PDA

View Full Version : JD spitfire help!!



hondahaulic
03-13-2007, 09:47 PM
Hey, I've been doin a little work to an old john deere spitfire and the fuel lines have been confusing me a little bit. Theres one line that goes from the right side of the tank over to a small metal box on the left side. Then there are 2 more lines comin out of the little metal box. One of them goes to the carb, and the other one goes to the bottom-end on the left side of the motor.

There are atleast 2 gallons of premix in the tank, but when you try to get it running it acts like its out of gas. If I fill the line that goes to the carb with premix, the motor will run great until it burns off the gas in the line. This has me stumped and im curious as to what the line going to the bottom-end does (maybe it helps draw the fuel from the tank to the carb or something???).

The snowmobile has a bad track so i have been pondering the idea of puttin the motor in a trike frame. If I did this, could I just run a line from the trikes tank to the carb so its gravity feed? (and then plug the line going to the bottom of the motor).

Thanks alot for any help and hopefully this isnt too confusing.

85hondaatc125m
03-13-2007, 10:24 PM
I think that line leading to the engine is a vacum line, the compression from your engine creates suction, and that makes your pump work(the little metal box). If you have an air-compreesor with a blower end on it, take the gas cap off of the gas tank, put the blower end of the air compressor in the tank about 2 inches, cover the rest of the gas tank lid with a rag and get someone to pull on the pull start, and that should blow gas to your carbs and get it running.

hondahaulic
03-13-2007, 10:33 PM
hey thanks for the idea i'll be sure to give that a try, it seems like that should work. on a side note, does anybody know about what this thing should have for horsepower? its just an air cooled single carb twin, and im pretty sure its a 340cc.

84honda200s
03-14-2007, 12:39 AM
its still a fast engine though. i like them old engines. your problem almost sounds like a bad fuel pump. i would just either rebuild the pump or get a different pump. hell if you need a new one let me know. i have 2 pumps here for single carbd engines. one of em was rebuilt last year. well none the less try to take a lawn mower fuel tank keep it in the air with premix gas in it and gravity feed it. if it runs like that it is the fuel pump.

85hondaatc125m
03-14-2007, 12:55 AM
My friend got an old polaris sled, and he had the same problem as you, the gas just wouldnt pump and get gas to the engine, i told him to try that thing with the air compressor and it work, but if that doesnt work, you might have to get a new pump for 84honda200s there

Big D
03-14-2007, 09:38 PM
Put a priming bulb from an outboard motor in the fuel line. Prim it till you have fuel at the carb then start it and keep squeezing it to keep it running. You might get lucky and the pump will work on its own. Before you do this I would make sure that all the lines are in good shape and that you don’t have an obstruction in the tank or lines.

hondahaulic
03-14-2007, 10:46 PM
hey, im pretty sure my problem is the pump because the motor will run if I gravity feed fuel to it. Me and a buddy have pretty much decided to put this motor and its clutches in a trike frame with a gravity feed system so i dont think ill be needing a new pump (but thanks for the offer 84honda200s). I thought about getting it going and just keeping it as a sled, but the track is completely ruined and ive already got an 03 arctic cat zl550. On the other hand, there is a cable sticking out of the top of my carb that someone cut off. Im not sure if its for a choke or what, but its not the throttle cable. Anybody know what this is?

Oh and about puttin the motor in a trike, I think were gonna put it in a 225dx frame, mainly coz thats the only frame i have and sport trikes are pretty rare around here, especially a cheap roller. I've already got most of it planned out on how to get it all to work. I plan on having the jackshaft double as a swingarm bolt, so there will be bearings for the jackshaft on each side of the frame and also a set of bearings for the front of the extended swinger that I plan to make. Ill put a small sprocket on the jackshaft and run a chain back to a chain drive rear end that ill have to get from another trike (no more shaft drive).I'm guessin i'm gonna hafta chop up the frame and extend it about 2" to make room for the motor but it doesn't look like thats gonna be too hard to do. Theres sort of a "bulge" on the left side of the frame to make room for the shaft drive, and I'm definately gonna cut that out and rebuild it narrower so theres room for the secondary clutch. I guess some of this should probably be in the trike forum, but i'll probably wait and post a thread there once i get a little further into the project. oh and sorry for rambling on lol.

84honda200s
03-14-2007, 11:06 PM
sounds like a plan. i wish i could gravity feed my engine that im putting in my go-kart. well anyways good luck man keep us posted.

hondahaulic
03-14-2007, 11:28 PM
yea i bet that go-kart flys after your done. I think i read somewhere that your using a l/c 440.... lol thats gonna be a pretty sweet power to weight ratio. anyway after friday me and a buddy are gonna have 10 days with no school for spring vacation so were planin to get quite a bit done. anybody have any ideas on how much longer i need to make the swinger than the stock one? I wanna have plenty of torque to pick up the front end but i still wanna be able to take off wide open leaning forward withought having to let off the gas. And ill probably gear it a little faster than the stock snowmobile, to make up for the weight and drag difference. yea this is the wrong forum i know i know lol... i'll start a thread in trikesylvania once we make some progress and get some pics.

hondahaulic
03-20-2007, 03:33 PM
hey so is the 2nd cable coming out of the top of my carb the choke? Its not the throttle cable. If its the choke does anybody know where i can get a new cable? This is for the single carb on a 340 kohler from a 78 spitfire.

84honda200s
03-20-2007, 11:34 PM
yup it be a choke cable. you can get a universal cable from dennis kirk or just not use one.