Tuning issues.. Jake can you advise?, advance curve or jetting (that is the question) |
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Tuning issues.. Jake can you advise?, advance curve or jetting (that is the question) |
brant |
Jun 9 2009, 12:52 AM
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#1
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914 Wizard Group: Members Posts: 11,641 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
I finally got my latest project running but not well enough
I need to do a little tuning... its a 1.7 motor with a cam (don't know the specs of the cam) from the previous owner I can get leak down/compression, but don't have them at this moment. I also don't know the compression, but it is mild... probably stock the P.O. claims it was rebuilt and I believe it I took all of the tin/push rod tubes off, and it looks to have been rebuilt with out worn/shot stock cam lobes and with lifters showing no significant wear doesn't seem to burn-smoke or leak any oil at this point. Its running 40mm dual webers, currently testing at 3300 foot altitude (motor came from a running car at about 5500 ft) I rebuilt the carbs and the jetting is: -28mm (chokes) main venturis -2ndary venturis 4.5 -main jets 115 -air jets 200 -emulsions F11 -acc. pump ball jet 50 -acc. pump towers 50 -idles 50 I've never carbed a 1.7 before The motor came with a 009 distributor and points I ditched it and put in a L-jet 914 (1.8) distributor with points, blue coil, and no retard/advance lines hooked up the cap/rotor/plugs/wires are all good-new car idles smooth, pulls fine from standing, and then stumbles mildly from 2000 - 3000 the car clears out and runs great at 3000 or 3100rpm timing is currently set at 29degree's, but this is my norm for altitude. dad and I are in disagreement about the cause he thinks its too rich for the tiny motor I think its a distributor curve issue Jake, do you know? I have a Djet distributor available easily... or could put the 009 back on... or think maybe I should buy an 050 somewhere to see if the curve is actually the problem We discussed buying 110 mains also to play with it... thanks in advance for any advice from the guru's out there brant Attached thumbnail(s) |
brant |
Jun 9 2009, 07:24 PM
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914 Wizard Group: Members Posts: 11,641 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
its easy to flood it out at starting and the plugs certainly are not lean looking....
I was thinking it might be too rich for ameasly 1.7 (1/7th less displacement than a 2056?) hmmm I'll buy one set of smaller mains and if that doesn't do anything I can always bore out or increase the jet sizes myself to go richer I'm thinking I may buy an innovate tail pipe fixture too and see what the guage says do other people run the 1.8 ljet distributor with carbs? should I try to hook up the advance side of the dash pot to a vacuum line? Mike, do you have any spare 050 distributors that I could throw into the motor for a 5 minute test run to rule out the timing curve side of the equation? Mike, are you running that mallory yet.. and what distributor did you have in it before the mallory? thanks all brant |
Gint |
Jun 10 2009, 07:22 AM
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#3
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Mike Ginter Group: Admin Posts: 16,083 Joined: 26-December 02 From: Denver CO. Member No.: 20 Region Association: Rocky Mountains |
Mike, do you have any spare 050 distributors that I could throw into the motor for a 5 minute test run to rule out the timing curve side of the equation? Mike, are you running that mallory yet.. and what distributor did you have in it before the mallory? thanks all brant I probably still have an 050 laying around here somewhere, but I'd have to find it. Of course you're welcome to use it if it will help your troubleshooting. Let me know and I'll see if I can dig it up. The Mallory has been installed for a year or so now. Prior to that the zambeziteen had a 009 installed. You can borrow that too if'n you want. (IMG:style_emoticons/default/wink.gif) Hell, I even have a dual point 009 around here somwhere. Don't know who went to the trouble to make that thing up. (IMG:style_emoticons/default/laugh.gif) The problem your having doesn't sound like ignition or advance curve to me, but whaddoIknow... I did find out at C&C last Saturday though that Scott's 40IDF's as well as mine (I was shocked (IMG:style_emoticons/default/blink.gif) ) do in fact have a vacuum nipple! Both of them. I never could see this on a diagram, but it's there bigger than life. Yours might also. If so, you could add vacuum to your dizzy and get the additional benefits of vacuum advance curve to the 1.8 unit. Call me this afternoon anytime after 3:00. (IMG:style_emoticons/default/wavey.gif) |
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