82 450E Jetting Help Needed - Don't match what's available?

[pete]

Looks like we're going through the same thing at the same time! lol...

i had the same issues after my vacum sync. Im going to go up with my mains to 142.5 and see how that goes. I'm going to leave the pilots as stock as per most peoples advice.
Haven't pulled out the needles yet to see where they are and adjust them...

One more thing, with the colortune, when you hold revs at 3-4k it kinda pops...not sure if its ok, but it worried me!..

Indeed it does! I've been having this issue since I started fiddling with the pilots and it all comes back to my initial "tuning" being done without the engine warmed up and having the idle set to high as a result.

Now that I know how she really runs, I think I'll also be heading back to the stock pilots to check with the Colourtune.

What throttle opening does that popping happen at? And is the popping through the exhaust or carbs?

[oohsam]

The popping is through the actual color tune. Its almost like its the sound of the sparks/combustion hitting the glass window on the plug...very odd. I got worried i'd damage or blow out the glass and kept it tame...

Doesn't happen when a normal plug is in there!

[pete]

Interesting! I'll keep an ear out for that when I finally get around to using mine... I'm really hoping I can get stuck in soon!

[pete]

Got a spare half hour today to get the stock 17.5's back in and set the mixture screws at 2.5 turns out then primed the carbs.

Not sure when I'm going to get time to fire her up and see if the bogging is better but hopefully soon... really want to get her running a lot better before the run on the 5th Feb!

[oohsam]

Did you color tune or not yet ?

I think I know what im doing with the color tune now!

[pete]

Did you color tune or not yet ?

I think I know what im doing with the color tune now!

Nup, haven't even turned the key and pushed the button yet... I'm hoping for some time today but the Mrs needs to take a last minute trip to her parents' place at Bribie so I probably won't have time...

[pete]

Had to duck out and pick something up today so did around 30km round trip to do that and it was night and day difference when stopped at traffic lights. I can now let her idle with confidence she won't stall on me

No time to play with mixture screws and Colourtune today, so the mixture screws are still at 2.5 turns out, but it's running sooo much better with the stock pilots.

It still seems to bog a touch when initially opening the throttle, so I think around the 1/8 - 1/4 throttle I'll find she's too rich on the needle, but the Colourtune should show that up when I get some time to use it... I'm hopeful of next weekend as I'm on call and can't really go anywhere or do much, but we'll see...

[oohsam]

Good work!

[pete]

Good work!

We'll see once I get the Colourtune going

[pete]

Soooo... I've let this thread lapse quite a bit and I really haven't been able to do much more about the jetting yet, although I did have a brief run with the Colortune the other day but just at idle to try to sort out the mixture screws.

What I found was that it was easy to make it rich (yellow flame), but either I have trouble distinguishing between the blue/white (lean) and blue (right on) flame, or else it's really hard to make it run lean at idle.

Thinking about this more, I realised I have CV carbs, and I believe I should be tuning them from the mains down rather than the pilots up...

Can anyone shed some light on this?

I'm thinking with the 8 size up mains I threw in there that if they're too big (as I suspect) then will I be getting too much fuel through all the circuits? If what I've read is right, the pilot and needle circuits will still draw fuel via the main jets in the CV carbs, so I'm assuming that would influence the mixture at idle and small throttle openings.

Have I completely misunderstood/misinterpreted what I've seen around the traps or do I need to change my method and start with the mains first?

[pete]

I'm just temporarily resurrecting this ancient thread for the sake of completeness.

I've spent some time fiddling with the needles this week and have also changed the main jets.

So, as it stands I'm still on the stock 17.5 pilots, the stock needles are raised two notches, and I have 127.5 mains in there.

I haven't run it since putting it the full two notches richer, but at 1 1/2 notches richer than stock, it runs very well except for a slight flat spot just off idle and some stumbling if I hold it at small throttle openings for any period of time. There is also some occasional popping under decel but it's much less than before.