mineurbiz Posted February 19, 2009 Share Posted February 19, 2009 Tore apart the carb, cleaned it and replaced all the orings but still will only run with the choke on. I tried upping the idle but this did not help. I am thinking a bigger jet? Quote Link to comment Share on other sites More sharing options...
RUn2it Posted February 19, 2009 Share Posted February 19, 2009 (edited) Tore apart the carb, cleaned it and replaced all the orings but still will only run with the choke on. I tried upping the idle but this did not help. I am thinking a bigger jet? I'm guessing it has been sitting awhile. Sitting for awhile doesn't cause a need for a bigger jet but will clog with the residue left from evaporated gasoline. Use carb/brake clean, no metal wire etc. You can take a bristle from a broom, paint,solvent tank brush to help. Look through the jet toward a light (backlight it). If the choke is a butterfly plate type, those increase manifold vacuum and vacuum is is what "pulls" the fuel into the engine so if the pilot jet is clean you might have a vacuum leak. The leak would be anywhere between the carb slide and cylinder. If the choke is the plunger type like on most atvs it's a bypass circuit that adds fuel where the butterfly type increases vacuum to pull more fuel. Try with the choke off but block the carb intake partly, if it runs the pilot jet is supplying some fuel at least. This is for any typical carb, and should help you narrow it down. Post back the results Oh yeah, there's a low speed air screw probably on the left side near the intake end of the carb, but this meters air. The screw at/near the slide is the slide stop (idle speed) You may know all this but just in case you didn't is the reason for the detail. good luck and you have about a week before the Regatta Edited February 19, 2009 by RUn2it Quote Link to comment Share on other sites More sharing options...
mineurbiz Posted February 19, 2009 Author Share Posted February 19, 2009 (edited) I'm guessing it has been sitting awhile. Sitting for awhile doesn't cause a need for a bigger jet but will clog with the residue left from evaporated gasoline. Use carb/brake clean, no metal wire etc. You can take a bristle from a broom, paint,solvent tank brush to help. Look through the jet toward a light (backlight it). If the choke is a butterfly plate type, those increase manifold vacuum and vacuum is is what "pulls" the fuel into the engine so if the pilot jet is clean you might have a vacuum leak. The leak would be anywhere between the carb slide and cylinder. If the choke is the plunger type like on most atvs it's a bypass circuit that adds fuel where the butterfly type increases vacuum to pull more fuel. Try with the choke off but block the carb intake partly, if it runs the pilot jet is supplying some fuel at least. This is for any typical carb, and should help you narrow it down. Post back the results Oh yeah, there's a low speed air screw probably on the left side near the intake end of the carb, but this meters air. The screw at/near the slide is the slide stop (idle speed) You may know all this but just in case you didn't is the reason for the detail. good luck and you have about a week before the Regatta I tore the whole carb down and replaced all the oring, replaced the jets and scrubed everything down with carb cleaner and a tooth brush, this got it to start. I also removed the manafold and cleaned it and used threebond 1211 to seal it both motor side and carb side of the manifold. I found the gaskets last night, so I can clean off the 1211 if needed and put them in but seems like the 1211 should seal it. I also tried to up the idle with the choke on then turn it off and it runs for a second then dies. I thought about trying the low speed air screw but have not yet. I will give you suggestion of blocking part of the intake off tonight. The goofy little thing actually runs really well for 26 years old with the choke on, runs like it should with the choke off lol Edited February 19, 2009 by mineurbiz Quote Link to comment Share on other sites More sharing options...
dunefreak Posted February 19, 2009 Share Posted February 19, 2009 check the gasket/ seal on the intake manifold tube for air leaks. Spray some carb cleaner on it while its running and see if it dies or rpm picks up. Quote Link to comment Share on other sites More sharing options...
mineurbiz Posted February 19, 2009 Author Share Posted February 19, 2009 I will try the carb spray, I did seal them both fresh last night but I could have done something wrong, thanks for the tip Pete. Cool thing is that it runs good with the choke on atleast and fires up fast, so even if I don't get it fixed in time, it will still run and be there. I appreciate all the tips guys, keep them coming, I would rather go home with a list then one at a time, so I appreciate it. Quote Link to comment Share on other sites More sharing options...
RUn2it Posted February 20, 2009 Share Posted February 20, 2009 I will try the carb spray, I did seal them both fresh last night but I could have done something wrong, thanks for the tip Pete. Cool thing is that it runs good with the choke on atleast and fires up fast, so even if I don't get it fixed in time, it will still run and be there. I appreciate all the tips guys, keep them coming, I would rather go home with a list then one at a time, so I appreciate it. Thought of something else. take the carb off, remove float bowl screws, attach the fuel line to the carb with the bowl in place, no screws, turn on the fuel, wait long enough to fill, holding carb still and level, turn off fuel, and carefully lower the float bowl and see how much fuel is in it. Maybe float setting is too low and the choke pickup is either lower or ported to the fuel inlet circuit. Just a thought, it's not electrical or air problem so it's narrowed down to just a few possibilities. Quote Link to comment Share on other sites More sharing options...
dunefreak Posted February 20, 2009 Share Posted February 20, 2009 just wanna make sure, you know choke is UP right? Quote Link to comment Share on other sites More sharing options...
mineurbiz Posted February 20, 2009 Author Share Posted February 20, 2009 just wanna make sure, you know choke is UP right? lol yeah even verified when i had the carb off that the butterfly was open when up. Quote Link to comment Share on other sites More sharing options...
RUn2it Posted February 20, 2009 Share Posted February 20, 2009 lol yeah even verified when i had the carb off that the butterfly was open when up. It's a butterfly type choke? And you say it's open when up? open = up?????? Quote Link to comment Share on other sites More sharing options...
mineurbiz Posted February 20, 2009 Author Share Posted February 20, 2009 It's a butterfly type choke? And you say it's open when up? open = up?????? Yes sir I tried the carb spray on the manifold but it did not change the idle at all. Spent the remaining time working on my other tank so I can take the POS one off and use this other one for the trip. Quote Link to comment Share on other sites More sharing options...
Foxysandchick Posted February 20, 2009 Share Posted February 20, 2009 Just curious...what size jet are you running? Mine runs fine, but we have a few jets to try out and see what works best, we took the air box off and put on a k&n, so might change the jet next time out. Quote Link to comment Share on other sites More sharing options...
RUn2it Posted February 20, 2009 Share Posted February 20, 2009 (edited) I have question for you biz, if you're into the throttle about 1/3 to 1/2 and shut the choke will it die? And did you check the fuel level in the bowl? It's hard trying to troubleshoot something that you can't see. Could be something in the internal passage for idle air or fuel. I just noticed in an earlier post you said you "replaced the jets", so they're not the ones that were in it when the problem started? Edited February 21, 2009 by RUn2it Quote Link to comment Share on other sites More sharing options...
OGP Posted February 21, 2009 Share Posted February 21, 2009 lol yeah even verified when i had the carb off that the butterfly was open when up. if the butterfly is open when up, Doesnt that mean the choke is off? I thought when the butterfly is blocking off the air the choke is on allowing more fuel. Quote Link to comment Share on other sites More sharing options...
SAND~~SNAKE Posted February 21, 2009 Share Posted February 21, 2009 I have question for you biz, if you're into the throttle about 1/3 to 1/2 and shut the choke will it die? And did you check the fuel level in the bowl? It's hard trying to troubleshoot something that you can't see. Could be something in the internal passage for idle air or fuel. I just noticed in an earlier post you said you "replaced the jets", so they're not the ones that were in it when the problem started? I rebuit my carb and the kit came w/ a 58 size jet and it ran very lean, the jet that came out of it was a 60 and after putting the new air filter on it it also was running lean. Do you know what jet size you put into it? Quote Link to comment Share on other sites More sharing options...
mineurbiz Posted February 21, 2009 Author Share Posted February 21, 2009 if the butterfly is open when up, Doesnt that mean the choke is off? I thought when the butterfly is blocking off the air the choke is on allowing more fuel. am I being a tard? Quote Link to comment Share on other sites More sharing options...
fooshizn1x Posted February 21, 2009 Share Posted February 21, 2009 I'm not familiar with the 70's but check for air leaks. I know its mostly a 2 stroke thing but if you are getting air that is unmetered (anywhere other than from the intake) you can have a problem like this. good luck. see ya in the dunes Quote Link to comment Share on other sites More sharing options...
nightime Posted February 21, 2009 Share Posted February 21, 2009 (edited) fuel tank petcock is on...or something blocking the flow?? sand in the tank or the fuel filter. cracked fuel line. good luck Edited February 21, 2009 by nightime Quote Link to comment Share on other sites More sharing options...
RUn2it Posted February 21, 2009 Share Posted February 21, 2009 if the butterfly is open when up, Doesnt that mean the choke is off? I thought when the butterfly is blocking off the air the choke is on allowing more fuel. Thanks OGP, welcome to the club, there's 2 members now. OK, mineurbiz, 1 more time then I'm gone. On second thought no need to type the same stuff again, if you want to, post back with results. good luck Quote Link to comment Share on other sites More sharing options...
RUn2it Posted February 21, 2009 Share Posted February 21, 2009 I rebuit my carb and the kit came w/ a 58 size jet and it ran very lean, the jet that came out of it was a 60 and after putting the new air filter on it it also was running lean. Do you know what jet size you put into it? Sorry, was distracted. put the 60 back in (maybe bigger) and if you're running a less restrictive air filter than prior raise the needle a notch (lower clip on needle). With all the additives in fuel now it's hard to get a good plug reading but what's the worse thing that can happen if you're running too rich? Foul the plug. What's the worse that can happen if you're too lean? Maybe piston siezure or burn o hole in the crown. I'll take the fouled plug. Quote Link to comment Share on other sites More sharing options...
dunefreak Posted February 21, 2009 Share Posted February 21, 2009 let me clear up the choke confusion Mark lol choke on = lever up = plate closed (allows for a richer mixture) choke off = lever down = plate open In this pic the choke is OFF Quote Link to comment Share on other sites More sharing options...
SAND~~SNAKE Posted February 21, 2009 Share Posted February 21, 2009 Sorry, was distracted. put the 60 back in (maybe bigger) and if you're running a less restrictive air filter than prior raise the needle a notch (lower clip on needle). With all the additives in fuel now it's hard to get a good plug reading but what's the worse thing that can happen if you're running too rich? Foul the plug. What's the worse that can happen if you're too lean? Maybe piston siezure or burn o hole in the crown. I'll take the fouled plug. Thanks, we are going to try 60 then 62 and 65 if needed next trip out . Anybody else know what jet size you are running?? Quote Link to comment Share on other sites More sharing options...
mineurbiz Posted February 21, 2009 Author Share Posted February 21, 2009 OK sorry guys yes back to the original problem, I pulled the carb off and yes choke is on when up and it only runs in the up position. I also just tried to run it with my figers blocking half the about 3/4 of the intake and still would not run with the choke off. I left the choke on and tried to ride it and it just dies, pulled the petcock (Pete's favorite word) off and it would pass fuel. I am going to put the previous jet back in and try it again (before rebuild) and try it again, but I know I had this same problem before I ever changed it. I will post the results, sorry for the delay, wife got back in town and wanted to spend time together. Quote Link to comment Share on other sites More sharing options...
Foxysandchick Posted February 21, 2009 Share Posted February 21, 2009 am I being a tard? aren't you always? you are a computer nerd, can't expect you to be a mechanic also! Quote Link to comment Share on other sites More sharing options...
mineurbiz Posted February 21, 2009 Author Share Posted February 21, 2009 (edited) aren't you always? you are a computer nerd, can't expect you to be a mechanic also! And where are you all day? I got you a job fool so bow down and pay respect lol Besides you better just make the day trip and bring your new little toy. Well took the carb apart for the 3rd time and cleaned it all again, also found that the pilot get was clogged. I had another one in my rebuild kit but it is a threaded one and the original was a press in. I did a little redneck engineering and made it work. Took it down the street and it ran like S&@T, reached down and turned the choke off and it actually ran and ran GREAT with the choke off. Thanks for all those that helped, it is greatly appreciated (accept for Kristin). Oh also got a new pair of shoes for the old girl And the old tank and the replacement (to be repainted later) :angry2: :angry2: Edited February 21, 2009 by mineurbiz Quote Link to comment Share on other sites More sharing options...
RUn2it Posted February 22, 2009 Share Posted February 22, 2009 And where are you all day? I got you a job fool so bow down and pay respect lol Besides you better just make the day trip and bring your new little toy. Well took the carb apart for the 3rd time and cleaned it all again, also found that the pilot get was clogged. I had another one in my rebuild kit but it is a threaded one and the original was a press in. I did a little redneck engineering and made it work. Took it down the street and it ran like S&@T, reached down and turned the choke off and it actually ran and ran GREAT with the choke off. Thanks for all those that helped, it is greatly appreciated (accept for Kristin). :angry2: :angry2: The pilot jet was clogged, that was the 1 suspect. It's not rocket science, it's the same for LT 500 or 70, but you had me going with the choke thing Glad you got it running good. Quote Link to comment Share on other sites More sharing options...
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