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TOPIC: Re:dynojetting
#1029121
Ian Pemberton (User)
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dynojetting 1 Week, 1 Day ago  
Hello again,I would like some advice for getting my bike properly dynojetted.
I have fitted a spike air filter and Vance & Hines short shots(baffles in)along with Harley torque cones in the headers.
All seems fine except for a slight flat spot low down the rev range.
I am going to take the bike to a dynojet specialist this spring.My question is this;What set up would set up should I ask for to get the most out of the bike(low down torque,cruisingand top end performance,while not affecting mpg too much)?
Any other ideas on how to increase the performance much appreciated.
Thank you
 
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Last Edit: 2018/02/15 15:38 By Ian Pemberton.
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#1029128
BikerRon (User)
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Re:dynojetting 1 Week, 1 Day ago  
Porting the manifold is always a favorite around here.

Seems simple enough.
 
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#1029130
SKWEARpeg (User)
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Re:dynojetting 1 Week, 1 Day ago  
Assuming a 1600??

37.5 Mikuni Pilot N224.103..........no, a Dynojet 37.5 Pilot is not the same size. The DJ 37.5 Pilot, is the same as the stock 35 Mikuni.
167.5 or 170 Mikuni Main jet.

If your bike is a Wildstar, I'd have a look at the needle that is under the slide now. It may already be a muti-groove, as stock. If so, you can lower the clip a notch and try it. Or, add another shim under the clip(you would have two shims and the fat plastic spacer under the clip). Lowering the clip one groove, would be a full step richer in the transition. Adding a second washer, would be a half step richer. Either one or the other. Don't do both.

The 37.5 will give you more available fuel in the Pilot circuit, for off idle throttle help. This, combined with a slightly richer setting on the needle, will bring more fuel earlier in the transition, also. That should help with any off idle flat spots.

The 167.5 or 170 Mikuni mains, will give you extra fuel on the top end.........again, the Dynojet mains, will be smaller then the Mikuni's, if you try and substitute a 167.5 or 170 DJ main. See the comparrison chart between DJ and Mikuni jets, on the Tech Articles page.
 
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#1029164
Ian Pemberton (User)
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Re:dynojetting 1 Week ago  
Its a 1700. I think stage 2 tune is what I'm after
 
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#1029168
SKWEARpeg (User)
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Re:dynojetting 1 Week ago  
Pick up a Barons kit with the new multi-groove needle and Mikuni Main.

172.5 Mikuni Main.
40 Mikuni Pilot.
4 th groove from the top on the Barons needle, with the stock stack up(fat spacer and single shim under the clip).

Do that, and save the “Specialist” money for a decent pole dancer.
 
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#1029178
davej (User)
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Re:dynojetting 6 Days, 14 Hours ago  
SKWEARpeg wrote:
Pick up a Barons kit with the new multi-groove needle and Mikuni Main.

172.5 Mikuni Main.
40 Mikuni Pilot.
4 th groove from the top on the Barons needle, with the stock stack up(fat spacer and single shim under the clip).

Do that, and save the “Specialist” money for a decent pole dancer.


Also turn the PMS screw 2 - 2 1/2 turns out and set the idle to 900-950 rpm when warmed up. This jetting is for a 1700 and has been dyno proven to be the best all around jetting for a 1700. It will get you the best performance available from a stock 1700 bike with intake and exhaust mods like you have. When I say performance I'm also talking about MPG along with HP/TQ. This proper tuning will get the best of everything.
 
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#1029179
SKWEARpeg (User)
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Re:dynojetting 6 Days, 12 Hours ago  
That proper rpm setting on a hot motor, can’t be stressed enough. Set it, and leave it alone. Folks like to turn the idle down to 650 or so, and then wonder why the bike stumbles when they pull away from a light.
Also, resist the temptation to treat the throttle like you own a Maserati. If you do fast repetitive twist of the throttle trying to impress the heavens, it’ll snort at you.
 
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#1029195
Ian Pemberton (User)
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Re:dynojetting 6 Days, 2 Hours ago  
I have already changed the jets,172.5 main,and 40 pilot.It still has the slight stumble at low revs and I'm not snapping the throttle open.I think maybe blocking off the AIS may help.Is it right that a golf tee stuck in the pipe works?
I live in Wales and can't get the Barons kit over here.
Thanks
 
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#1029196
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Re:dynojetting 6 Days ago  
Where’d you get the jets? You’re good there. Make sure the idle is correct.
Find a washer the same size as the silver shim under the clip, and add it to the existing shim and fat plastic spacer. That should richen the transition a bit and may help. If it does, but you’re still not happy, try adding another washer to the same place. Some kits only use washers. The multi groove needles make for a cleaner set up, but adding the washer(s) to the stack up does the same thing.
You can make block off plates to replace the AIS connections at the heads, and cap the vacuum port on top of the intake manifold. The rest of the AIS can be removed altogether.
Be careful about making things richer, to cover a vacuum leak.
You may need to remove the intake manifold, surface the flange faces, and reseal it. Roadies tend to develop leaks at the flanges. The vacuum leak at the flanges can cause a lean stumble.
 
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#1029206
SKWEARpeg (User)
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Re:dynojetting 5 Days, 12 Hours ago  
Ian, be aware “The Clinic” is shutting down on the 28th of February, for good. The new site which is being set up, is www.roadstarclinic.com. The migration to the new site has begun. Type the addy I provided in your browser search, and it will take you there and you can register and become a member, on the new site.
 
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