rear end ratio selecting
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Instructor
Joined: Feb 2005
Posts: 188
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From: Kearney Nebraska
It was warm enough to take it out today. First changed jets from 82/90 to 87/79 and it would cruise steady around 11.5 af. Then changed jets to 76/84 and it is cruising at 12.2, 12.5 af. This seems about right, but if I accelerate a little or a lot it goes way lean and starts to cut out. I have 50cc pumps on prim and sec. The shooters on it now are .037/.040. Would the next thing to try be a more aggressive cam for the primary shooter? If I had a vacuum leak would the symptom be this problem of going lean during acceleration? I have a line going from the valve cover to the back of the carb and another line that attaches to the vacuum accessories. It takes 2-3 minutes for the headlights to open after starting the engine and it makes me think there could be a leak somewhere.
Last edited by big69; Jan 2, 2006 at 08:40 PM.
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Joined: Jul 2002
Posts: 11,593
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From: Clayton NC
Originally Posted by Gordonm
I don't think so. I am running the TKO 500 with a 3.27 1st gear and a 3.73 rear. 1st gear is a little short but it gets moving in a hurry. With the 1st gear you have in the 600 it should be just right. I would prefer the 1st gear you have but the 600 was not available the time I got my trans.
(most people just post it and go on) 
I've got the same setup and wish the tko600 was available when I bought mine. The 3:55 should have been the gear I put in when I replaced the ring and pinion last year but I stayed with what Gordon has at 3:70. She definately gets up out of the hole but you better be shifting quick in first gear and 2nd and 3rd gear is where the magic happens. A 3:55 would make 1st a little better but 5th would then be only useful above 70mph for me.. With the 3:70 and my cam and engine profile 1st is short, 2nd, 3rd and 4th right on and 5th is good for anything above 55mph.... 
Dave..
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Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Mine actually goes lean to when I get on and then gradually pulls back down. I changed the shooters ( only had 35's ) and bumped the primary jets up to 78 and it still goes lean. I currently have the motor out and am taking it to an engine dyno to have it professionally dyno tuned. 
Thread Starter
Instructor
Joined: Feb 2005
Posts: 188
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From: Kearney Nebraska
Originally Posted by MotorHead
Mine actually goes lean to when I get on and then gradually pulls back down. I changed the shooters ( only had 35's ) and bumped the primary jets up to 78 and it still goes lean. I currently have the motor out and am taking it to an engine dyno to have it professionally dyno tuned.
