IR,wide open throttle employs all your jets ,you have fuel coming in from your idle jet +jet needle +needle jet+ main jet.A 150 main is usually ok ,but if you live at sea level to 1000 ft . you may be still running to lean at WOT .and may have to go to a152.5 main. the way to test your main is to get the bike pulling hard with wot,then back the throttle off about 1/8,if the bike speeds up the main is to small(it's going lean) if the motor bogs the main is to large(it's going rich)if neither you have the correct size.you should use the smallest jet possible to get your bike to run well ,as larger jets decrease your mpg.

OK I don't have the Dyna in yet, but with the same weather, I'm running a 145 main and a 55 pilot and I've done the WOT then back off thing and it's pulling like a maniac with no surging upon 1/8 closure. Before I went to the 55 pilot from the stock 52.5 there was surging at low rpm. Now it's as smooth as silk pulls all the way from fully shut to wot with no surging or backfiring or pooting upon shutdown, plus the engine is running cooler. I'd seriously consider going back to the 55 pilot for another look.

@IslandRoad, I believe that the Dyna breathes better!?, so I'll probably end up with a bigger main and move the needle position, but most local riding at the 60km speed limit is done at under 1/4 throttle and mostly 1/8 throttle, in fact 1/4 will give me 80kph no problems, and this is virtually exclusively the pilot jet from what I'm given to understand and you have the Dyna which at best would not affect the pilot, but more likely would need to go up a size and as I don't have the Dyna and am running with the pilot perfectly at 1 3/4 turns out, I find it peculiar that your stock 52.5 would be fine. And as noted further upthread, the pilot will still come into the mix even at higher openings anyway.

This is what the sound graph looks like after taking it for a five minute ride, it is as even and perfect as it's possible to be at 1100rpm.



P.S, I've decided against the welding as the muffler guy is confident that I'll be happy with his work. This will be happening next week so I'll be able to compare like with like. Although I have ordered a K&N as well got one on eBay with postage included from the U.K for $80 AUD which is barely more than the OEM filter. And $80 is cheaper than you can buy in in America!

Thanks for the advice Dave ☺

I had a feeling the needle spacer could come down a little bit more. I had moved it to the lowest notch on the needle and was hoping to get away with that. Still has a little surging at 1/8 to 1/4 throttle but I've been trying to ignore it. Probably need to reduce the spacer a little as well (I'm having trouble finding washers in the local shops that)

I put the 55 pilot in last night and took it for a good run to warm up the bike and test it, just to see what effect it had. I wouldn't say it ran any better, however it did virtually eliminate the afterfiring (that was nice, but not critical for me). I'm probably at the stage of fine-tuning now.

With the 55 pilot jet the fuel mix screw gives max rpm at about 3/4 turn CCW out from fully in. At fully in,  the idle slows just a little. At 3 turns CCW the bike almost stops.

Whereas, with the 52.5 pilot jet (stock), max rpm is at 1 1/2 turns CCW. The bike almost stops at fully in. And slows down considerably toward 3 turns out.

That seems to me to say the 52.5 is the right pilot jet.

Looks like I'll be reducing the spacer a little.

And I have a 152.5 main jet on order.


Dave wrote on 01/09/17 at 17:55:46:

@Eau, my needle does have three notches for the clip that holds the spacer. Basically, middle is stock, and then one notch each way for leaner or richer. Dave's suggestion is based on using 4 washers to replace the spacer instead of moving the clip. By removing one washer at a time you  reduce the spacer by 1/4 height at a time, so you can adjust in smaller increments.

I was hoping the move to the richer notch would do the job but I think it need a little more. I've  read on these forums of guys experimenting with everything from 3 washers down to no spacer at all.

@Eau, all that matters is how far the needle gets lifted. There's a spring that pushes the needle upward against a plate. The plate has a hole in the top; small enough the catch the spacer, but big enough to let the top of the needle through. The white spacer sets the limit for how high it lifts.

Reduce the size of the spacer - the needle will push up higher.
Move the spacer down a notch - the needle will push up higher.

I assume any combination of the two would also work.

I'll post some pictures.

This is the needle, the spring, the clip, and a little washer that sits below the clip.

This is looking down into the diaphragm. The two small screws hold the plate in place.  In order to get the plate on, you have to put pressure on it because the spring is pushing upward against the spacer from underneath. You can see the spacer down the centre, and the needle in the centre of that.

You are doing well "Grasshopper". 🏍😎