Starting my engine on a stand, issues arose |
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Starting my engine on a stand, issues arose |
malcolm2 |
Sep 29 2020, 06:16 AM
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#41
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
I have built a fresh 2.0 and borrowed a set of weber 40s to get her running, broken-in etc....
I bought a new single vacuum distributor with the flame thrower 3 module inside. Also bought the Petronix coil. I built up oil pressure, then connected the gas lines, fuel pump, and coil. Tach and timing light too. After a few tries, she started. As expected running very ruff. Back-firing thru the carbs. I loosened the distributor and tried to make some adjustments. That seemed to help the back-firing a bit, but not totally. I got the idle timing to what looks like 7 btdc, but it is tuff to work everything without a helper. I know next to nothing about these carbs, and about the same amount to tune them enough to bench run the engine, but I am looking into that. Any help would be appreciated on the carbs. I got it idling, again, very ruff. So I wanted to do the cam break in, so I rev'd it up to about 3000 and held there. Maybe a minute and the revs dropped and I had to putz with the accelerator to keep her going. Again up to 3000, same thing revs dropped. I have a note in to my distributor vendor about how this "rev limiter" on this module works. So three things here. She is still running ruff, back-firing etc...and there is the high rev cut-off. Lastly the carbs, any quick checks or adjustments there? Any thoughts or suggestions? |
VaccaRabite |
Sep 29 2020, 06:58 AM
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#42
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En Garde! Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
First off:
(IMG:style_emoticons/default/thisthreadisworthlesswithoutpics.gif) We need pic of your engine on the run in stand! For the back firing you need to adjust the carbs and make sure they are drawing equal amounts of air. You need a tool to do this. Search for a carb snail. Its a gauge that you stick into the throat and it measures airflow. You want the airflow balanced between all the carbs. You also want to be able to hold the engine at 2K rpm for 20 minutes to do the cam break in. And then 3K RPM to set ignition timing. For your run in stand - I put a cheap-o tach on mine, and also rigged a way to work the throttle. A tach is just 1 wire from the dizzy. And the throttle is also really easy. I just put some wire on the carb linkage, pull it to open the throttle to the RPM I want and clamped it off with a pair of vise-grips. field expedient and makes a lot of the tuning easier when you are working solo. Zach |
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