I need jetting help

[Tbrock77]

DG pipe and silencer, ported cylinder (bought a motor to use the bottom end and the top end was brand new and ported, looks like a mild port) stock carb with airbox and full lid, 150 psi, 67.25mm wiseco piston, running from 0-1000', temps in the 80s.

Not sure where to start, i looked around and saw 310 might be a good starting spot. Any suggestions are appreciated, thank you.

 

[Herpderplol]

Best starting point is replacing the pipe no offence. DG= DownGrade

otherwise in all seriousness, 310 doesnt sound far off, i would order 270-310 jets

 

[Tbrock77]

Best starting point is replacing the pipe no offence. DG= DownGrade

otherwise in all seriousness, 310 doesnt sound far off, i would order 270-310 jets

As of right now it's that or stock. If stock is better I'll throw it back on haha. It is an older DG if that makes any difference.

 

[Blaaster]

DG = Dont Get, Don't go, Don't grumble.

How did you come to the conclusion it was a mild port job, how much was the exhaust port raised?

Is the lid on the air box, if so a 310 is too big a jet.

 

[Tbrock77]

DG = Dont Get, Don't go, Don't grumble.

How did you come to the conclusion it was a mild port job, how much was the exhaust port raised?

Is the lid on the air box, if so a 310 is too big a jet.

It appears to be just a mild port because the intake was left with only the 2 main holes. The transfers were cleaned up all the way through and the exhaust has opened up. I did not think to measure the exhaust port. It might be a simply trail port, I thought I had taken pictures before I put it on but I did not.

The lid is on the air box. Regular foam filter.

This is my girlfriends quad so I'm not trying to make it deadly fast yet. The one reason that ported cylinder was put on was because she needed a new top end (hers was only making 100psi, new one is making 150)

 

[Blaaster]

If the only mods that you have is the DG pipe which usually calls for a #260 main jet, and a foam filter, I would be starting the plug chop at no more than a #290 main jet.

 

[Tbrock77]

If the only mods that you have is the DG pipe which usually calls for a #260 main jet, and a foam filter, I would be starting the plug chop at no more than a #290 main jet.

It is ported though so wouldn't that call for more fuel?

 

[Blaaster]

Porting will change the air velocity, and the increased speed over the emulsion tube will draw more fuel to compensate.

If the snorkel is still on the air box, and the oil injection is still fitted a #290 should be adequately large enough to do the first plug chop.

 

[Tbrock77]

Porting will change the air velocity, and the increased speed over the emulsion tube will draw more fuel to compensate.

If the snorkel is still on the air box, and the oil injection is still fitted a #290 should be adequately large enough to do the first plug chop.

Okay I'll start there. I got a 290, 280 and a 270 to work with and can get more as needed

 

[Awk08]

Okay I'll start there. I got a 290, 280 and a 270 to work with and can get more as needed

it's good to start large and work down, if for no other reason than to get a feel for a rich condition, but i'm betting you end up smaller than those you currently have, the DG pipe isn't much more than a chrome stock pipe.

 

[Tbrock77]

it's good to start large and work down, if for no other reason than to get a feel for a rich condition, but i'm betting you end up smaller than those you currently have, the DG pipe isn't much more than a chrome stock pipe.

I put the 290 in. I still have to heat cycle this motor and then I'm going to do a plug chop. At idle and just a bit of throttle just to vary the rpm as I do the first heat cycle it is very responsive and comes right back down so I think I have the air screw set almost perfectly. Won't be able to plug chop until late tomorrow or Thursday.

 

[Larry's Shee]

Take your time, do it right, and avoid

"I just want to ride" syndrome !!!​

 

[Tbrock77]

Take your time, do it right, and avoid

"I just want to ride" syndrome !!!​

I've done 2 varying idle cycles so far, I always break my motors in right. It's my girlfriends quad so I'm in no hurry, I have my own haha

 

[Tbrock77]

Alright so I've ran into a bit of a snag. This thing does NOT want to kickstart cold. Kick after kick nothing, pop start it and it runs fine, idles great.

I checked the float level and it was right, cleaned the jets, and used fresh gas and still it doesn't want to kick start. I checked compression (155psi) and tossed in a new plug and still nothing.

I'm 1.5 turns out on the air screw, stock pilot, 290 main.

 

[Awk08]

Is 1.5 turns out the airscrew setting that is producing the highest idle ?

As per the adjusting airscrew/pilot thread in the carb section ?

 

[Tbrock77]

Is 1.5 turns out the airscrew setting that is producing the highest idle ?

As per the adjusting airscrew/pilot thread in the carb section ?

No it is not, I had it out at 2.5 turns and went to 1.5 and it dropped the idle so much it died. I just looked for that thread and couldn't find it. Could you post a link?

Actually found the thread shortly after posting this.

Highest idle is just at 2.5, I took it out and it is just rich everywhere it sound like it is running wet haha it just pours blue smoke and I still have the oil injection on. I never checked the needle so I'm going to see what setting it is on. The 290 main is probably too big, good call Awk

Edit: come to find out its running way too lean. Plug is burnt. I don't understand how it's burnt but it was pouring blue smoke?

 

[Tbrock77]

Here's what the plug looked like. I didn't go above 2nd and not more than half throttle and it was pouring blue smoke the entire time

Edit: I'm dumb and it ran out of fuel so it was just running off the bowl, which caused the lean condition. I just had it running again, it doesn't want to run, pulling the choke causes it to die. I was having problems with this carburetor before. I had stock jets in on a stock quad and it wanted the air screw 4.5 turns out before it would run smooth.

 

[Larry's Shee]

So, do I ask about your avatar here, or in a PM?

 

[Tbrock77]

So, do I ask about your avatar here, or in a PM?

Shoot me a pm

 

[Blaaster]

The main jet will not be giving you any problems until you get above 3/4, throttle, it has no say in the mix until then, that is why a too big main jet is recommended, to avoid the chance of a full throttle melt down.

The problem is either in the pilot circuit or the fuel enrichment circuit.( choke )

Needing the air screw so many turns out points at a pilot jet that is too large, or a float level that allows too much fuel into the carby.

Does the carby seep fuel at all?

The large issue of smoke is possibly a build up of oil in the header pipe being burnt off, and of course a richer than optimum mixture at idle will compound the matter.