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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Best way to richen 1/8 to 1/4 throttle? /cgi-bin/YaBB.pl?num=1283436255 Message started by DrunkenDwarf on 09/02/10 at 07:04:15 |
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Title: Best way to richen 1/8 to 1/4 throttle? Post by DrunkenDwarf on 09/02/10 at 07:04:15 Pilot or Needle? -D. Dwarf |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by Oldfeller on 09/02/10 at 07:34:47 From what I understand ... .... the pilot jet and the air setting screw (under the brass plug) controls idle to first cracked throttle, .... the needle height controls to half throttle .... the main jet controls the rest yet "controls" is a relative term as each earlier stage mildly affects the ones that follow it. Go after the needle height first (white spacer mod) then see what you get before going further. |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by ralfyguy on 09/02/10 at 10:41:50 Ok, I know it's a tad off topic, but how was that 5 seconds full throttle and then back to 3/4 throttle and see if it gains speed test again? That was done in top gear I remember, and if it gains speed after backing off a little the main jet is what? Too small or too big? And at what speed/rpm is it recommended to the test? |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by Serowbot on 09/02/10 at 10:47:37 4th or fifth gear,.. accelerate into the power band, then let off just a little (1/8 turn or less)... If you feel a slight increase in acceleration before dropping off.... you are lean on the main jet... Go up one size and test again... Do this on a normal weather day,... extra hot, humid, or cold, etc... will effect results... Do all jetting on normal weather days..... ;)... |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by ralfyguy on 09/02/10 at 11:20:22 Ok I guess I did it right already. Couldn't feel any acceleration while backing off. So seems I'm fine with the stock 145. I had the 150 in before and it fouled the plug. |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by Routy on 09/02/10 at 12:42:43 Speaking from what worked great for me, I'd raise the needle. (wht spacer mod) From what I understand these needles used to have slots w/ a clip for that very same adjustment. I would sure think that changing the main jet would richen the entire range, except for very low speed/idle 3F36333A203733520 wrote:
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by DrunkenDwarf on 09/02/10 at 13:50:49 7C7369726E687B79717F681A0 wrote:
I was under the impression that the exact opposite was true. The amount of fuel flowing through the main jet is being metered by the needle when the throttle is mostly closed. Increasing the size of the main jet shouldn't allow more fuel past the needle. Of course, I'm usually wrong when it comes to carburetors. -D. Dwarf |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by DrunkenDwarf on 09/02/10 at 14:23:40 16353D3F3C35353C2B590 wrote:
76796378646271737B7562100 wrote:
As you can see in my signature, I've already adjusted the needle height once. I can remove one of the three washers and reduce the spacer to 1mm. I just wanted to get some opinions before I went too far. -D. Dwarf |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by LANCER on 09/02/10 at 14:57:23 646D68617B6C68090 wrote:
the pilot jet is the primary control for idle to 1/4 throttle needle jet & jet needle ... 1/4 to 3/4 throttle main jet .... 3/4 throttle to W/O (wide open) *there is of course overlap between the 3 major fuel circuits above, but for basic purposes that is the way a carb works THIS IS THE GENERAL RULE OF THUMB FOR ALL MOTORCYCLE CARBURETORS http://suzukisavage.com/cgi-bin/YaBB.pl?num=1267299409 http://suzukisavage.com/cgi-bin/YaBB.pl?num=1262724030/0 |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by DrunkenDwarf on 09/02/10 at 20:27:20 6F626D6066713134030 wrote:
Thanks for the links. Just to make sure I understand: If I dial in the idle as described in the linked threads and still have "lean hunting" under 1/4 throttle, I should go up one on the pilot jet and re-adjust the mixture screw. -D. Dwarf |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by LANCER on 09/03/10 at 01:58:05 333A3F362C3B3F5E0 wrote:
Thanks for the links. Just to make sure I understand: If I dial in the idle as described in the linked threads and still have "lean hunting" under 1/4 throttle, I should go up one on the pilot jet and re-adjust the mixture screw. -D. Dwarf [/quote] YEP ...when talking about the stock carb, turning the pilot air adjusting screw 'out" (CCW) richens the mixture. You never want to go more than 3 turns out lest the screw drop out on you. If the engine still acts lean at 3 turns out then go up 1 size on the pilot jet and start over with the screw adjustments |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by ralfyguy on 09/03/10 at 04:40:26 Is there a chart for the actual drill size in jets? I wish I could make something between a 52.5 and a 55 pilot. |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by LANCER on 09/03/10 at 05:37:25 32212C2639273539400 wrote:
not sure about a chart...I have vague shadows in my mind but have no idea if it is the chart you want I do not have this info on hand right now but will try to find out. ...ever seen a drill bit small enough to use for a pilot jet ? ? not me there are sets of tiny files, some regular and some diamond coated, but the sets are basically the same size and shape the round pointed file can be used VERY CAREFULLY to enlarge the hole in a jet just keep in mind that the jet is made of brass and is very soft compared to the file insert the point of the file in the hole of the jet and rotate the file with your finger tips GENTLY once or twice and then check it I try to find a wire that just barely goes through the hole of the jet, so I have something to use to compare after each filing...does it go through about the same or is it easier ? if it feels like the hole is slightly larger then install in the carb and test it. the holes are so small to begin with that it does not take much at all to change the fuel flow a LOT, so go slow and easy The first time I tried this I filed the hole until I could SEE that it was larger..... at that point I had already jumped 3-4 jet sizes, so DO NOT GO BY HOW IT LOOKS ...find a wire that just barely fits and judge by how it feels going in and out. |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by DrunkenDwarf on 09/03/10 at 07:02:28 303D323F392E6E6B5C0 wrote:
YEP ...when talking about the stock carb, turning the pilot air adjusting screw 'out" (CCW) richens the mixture. You never want to go more than 3 turns out lest the screw drop out on you. If the engine still acts lean at 3 turns out then go up 1 size on the pilot jet and start over with the screw adjustments[/quote] So, let's say I've got the idle perfect at 2 turns on with the 52.5 and there is still an off idle lean issue. Should I turn out the mixture screw or go up a jet size first? -D. Dwarf |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by DrunkenDwarf on 09/03/10 at 09:58:43 272A25282E39797C4B0 wrote:
I've got a couple questions about these links. First, the stock white spacer in my carburetor was 2.8 mm and the washers you sent me were 0.5mm thick. The end result is the same number of suggested washers, but the thicknesses are different that you posted. Second, what's 4000 rpm in 4th gear work out to be in mph (assume stock tire/belt/etc). -D. Dwarf |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by ralfyguy on 09/03/10 at 10:37:54 30393C352F383C5D0 wrote:
I've got a couple questions about these links. First, the stock white spacer in my carburetor was 2.8 mm and the washers you sent me were 0.5mm thick. The end result is the same number of suggested washers, but the thicknesses are different that you posted. Second, what's 4000 rpm in 4th gear work out to be in mph (assume stock tire/belt/etc). -D. Dwarf [/quote] If it's a 4-speed it is top gear about the same on my 5-speed. And 4,000 rpm on mine equals about 60mph in 5th gear. |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by ralfyguy on 09/03/10 at 10:41:24 6568676A6C7B3B3E090 wrote:
not sure about a chart...I have vague shadows in my mind but have no idea if it is the chart you want I do not have this info on hand right now but will try to find out. ...ever seen a drill bit small enough to use for a pilot jet ? ? not me there are sets of tiny files, some regular and some diamond coated, but the sets are basically the same size and shape the round pointed file can be used VERY CAREFULLY to enlarge the hole in a jet just keep in mind that the jet is made of brass and is very soft compared to the file insert the point of the file in the hole of the jet and rotate the file with your finger tips GENTLY once or twice and then check it I try to find a wire that just barely goes through the hole of the jet, so I have something to use to compare after each filing...does it go through about the same or is it easier ? if it feels like the hole is slightly larger then install in the carb and test it. the holes are so small to begin with that it does not take much at all to change the fuel flow a LOT, so go slow and easy The first time I tried this I filed the hole until I could SEE that it was larger..... at that point I had already jumped 3-4 jet sizes, so DO NOT GO BY HOW IT LOOKS ...find a wire that just barely fits and judge by how it feels going in and out.[/quote] That is a good idea with the file. But like you said, VERY easy to got too far rather quickly. I had a similar idea, but kinda chickened out to try that. I am a precision machinist from Germany, relocated to the US without a shop and any appropriate tools, due to lack of space and funds. Very frustrating if you know what to do, but can't because of those restrictions. I miss working in a good shop, especially my lathe. >:( |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by ralfyguy on 09/03/10 at 10:45:56 I wonder if the pilot sizes specify the drill size. Looking through a 55 pilot jet it almost looks like it could be 0.55mm. At least it isn't far from it. |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by DrunkenDwarf on 09/03/10 at 11:59:51 697A777D627C6E621B0 wrote:
It's a 5 speed (see sig). So 60mph is about 4,300 rpm in 4th. -D. Dwarf |
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Title: Re: Best way to richen 1/8 to 1/4 throttle? Post by ralfyguy on 09/03/10 at 12:37:28 That sounds about right, maybe a little more. I done my test in 5th gear. Shouldn't make much difference. I just didn't wanna get too fast doing it, that's why I did it in 5th. |
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