450rman Posted April 13, 2015 Report Share Posted April 13, 2015 Weber 32/36 carb is pretty new. Motor just rebuilt. I replaced plugs wires cap n rotor and coils. Idled good before motor was rebuilt. Now it idles rough and spark plugs are covered in black soot. All emissions vacuum lines have been removed beside carb to distributor. Any ideas? Quote Link to comment
datzenmike Posted April 13, 2015 Report Share Posted April 13, 2015 Soot is an indication the carb is running rich Check the choke is fully off when warmed up. If not off... Check that there is power to the choke heater when engine is running. Is your alternator charging???? Choke won't shut off if no charge. Check/clean/lubricate the linkage to free it up Check the float is not sticking or set to the wrong height on carb Is there dirt caught in the needle valve at the carb inlet. Nedle valve not closing the carb will flood. Was carb rebuilt? Primary and secondary jets may have been swapped by mistake. You have stock fuel pump? Must be no more than 3.5 PSI or it will flood an old weber. Quote Link to comment
450rman Posted April 13, 2015 Author Report Share Posted April 13, 2015 I will check that stuff. Im no carb expert. It is stock fuel pump. How do i know what height to set float? Quote Link to comment
datzenmike Posted April 13, 2015 Report Share Posted April 13, 2015 Weber? I have no idea. Try a weber website for float info. I would exhaust the other ideas about the choke first. Quote Link to comment
450rman Posted April 14, 2015 Author Report Share Posted April 14, 2015 I noticed water in the fuel. Would that cause these issues? Choke is working good and so is the float. Quote Link to comment
banzai510(hainz) Posted April 14, 2015 Report Share Posted April 14, 2015 is the gas tank fuel hose in the wheelwell? loose clamp On 521s it is and water can run down the hose inside the tank. get gas dyhydrator Quote Link to comment
450rman Posted April 14, 2015 Author Report Share Posted April 14, 2015 Not sure i will check it out. I dont think the choke is working properly. It doesnt want to idle when its cold. I dont know how to adjust it. Quote Link to comment
ggzilla Posted April 15, 2015 Report Share Posted April 15, 2015 Easy. With engine fully cold, rotate choke until it just closes 100% when you open the throttle slightly. Then tighten it. For easy starts and perfect cold idling, make sure it closes 100% when engine is cold. But also make sure its not any tighter than that or it may not open fully when warm. Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 Ok so fully cold the butterfly should be completely closed? A buddy of mine said it should be open a little bit. Isnt there an idle adjustment? It doesnt idle high when cold. Quote Link to comment
ggzilla Posted April 15, 2015 Report Share Posted April 15, 2015 Your buddy is wrong. Automatic chokes have an automatic choke break which will automatically open the butterfly a little bit as soon as the engine starts. Check any repair manual for the facts. Yes there is s Fast Idle adjustment screw. It should idle 1600-2400 rpm with choke adjusted correctly. Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 Im having a hard time getting it adjusted right(high idle). But when it warms up the flaps are open all the way and its still idling rough and running really rich. Do you know what jets i should be running? Quote Link to comment
ggzilla Posted April 15, 2015 Report Share Posted April 15, 2015 The idle speed and idle mixture must be adjusted. Even if the wrong jets are in there it should idle OK. Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 Hmmm. Im baffled then. Dont know where else to look. What else could be causing it to run so rich at idle? It leaves a puddle under the tailpipe. Quote Link to comment
ggzilla Posted April 15, 2015 Report Share Posted April 15, 2015 It may be caused by incorrectly adjusted carb. Float level too high, or mixture screw out too far are likely causes of those symptoms. Or something unusual could be wrong. If you screw the idle mixture screw in all the way, does the engine die? Quote Link to comment
datzenmike Posted April 15, 2015 Report Share Posted April 15, 2015 Hmmm. Im baffled then. Dont know where else to look. What else could be causing it to run so rich at idle? It leaves a puddle under the tailpipe. Already answered... Soot is an indication the carb is running rich Check the choke is fully off when warmed up. If not off... Check that there is power to the choke heater when engine is running. Is your alternator charging???? Choke won't shut off if no charge. Check/clean/lubricate the linkage to free it up Check the float is not sticking or set to the wrong height on carb Is there dirt caught in the needle valve at the carb inlet. Nedle valve not closing the carb will flood. Was carb rebuilt? Primary and secondary jets may have been swapped by mistake. You have stock fuel pump? Must be no more than 3.5 PSI or it will flood an old weber. Drips from the tail pipe is just normal condensation. All vehicles will do it. Idle fuel is unaffected by jet size. Idle has it's own fuel supply. The '85 has no idle mixture adjustment as it is set and sealed at the factory. So do the following... Be sure that the valve lash has been checked and set and that the ignition has been checked and set. Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 Its not just drips. Its a big wet spot that leaves a big spot of carbon on the ground. One thing i didnt check is the needle valve at the inlet. I also know nothing about what jets should be where or what size they should be. If the timing was off by 1 tooth would it cause this? Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 It has one of those cheap dial type fuel regulators on it. I have it set on 3. Ive heard that those arent very reliable but i put it on 2 and drove it and it started cutting out. Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 No the engine doesnt die when i turn the mixture screw all the way in. Thats actually where it idles the best. Quote Link to comment
ggzilla Posted April 15, 2015 Report Share Posted April 15, 2015 Measure the fuel pressure instead of guessing. The Idle is unaffected by jet size. Idle has its own fuel supply. The timing cannot cause a fuel puddle. Has you carb been recently opened? Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 I dont think the carb has been opened up. The motor was just rebuilt but i dont think they messed with the carb. The carb is only a year old. Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 Do i need to put a inline guage to measure fuel pressure? Quote Link to comment
ggzilla Posted April 15, 2015 Report Share Posted April 15, 2015 Do you have a vacuum gauge? Those measure fuel pressure. Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 No i dont. I can get one tho. The only info i found on making sure the float was set at right height was really confusing. It said the float should be sitting level and should have 2mm of movement when you push down on it. Mine had way more than 2mm. Quote Link to comment
ggzilla Posted April 15, 2015 Report Share Posted April 15, 2015 Yes, hanging level when upside down. Most troubleshooting vacuum gauges can check fuel pressure too. Borrow one or buy one (about $25 at Sears). $15 at Amazon or Harbour Freight. Quote Link to comment
450rman Posted April 15, 2015 Author Report Share Posted April 15, 2015 What is that measurement? 11/16? Quote Link to comment
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