Greetings to all... Currently working on a 200 ci six cyl engine for 1970 Maverick. The original 1970 Carter YF carb has serious problems but I have a couple of other Carters from larger 6 cyl engines that are excellent condition but not exact replacements. They are: 1) Carter YF from 1976 240 ci six cyl ford 2) Carter RBS from 1970 250 ci six cyl ford I have the necessary carb spacers/adaptors for bolting either of the carbs to the stock intake and the means to make the accelerator linkage work. Both carbs have throttle bores less than the intake bore. Three questions: 1) Is there any reason why either of these carbs wont work? 2) Is either of these carbs much better than the other? 3) Will either of these improve performance compared to the original carb? Thanks for interest and replies.
You said that you have the spacers for the other carbs. Did you see if the spacers actually fit on the manfold? the 200 engine has a differant spacer pattern compared to the 250 and it will not fit on a 200. If by chance you can make them work use the one from the 250. Good luck
mike75mav is correct. My gut feeling is neither carb you have will fit. If I were in your shoes, I think I would ebay the carbs you have and use the money to buy a remanufactured carb for your engine from any auto parts stores. The bore size and stud spaceing of the intake changed several times over the years with the 170/200 engines, and it's hard to say what will fit and what won't without actually just trying it. If you CAN get one of the carbs to fit, I would suggest the Carter RBS. However, your stock air filter housing will not fit. You will need to get one from a 250 Maverick.
Thanks for replies Mike and Jamie... The RBS from the 250 will bolt up to the adapter on the 200 with no problem. I have a mill, lathe, and surface grinder and can make any adapter needed to fit the 240's YF carb to the 200's manifold. Diameter of the intake is 1 3/4 in while the YF's throttle bore is less at 1 21/32 in - the RBS's throttle bore is even smaller. Also can make any adapter needed for air cleaner. Perhaps I need to reword my question a bit. We know that different carbs have different CFM ratings. With this in mind, the question is: 1) Are the CFMs for these carbs close enough where the swap will work? (i.e. will the gas be sucked from the venturi like it should be if placed on the smaller 200 ci six) 2) Has anyone actually tried these swaps? Again, thanks for replies and appreciate the interest...
Hmmmmmm!, sounds like you have some plans , ( and the machines and skills) so go ahead and make your adapter and put the other carb on, run it , and get back to all and let us know how things work out!
Both carbs that you have will work on your 200 Cu in six. You will have to be careful with the idle adjustments and make sure that the accellerator pumps are working at the right time to give you the added fuel you will need to enrich the mixture as the carb opens up. They flow more air than your stock carb and are jetted for larger engines so you may have to get jets one to four sizes larger than the stock jets in the carbs. The carbs are larger but they are not "oversized" for your engine, they have just been set up for engines that draw more air through them which pulls more fuel through the jets. With the proper mods (its easy to do) you will have a carb that give you a bit better performance. Don't go crazy with jet sizes. get the three or four jets and install one and drive it to see if it smooths out your engine. Pull the two center plugs and see if they are getting too much gas - if they do then you have gone too far. The 200 intake manifold is a long "log" type that tends to run rich in the center and lean on the two outer ports. You have to have it rich enough to get fuel to burn at the ends and keep it lean enough that you don't foul plugs at the center.
has anyone ever tried to rejet the orignal carb on a 200 totry and get better gas mileage. myselfandiamhopeless
