Dat_82_720 Posted May 2, 2012 Report Share Posted May 2, 2012 I recently did the weber swap on my 82 720 Z22 and it is a %1000 improvement over the stock carb. My ONLY problem is that from a dead stop, if you go more than 3/4 throttle it will bog the engine down and cut off. If you are cruising down the road and nail the gas, it will hesitate but not bog down....it will get up and go after about a seconds hesitation. what could cause this? the only adjustment i've done to the carb out of the box was a little idle adjustment Quote Link to comment
poor-mans-720 Posted May 2, 2012 Report Share Posted May 2, 2012 I googled the symptoms, and a boat forum popped up. There was one, in which a SBC had the same issue, members on the forum said it was lean on launch. So you might try and adjust the mixture on it. I dont have a weber, so i dont know which screw it is. But i have adjusted my Hitachi, and it was running pretty crappy after removing all the emissions stuff. But a little adj. and back in business with alot of power back. So on another note... you really like the weber? I mean you think it was worth the what, $350?? I really need to pony up and get one... but just can not see spending that money. Would rather buy another motor and do a swap... VG30 or KA... I need to find a used one... poohy. oh.. pics.. I have an 82 KC and love to see pics of others... oh, welcome to the forum... I used to be stationed in Charleston... Miss it, hate WA... Quote Link to comment
Dat_82_720 Posted May 2, 2012 Author Report Share Posted May 2, 2012 wow, thats the quickest and most informative response ive gotten out of the 4 datsun forums i posted in.....normally it took a day or 2 to even get a response. I think ratsun might be my new home, lol. But anyway, i think i might try adjusting the mixture screw like you suggested. I live in DUrham, NC now but ill be going back to Chas. this weekend. BUt yea, i love it and i got it off ebay for 263 with free shipping, thats what changed my mind about getting one. Ill post another thread with pics of my truck later! gotta go to work now! Quote Link to comment
poor-mans-720 Posted May 2, 2012 Report Share Posted May 2, 2012 haha, yea. Ppl are on this all day long. post pics. Will get you replies even faster. Even if its not the part of the truck that you are talking about. Just post pics of the trucks. I found they keep ratsun members happy. And there is a pretty good group of 720 guys on here. There is a button on the top left, that says "Follow this topic" if ya click on it, it sends ya emails, each time a post is posted... My email goes straight to my phone, so i get real time updates of threads. you can see who follows your thread, and the better it is, the more you'll get... Build it, and they will come.... (but be sure to post pics)... Quote Link to comment
datsunaholic Posted May 2, 2012 Report Share Posted May 2, 2012 This is a common issue with Webers. The secondary is mechanically opened, so when you mash the throttle at idle, it opens. The stock carb did NOT do that. It had a vacuum secondary, which would open at full throttle but only when manifold vacuum was high enough to allow it. Otherwise, it bogs because you have too open a throttle and no vacuum or air velocity, so it goes lean. The carbs are jetted kind of conservative- unless sold by a reputable carb dealer who sets them up for a particular application, they basically are never right for anything specific. So it's possible you need different idle jets to enrichen it so it doesn't get so lean at idle. Now, if the carb wasn't new, or even if it is, perhaps the accelerator pump and nozzle aren't working right. You can check that with the engine off, just look down the carb and cycle the throttle by hand and see if it sqirts a healthy stream down the primary. . Quote Link to comment
poopypants720 Posted May 2, 2012 Report Share Posted May 2, 2012 Its funny to see questions like this constantly pop up on here and 720 world and no one bothers to use the search function cause its def been asked before and likely recently... All the same, welcome to the forums, ratsun is a great resource. Quote Link to comment
datzenmike Posted May 3, 2012 Report Share Posted May 3, 2012 The Weber accelerator pump may also be adjustable. Set it to pump more fuel in and this will mechanically richen up the off idle throttle. Quote Link to comment
poor-mans-720 Posted May 3, 2012 Report Share Posted May 3, 2012 +1 on the search... search several different topics related to your issue. I did not know that this was a topic recently covered... So... Quote Link to comment
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