scotster9822 1 Report post Posted February 28, 2015 Hi, I purchased a 1969 mustang grande with the 250 inline 6 motor. everytime I start it the carb catches on fire, the firing order is in the right postion and i have adjusted the timing of the distributor in every way imaginable to try and get it to stop. The Valves were done and adjusted and the head was surfaced there where no cracks in it. The headgasket was also changed when this was done and the Carb was also rebuilt. any suggestions? Thank You in advance 1 Ronaldbaf reacted to this Quote Share this post Link to post Share on other sites
69RavenConv 286 Report post Posted March 1, 2015 I've seen this when the ignition timing is way off. Or possibly an intake valve that isn't closing properly. I know you said you checked both of these things but may be worth another look. I would think the only way a carb can catch on fire is combustion coming back up the intake manifold or a gasoline leak dripping on a hot surface. 1 Protowrxs reacted to this Quote Share this post Link to post Share on other sites
Max Power 74 Report post Posted March 2, 2015 You mentioned that the valves were done and adjusted and the head had been surfaced. If I remember correctly, the small block L6 used a rocker arm shaft and non-adjuctable rockers. If you milled a decent portion of the head, you would have to go to custom length pushrods to get the valves to close properly, depending how much you took off. Seems a longshot with the range that should ba allowed with hydraulic lifters, but it is a thought. Other than that I am not sure what else we have to go on. Quote Share this post Link to post Share on other sites
barnett468 418 Report post Posted March 3, 2015 . does it start? does it run ok? can you drive it? what is your timing set to? Quote Share this post Link to post Share on other sites
scotster9822 1 Report post Posted April 2, 2015 fixed that problem turned out the the distributor gear was put in in the wrong position Thank you everyone for the help Quote Share this post Link to post Share on other sites
SA69mach 39 Report post Posted April 2, 2015 Glad you got that fixed. Kinda takes the fun out of a drive ! Can you expand a little on the problem and the fix.? Was the gear too high or low on the shat? Incorrectly pinned? Or was the Distributor installed 180 degrees out of position? I was expecting the 180 degree off, as the problem. Causes massive backfires, especially in the six cylinders. Quote Share this post Link to post Share on other sites
klevor 10 Report post Posted April 2, 2015 Firing order backwards will make it do that for sure. Quote Share this post Link to post Share on other sites
scotster9822 1 Report post Posted April 4, 2015 the distributor gear was in 180 degrees off now I'm running into a new problem runs great at idle but falls on it butt and stalls when you accelerate. If i baby it and put the choke on 3/4 i can get the car to rev. I just found out by trying to buy a rebuild kit that the carb that is on it is from a 1965 2.8L mustang and mine is a 1969 250ci 4.1L Does anyone know what carb is supposed to go on it? even after rebuilding the carb that is on it, it runs to lean I need a carb that will suck the proper amount of gas. My brothers 1971 Mavrick only has the 200ci motor and his carb is twice the size of mine. Quote Share this post Link to post Share on other sites
SA69mach 39 Report post Posted April 4, 2015 Don't know if you have looked at this site, but it has a lot of information, tech tips and troubleshooting info that may help you decide. Assuming fuel pump and fuel pressure is good, it seems you have too little carburetor for that engine. Swapping to a 2V carb is a common upgrade. http://classicinlines.com/logmods.asp Quote Share this post Link to post Share on other sites
SA69mach 39 Report post Posted April 4, 2015 sorry, this is the best page to identify the carb you have now, and the stock carb for your engine. http://classicinlines.com/CarbChoice.asp Might be suitable for your needs to just get the correct sized 1V carb. It will avoid modifying the intake for a 2V adapter. Can you identify whether you have a Load-o-Matic distributor? That will matter. The carburetors and Distributors are kind of matched. Reading a bit, it seems the trend is to dump the Load-o-Matic and get a Duraspark and a matching 325 cfm 1V, as a minimum fix. Better distributor and correctly sized flow for your 250ci engine. One thing you want to consider also, is that the stumble you have can be caused by too much fuel. if your carb is not performing properly it can flood the intake with too much fuel. It is actually more likely to be very rich or flooded when you have a bog off idle. Even if you have the idle mixture well tuned and a nice idle, the jetting is what takes over when throttle is applied, and if that is way too rich you get a bog immediately off idle and a stall. if it is rich but not stupid rich it will bog and then run properly in the higher rev range. Without seeing a pic and maybe some numbers off that carb I cant guess at how to adjust the jetting. it would be nice to at least get that carb running well enough to drive the car. It is likely the installer over jetted it in an attempt to "match" the cfm of the correct sized carburetor. That is a mistake. Quote Share this post Link to post Share on other sites
1969_Mach1 333 Report post Posted April 4, 2015 We know its the wrong carb. But disregarding that, it sounds like the accelerator pump is not working. For the cost of a rebuilt kit, float, and cleaner, it might be worth trying to rebuild it the funds are not there for the correct carb. Now, aerosol cans of carb cleaner are not the best or correct way to clean a carb when rebuilding. But sometimes, that's all that can be done. If you have to go the aerosol can route to clean it, get several cans. Quote Share this post Link to post Share on other sites
scotster9822 1 Report post Posted April 5, 2015 thank You Guys, I did try and rebuild the carb and the accelerator pump was replaced and it had the same issue. I will check the chart right now to see what carb it needs but has anyone ever put the taller carter yf carb on it? I got 1 from my brother who had it on his 71 maverick the car runs great with it on but the clip on throttle linkage is to short and will not connect also it looks like the air filter assy will barley clear when closing the hood I haven't tried putting the air filter on yet because I want to figure out the throttle linkage part first. also how do you tell which distributor I have, Mine does not have the vacuum advance on the distributor. Thank You again for all your help I can't wait to get her running great! HAPPY EASTER! Quote Share this post Link to post Share on other sites
SA69mach 39 Report post Posted April 5, 2015 I am no expert on the inline six carbs and distributors, by any measure. I suggest you read all of this; http://classicinlines.com/Loadomatic.asp and then post some pictures of your carburetor and your distributor. You always get more responses and information with pictures. Seems like the load o matic distributor should have a vacuum line attached, for sure. It relies on vacuum alone to advance the spark. There is no mechanical advance on the LOM distributor, which is one of the big problems with it. Lets identify what you have first, and take it from there. Quote Share this post Link to post Share on other sites
1969_Mach1 333 Report post Posted April 5, 2015 I would double check and make certain the accelerator pump works correctly. With the engine off and the choke plate open, open the throttle while looking down the top of the carb. You should see a steady stream of fuel spray out from the accelerator pump nozzle. Other than that, I have rebuild carbs where soaking in carb cleaner was not enough to clean out passages and I had to use wire or small drill bits by hand (not on a drill) to clear out passages. Sometimes when finding the source of a problem you have to keep checking to make certain things are correct, tune up, ignition timing, etc. and eventually you come across something that is not. Quote Share this post Link to post Share on other sites
SA69mach 39 Report post Posted April 5, 2015 +1 Check visually to confirm the accelerator pump operation. Quote Share this post Link to post Share on other sites
scotster9822 1 Report post Posted April 6, 2015 Here are some pictures of the distributor and both carbs Quote Share this post Link to post Share on other sites
scotster9822 1 Report post Posted April 7, 2015 I am looking at buying the autolite c844 carb from autozone they have 20%off ship to home orders right now and its only $219.99 has anyone ever used one of these carbs? Quote Share this post Link to post Share on other sites
scotster9822 1 Report post Posted April 30, 2015 Just wanted to let everyone know this carb worked great and I found it at rockauto.com cheap Quote Share this post Link to post Share on other sites
