on my old 80 jet and see how that runs. Let you know later. Fingers crossed its close.
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streido

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Re: Do i need a bigger main jet?
« Reply #35 on: March 25, 2012, 03:23:43 PM »
So i drilled my jet out to 1mm or a 100 jet and tried it. It does now run with this in and no tape on the filter but felt a little bit of a pulse at full speed and wot, fuel starvation i assumed? Stopped and put tape over 1/4 of the filter and it felt better, still may have had a little pulsing at wot but maybe was just my imagination. Stopped again and put a little more tape on so about 1/3 of the filter was covered and this felt better i thought.

The fact it got better with the bigger jet kinda proves i think i do need a bigger jet still? Maybe order a 102, 105, 108, 110, 115and try those in it?

Im going to replace my stock box and 82 jet back in till i get bigger jets, my top speed was down again but i swapped out my boss for the one i had in my garage which looked better so i need to know if my loss of top end is down to that boss or the air filter and jetting. If i put it back i can make sure my variator is working properly now 1st then try bigger jets in with the open filter.

Just one more thing, where did you put the clear hose from under the front of the old air box? It joins into a block on the bottom of the box and a black breather hose goes into the back of the same block from top of the valve cover. It collects the vapour from the breather in the clear hise normally so i just joined it together without the block? Seemed right? When i went out after half a mike i heard a WHOOSH noise, kinda like a turbo dump valve, stopped and saw the hoses had come apart, luckily the clear hose was cable tied on to the frame. I rejoined them and went again but it still went WHoosh and split apart at the join again. Taped them together and came home. Didnt want to take a chance riding any more in case i wasnt meant to join these hoses, thought maybe the block in the airbox has a release to let air out when i builds up pressure and since i had joined the without a block it may build up pressure and not have any release?
« Last Edit: March 25, 2012, 03:26:46 PM by streido »
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streido

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Re: Do i need a bigger main jet?
« Reply #36 on: March 25, 2012, 05:07:57 PM »
Stock air box back on,82 main jet refitted for now till  i get some jets. Just been out for a run and top end is back to normal.

Here's what i learned so far,

1 - Had lost top end, down 4-5 mph, replaced boss and 5.5g rollers with new and top end back up to 48-49mph(downhill), uphill (steep) 31mph.

2 - Fitted open filter and 88 jet and it died when i opend throttle up,covered 3/4-2/3 of the filter with tape and it seemed better, actually was drivable but not great, top end down to 38-40-ish mph,didnt even try uphill.

3 - Drilled out a jet to 1mm (1oo jet), no tape on filter, felt pulsing at wot at top speed, got up to 43ish mph.

4 - Taped up just over 1/4of the filter, 100 jet,  no pulsing at wot or top speed, felt ok but top end was down to just over 70 km/h,maybe 44-45mph ish downhill,  uphill was same as number 1, about 31-32mph.

So now i guess i just need to find the correct jet size to get it runnig without tape covering the filter without it running lean and hopefully i will get back the top end with the open filter on?  :-\

Going to go order some jets now, hope it works out cos i dont want to run the open filter if it means sacrificing some top end speed.

Let you know in a few days if i get time to try the new jets midweek.
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streido

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Re: Do i need a bigger main jet?
« Reply #37 on: March 25, 2012, 05:13:12 PM »
Oh,and if anyone whos done this mod can tell me about the valve cover breather tube and what they did with theirs that be good too  :)

I still thin it must have some kind of pressure release in the small conection block on the stock airbox that joins it to the clear tube that hangs under the airbox.You know the one that fills up with yellow fluid over time with a bung on the end.

Cheers guys.
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zombie

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Re: Do i need a bigger main jet?
« Reply #38 on: March 26, 2012, 01:34:31 AM »
???  What kind of oil are you using?  Never, ever, heard of that?!
I tried Bel Ray fiber filter oil. It would not even start. Just flooded out. After clearing the filter with brake clean it started right up
I tried to blow the oil off with the compressor but it still choked, and ran way too rich. I dont get it either.
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zombie

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Re: Do i need a bigger main jet?
« Reply #39 on: March 26, 2012, 01:42:08 AM »
Oh,and if anyone whos done this mod can tell me about the valve cover breather tube and what they did with theirs that be good too  :)

I still thin it must have some kind of pressure release in the small conection block on the stock airbox that joins it to the clear tube that hangs under the airbox.You know the one that fills up with yellow fluid over time with a bung on the end.

Cheers guys.
The hose is a breather for blow by in the crank case. It will have positive pressure when the engine is running. What I would do is simply route it to a spot under the scoot so it can drain itself as you run. As long as the hose is more than 8" the will be no trouble.
You are on the right track with the jetting... Start with a 110, and work down in size if the 110 is too rich
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Shaka

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Re: Do i need a bigger main jet?
« Reply #40 on: March 26, 2012, 01:55:01 AM »
I tried Bel Ray fiber filter oil. It would not even start. Just flooded out. After clearing the filter with brake clean it started right up
I tried to blow the oil off with the compressor but it still choked, and ran way too rich. I dont get it either.

Bel Ray specifies that their oil is for foam filters...like a UNI filter
Not really sure if that matters...just saying
I've always used the K&N oil...no problems like that at all.

streido

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Re: Do i need a bigger main jet?
« Reply #41 on: March 26, 2012, 07:49:24 AM »
The hose is a breather for blow by in the crank case. It will have positive pressure when the engine is running. What I would do is simply route it to a spot under the scoot so it can drain itself as you run. As long as the hose is more than 8" the will be no trouble.
You are on the right track with the jetting... Start with a 110, and work down in size if the 110 is too rich

I thought somebody gave Blue into trouble not so long ago for running his agility with the bung off his drain tube at the filter? Sure he was told it can suck dust and crap up into the engine?

Yes it does have +pressure when i ride. If its fine to just tuck it away under my seat beside the other drain/breather tubes thats good news tho, its over 8" long (i say that to all the ladies lol).
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baddi

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Re: Do i need a bigger main jet?
« Reply #42 on: March 26, 2012, 07:58:55 AM »
Umm guys, just want to check: are you and i running the same scooter? :O
Because with a cone filter and even without any kind of filter (yeah, it fell off), the biggest i've been running is 84 and 86, which fits that Kymco states that 82-85 is what the main jet should be (up- or down-jetting according to air preassure, temperature and moisture). 100 sounds more like what you should fit on a 80cc or bigger :S

Wordslinger, it seems like you've changed cylinder and have done several things to your agility. Can you confirm that it's the 50cc engine which is sold in your area, and not the original 80cc engine? :)
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streido

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Re: Do i need a bigger main jet?
« Reply #43 on: March 26, 2012, 08:21:14 AM »
Unless your cone is very small or is part blocked it seems awfully small to run just a couple of sizes over stock Baddi? I run an 82 jet on just my stock air box?

Did you see the quote from the scooter site i put up saying when fitting a cone filter you must upjet between 10-15 sizes at least?

My scoot wont run over 10 mph with an 88 jet in and open filter, it just bogs down and loses all power. A lot better on a 100 jet so somewhere between 102-110 will hopefully be perfecto for me.

Sure Word will be along soon to answer your question, im sure he's still only 50cc tho with no kit, like mine.

Jets ordered, 102, 104, 106, 108, 110. Should get them midweek so hopefully they work out.
« Last Edit: March 26, 2012, 08:31:23 AM by streido »
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wordslinger

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Re: Do i need a bigger main jet?
« Reply #44 on: March 26, 2012, 10:51:35 AM »
Wordslinger, it seems like you've changed cylinder and have done several things to your agility. Can you confirm that it's the 50cc engine which is sold in your area

..to my knowledge, there are no 80cc agilitys sold in the U.S.

..and my engine is stock...

I thought somebody gave Blue into trouble not so long ago for running his agility with the bung off his drain tube at the filter?

..been running unhooked, but still connected at the valve cover and dangling for years...the airbox drain tube is a different tube...

..streido...wow...i thot i was the only one that hadda run that large of jetting with my k&n...
« Last Edit: March 26, 2012, 12:19:22 PM by wordslinger »
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