Author Topic: Carbureted: Modified vs.Stock settings on a Daytona Tw Tec tuner?  (Read 200 times)

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Offline Sinn

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Modified vs.Stock settings on a Daytona Tw Tec tuner?
« on: October 29, 2017, 08:55:10 AM »
 Hey can anybody give advice on the difference between the stock Street settings and the modified settings on the Daytona twin tech ignition 1008 TC 88.  I have a 2000 electraglide with a 103 built motor,  with screaming eagle flattop pistons, polished but not ported stock heads, 570 S&S gear drive compression release cams, and true tools with Vance and Hines slip on's, and a making 42 mm carb.  I'm running a 20 pilot, 97 needle on the second needle position 160 Main jet in the 70 pump. And running NGK sparks I mostly run 90+ octane gas.
My problem is I can build a motor but when it  comes to spark and fuel I'm a little less smart. I went through the Daytona  website and there a manual pretty meticulously. I noticed that stock settings are 1, 5,5.  And the modified curves use 1,2,2.to start. I don't know if I would consider my engine highly modified but  I have used both starting points and neither seem to feel real goods a starting point  The reason I'm writing is I've had issues with this motor for a while running to lean on the Dynatech 2000 ignition the result was burned off piston skirts so I'm a little leery about a starting point any help would be appreciAted
« Last Edit: October 29, 2017, 03:28:24 PM by Sinn »

Offline PC_Hater

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Re: Modified vs.Stock settings on a Daytona Tw Tec tuner?
« Reply #1 on: October 30, 2017, 08:13:02 AM »
I think the problem is your carb settings, not the ignition.
My bike is still a stock bore and compression 88" with an SE Air Filter, Andrews TW21G cams and a Supertrapp 2:1 with 13 discs and a closed end cap. A very mild and quiet build.
The settings on the Mikuni HSR42 on your bike are the same as mine! (apart from the accelerator pump - I have 50 fitted).

Set the Daytona Twin Tec ignition to the stock 1,5,5 and leave it like that until somebody gives you a good reason to change it.
Download the Mikuni HSR Tuning Manual and start richening things up a bit.
I have no experience tuning Mikuni carbs, I did what the installation manual said and it works.

A search through this site, the various dyno runs etc should give you some ideas as to whether you can get away with just a bigger main jet or you need a richer needle too. A trip to the dyno-man will save you a lot of hassle.

Hopefully somebody that knows what they are doing will comment.
« Last Edit: October 30, 2017, 08:17:32 AM by PC_Hater »
1942 WLA45 chop, 1999 FLTR(not I), 2000 1200S