[Nick_R_23]

So I finally got my raptor together and got to start it! It sounds good but Im having a little trouble with the carbs still, I think.

It will start up and run, but idle a little high. I have some slack in the cable and the idle screw all the way out. I havent checked for a vaccuum leak yet but that is my next step.

If I try and give it any gas, it pops a bit and wont rev up much, and it acts like its really cold. Might even die if you try and give it too much throttle.

If I just let it sit and idle itll run for a bit, then just die. If you try and start it right back up it wont, but if you let it sit for like 30 seconds it will start up fine. Almost acts like it runs out of gas, and has to fill back up.

I have a DJ jet kit, Curtis Sparks exhaust, K&N filter with drilled airbox, Stage 1 Hotcam. Around 2-300' elevation.

DJ needles are at 3rd clip from the top, DJ146/DJ148 Main Jets, #25 pilots, fuel screws are at 2-1/4 and 2-1/8. I just put brand new needles and seats in, and reset the floats.

Any ideas?

 

[willykiller]

Vacuum leaks, PB rev limiter and improper jetting come to mind.............

 

[Nick_R_23]

Vacuum leaks, PB rev limiter and improper jetting come to mind.............

PB and Clutch switches have both been removed.

 

[willykiller]

PB and Clutch switches have both been removed.

Okay then, a grounded green and yellow wire or also an open green and white wire will turn on the rev limiter for their perspective circuits.............

 

[Nick_R_23]

Okay then, a grounded green and yellow wire or also an open green and white wire will turn on the rev limiter for their perspective circuits.............

I don't remember which one was which now, but in the tutorial I know one had to be simply disconnected, and the other had to be connected together, and that's been done.

 

[QuadManiac]

Did you just put new 25's in, or could the pilots be dirty? How long since they've been cleaned? Certainly, make sure the carbs are fully mounted and tight.

 

[QuadManiac]

I don't remember which one was which now, but in the tutorial I know one had to be simply disconnected, and the other had to be connected together, and that's been done.

He's talking about the reverse switch wire - green/white wire down at the output sprocket - ground it... You unplugged the PB switch and connected together the clutch switch wires - different things.

 

[Nick_R_23]

Did you just put new 25's in, or could the pilots be dirty? How long since they've been cleaned? Certainly, make sure the carbs are fully mounted and tight.

Everything carb related is brand new, including the pilots, 0 hours on anything.

Also just checked for a vacumm leak, and couldn't find one. Hooked up a vacumm gauge and its holding steady a 10", and drops when I try and rev it up.

 

[Nick_R_23]

He's talking about the reverse switch wire - green/white wire down at the output sprocket - ground it... You unplugged the PB switch and connected together the clutch switch wires - different things.

Sorry, got confused there. I have a brand new harness that runs down to the reverse and neutral switches as well.

So I want to ground the green/white wire then, and see if the problem goes away, correct?

 

[QuadManiac]

Yes, ground the green/white wire, just to make sure a bad connection or switch isn't turning on the reverse RPM limiter.

Honestly, I hate DJ mains, not because they are of poor quality, but just because their numbering system doesn't jive with Mikuni's, what most of us are used to.

With your mods, I'd suggest 160L/165R Mikuni mains, 25 pilots and a DJ needle about half way, and fuel screws around 2 turns or so... so except for my not knowing if you have the correct DJ mains, you seem pretty close everywhere else.

If the cable is slack and the idle speed screw not contacting the throttle cam, yet idle speed is high, you may have a vacuum leak, or the choke plunger may be stuck... also your slides may be sticking or a slide diaphragm leaking - check them carefully for nice, smooth return to closed when you lift and let go; pull the top covers and verify that the diaphragms are not pinched, cracked or leaking in any way...

 

[Nick_R_23]

Ill go out and try grounding the wire.

These carbs did have Mikuni 160/165 mains in them before, but I swapped them out for the DJ mains according to their jetting sheet.

 

[QuadManiac]

BTW, I meant mains, not needles - the cross reference is non-existent - what is published is just plain wrong.

But, what you're seeing (problems at idle for starters) is not related to mains... it has to be a leak, a plugged pilot jet, a stuck choke plunger, or some other issue... once that's fixed, then performance issues when you come onto throttle can be worked out.

Did you use the clear tube method to set float levels?

 

[Nick_R_23]

I have the choke cable backed all the way off to eliminate that. The plunger appears to be in good shape. If I pulled the choke while its running, it speeds the engine up.

The slides move freely, but Ill pull them out and double check for anything I may have missed.

I set the floats by the manual, 13mm float height from the edge of the bowl.

 

[Nick_R_23]

Ok, I grounded out the green/white wire and it helped some. It stills starts and idles really high, but I can rev it up now with only a minor pop. Before, it wouldn't rev up at all, and pop, stutter, and backfire when I tried to.

 

[willykiller]

Ok, I grounded out the green/white wire and it helped some. It stills starts and idles really high, but I can rev it up now with only a minor pop. Before, it wouldn't rev up at all, and pop, stutter, and backfire when I tried to.

So most likely now it is jetting related where as before, it was both, elctrical and jetting from the sounds of it...........

 

[Nick_R_23]

So most likely now it is jetting related where as before, it was both, elctrical and jetting from the sounds of it...........

So does grounding out the green/white wire simply mean the switch it was connected to is bad?

 

[willykiller]

So does grounding out the green/white wire simply mean the switch it was connected to is bad?

Grounding the green and white wire turns off the reverse rev limiter, grounding the green and yellow wire turns the park brake rev limiter on............

 

[Nick_R_23]

Ok, I tested the reverse switch and it grounds out in neutral (Im assuming this is what its supposed to do-turn off the limiter out of reverse?), but when I plug the wire in, it cuts out again.

Also, my vacuum gauge is now rapidly vibrating between 8-12".

 

[Nick_R_23]

I made a little more progress. I put some clear tubes on the float bowls and found that the right side wasn't filling up with fuel properly. Took them apart and readjusted both floats, and now both sides sit about 3mm above the float bowl mating surface. It starts and runs and sounds a lot better.

Now, if I rev it up, itll rev very nice with only just a real slight pop. But when I let off, it goes back down to the high idle I had before. But if I lightly hit the throttle once or twice, it kicks down to a lower idle, but it is still high.

When its at the higher idle, the vacuum gauge has a 4-5" rapid fluctuation, but when it kicks down, it rapidly fluctuates between about 5 and 25".

 

[willykiller]

I made a little more progress. I put some clear tubes on the float bowls and found that the right side wasn't filling up with fuel properly. Took them apart and readjusted both floats, and now both sides sit about 3mm above the float bowl mating surface. It starts and runs and sounds a lot better.

Now, if I rev it up, itll rev very nice with only just a real slight pop. But when I let off, it goes back down to the high idle I had before. But if I lightly hit the throttle once or twice, it kicks down to a lower idle, but it is still high.

When its at the higher idle, the vacuum gauge has a 4-5" rapid fluctuation, but when it kicks down, it rapidly fluctuates between about 5 and 25".

This means she is running lean at idle speeds...........