QuestionHi. My name is Chase and I am building a go-kart from scratch and I am using an old riding lawnmower for parts. Everything works on it and I started building a frame for the kart when I ran into a problem.
I need the lawnmower transmission that I am using to extend out about another 8 inches on each side. Is there a way I can make axle extenders of some sort?
Also, I replaced all of the gaskets on this engine, changed the oil and it will not start. However, it also did not start before I did this. I got the mower from a friend and it was sitting in his garage for a long time. The engine is not getting gas but the carburetor is. I can push the release valve on the bowl of the carburetor and gas comes pouring out, but when I look at the inside of the carburetor, I see no trace of gas. Can you help me?
John: You can manufacture you axle extensions with a couple of carrier bearings and some steel round stock. Making the connections for the transaxle and the wheels will be the hardest part of this endeavor.
Remove and disassemble the carburetor. Soak the carburetor overnight in gunk carburetor cleaner and then blow out the passages with compressed air. Install a new kit. When an engine sits for long periods of time the gas turns to varnish and restricts or blocks the gas flow through the jets inside the carburetor. Send me all the model numbers off the engine, please. With these numbers, I can locate a breakdown/IPL for you to view online and for reference if you require more assistance.
Chase: I have already cleaned it and put a new gasket kit/rebuild kit for the carburetor but it still doesn't work I'm not sure what the clutch and choke settings should be at (closed open half) and I'm not sure how far each adjustment screw should be in it?
John: If you did not soak the carburetor, it is most likely not clean. If it set for a long time, the gas turned to varnish and the jets are still clogged. Spray cleaning will not work. The settings of the air/gas mixture screws are: both turn into seat. **do not jam snug only**. Turn both air mixture screws out 1 1/2 turns. Start engine. With throttle at full, set the high mixture screw for proper operation. Use your hand and manually move the governor arm to increase engine speed to set the high air mixture screw or when you put the engine under a load (cutting heavy grass). You may have to adjust the screw in. Once the high mixture screw is set, set the low air mixture screw so there is no hesitation when going from idle to full throttle. Then set the idle if required. You can view a breakdown/IPL of the engine at this address http://www.outdoordistributors.com Click the T. Then select Tecumseh. Then select "do not have part numbers". Enter the model number vm80. Select your model engine. This will download a breakdown/IPL of the engine for you to view online.
Chase: I have another question. My front tires were flat so I took of one of them off the rim and then put it back on. I tried to fill it using an air compressor but it did not work. The one that I didn't take off of the rim did fill up. It has been a couple of weeks since I took it off. It doesn't appear to be stretched in any place at all. It doesn't have a hole in the tire. Is there a mechanism or somthing that I can use to clog the sides so I am sure no air can get out?
John: If you are trying to inflate the tire and the gap between the tire and rim is too large for the tire to seat to the rim, then take a small rope and make a strap wrench. Put the rope in the center of the tire tread and tighten the rope. It will force the sidewalls out and connect with the rim until the tire will seal to the rim. Loosen the rope as you inflate the tire. If the tire is leaking air between the rim and tire over a few hours or days, then run a bead of silicone around the seat of the tire. Inflate the tire and then remove the excess silicone. The silicone seals the small pits that may be in the rim or the tire.
Chase: For the tire I put some fix-a-flat in it, then pumped it up with the air compressor. I soaked the carb one more time and found some dirt cloggong a hole. I need a new gasket set for the carb. The one I got was no good. So if you could help me on that and when I put the trans in first it was moving fine then in second same then in third same but I was in third for a bout 3 min when it stopped so I started it up again put it in first and it will move evry time the engine revs but it makes the sound like I am grinding the gears evern though I'm not. The engine dies if I don't slowly move it to full throttle over a period of 10 min. If I move it straight there it dies.
John: Good the tire is fixed. Now for the carburetor. You can purchase a rebuild kit from your local small engine parts supplier. Once the carburetor has been cleaned and rebuilt, you may not have the revving problem. If you do, then you need to turn the high air mixture screw out 1/4 turn. Send me the model numbers off of the tractor, please. With these numbers I can locate a breakdown/IPL of the tractor and better assist you.
Chase: I already have the breakedoen IPL but I still need an answer for may trans. How tight should I have my head gasket on?
John: I need the model numbers so I can see the equipment in question. Remove the transaxle drive belt from the transaxle pulley. Turn the pulley by hand. Can you feel any grinding or binding? The pulley should rotate smoothly. If not, then the problem is most likely inside the transaxle. The model numbers will assist me in giving a better opinion.
Chase: Hey my transaxles model number is 642 - manufacturer is Peerless. How tight should my head gasket be?
John: The torque for the head bolts is 40ft pds. Remove the belt from the transaxle drive pulley. Turn the transaxle drive pulley by hand. Does the pulley turn smoothly of can you feel a binding? You can view a breakdown/IPL of this transaxle at this addy http://www.outdoordistributors.com/ and click P. Select Peerless. Select "don't have part numbers". Select the series 600. Select 600-648 file to download. If all the idler pulleys are in good shape and are not causing the grinding, then you will have to remove and disassemble the transaxle and locate the bad bearing/gear that is bad. Be sure that the pulley on the engine is in 1 piece and has not worn into 2 pieces.
Chase: I fixed that but now when I start it and I try to move the clutch to full or the throttle to full, I shut down the engine.
John: Check the safety switches. open the high air mixture screw 1/4 turn. If the engine is starving for gas the air mixture screws may be out of adjustment. Set both air mixture screws 1 1/2 turn out from seat. Then run engine at full throttle and adjust the high air mixture so the engine runs smoothly and doesn't bog down under a load. Then set the low air mixture screw so there is no hesitation when throttling from idle to high. Then set the idle.
Chase: Which screw is the high mixture screw and which is the low? when I get it started it usually takes a while and I leave it running on the throttle and clutch I left it on for about 2 min it shtts off like there is not enough gas getting to it fast enough.
John: If the carburetor has a high mixture screw it is usually located in the bottom of the bowl. It has a spring around the screw and goes up into the middle of the carburetor bowl. The low air mixture screw is on the side of the carburetor near the idle set screw. If this carburetor doesn't have this mixture screw, then clean and rebuild the carburetor.
Chase: How many rpms do you think my 8 HP Tecumseh can run at top speed?
John: The Red line is 4000 rpm's. Some people run higher, but the engines don't last long. My son's go-cart runs at 3800 to 4000 rpm's and is 3 yrs old. No problems as of yet, other than he's a little wild. Either in the ditch or he makes it all the way to the woods. lol.
Chase: So if I am building a racing cart frame say 100 pounds with a 52 tooth sprocket on the engine and a 19 one the transmission and I have 7 inch tires so the toatal cart should weigh around 150. I sould be going areound 30 mph right?
John: it's been a while, but I believe you to be fairly close. you will find a variation of approx 5 mph either way. altitude, terrain, humidity and the driver will all affect the outcome.
Chase: So on the road my gokart will go 5 mph. Any way to get it going faster?
John: LOL No. It should travel between 20 mph and 30 mph. If you really want more speed and have the tools to do it. I will tell you a secret. It will take some work, but I have seen it done and man did they fly. Locate an old 10 speed bicycle. Remove the 2 gear clusters and the shift assemblies. McGyver them to the engine and axle. It can be done. Now you can really go. I'm not sure of all the specifications on the gear clusters that were used on the one I saw at the track. I do know that there are several different ones. But he shifted it up and down and really seemed to enjoy the ride. This was about 20 years ago.
Chase: I don't think that will work. I am using a lawnmower transmission because I have a vertical shaft engine.
John: Reduce the size of the sprocket on the engine and this will increase the rpm's of the transmission input shaft. Rule of thumb. The closer the two sprockets are to the same number of teeth the higher the rpm' of the smaller sprocket. Remember also that at a certain point you will lose torque for dead starting. Dead starting is starting from a dead stop. When you locate the power curve, you can change the engine sprocket to suite the situation you are going to be using the go-kart for. Some people have 2 or 3 different engine sprockets to use depending on the track they will be running at.
Chase: I am going to use the sprocket spindle and take the chain from the bottom of the cart to this pulley shaft then to the top of the pulley shaft and to the transmission. I would go big on the engine then small on the bottom of the sprocket spindle then big on the top of it then small again on the sprocket right?
John: What kind of rear end are you using and what kind of transmission? If I understand you correctly, you are using a transmission and the go-kart rear end. I was thinking you were using a transaxle. You have the vertical shaft mower engine connected to the offset transmission and the offset transmission connected to the go-kart rear end?
Chase: What do you think a good number of teeth would be on the sockets? I am building the frame in my metals class. I am using a Peerless transaxle. The shaft is on top of the transaxle and on the bottom of the engine, so I am going to have a shaft betwen them with a chain running under the kart to the shaft in the middle then from the top of the shaft to the transaxle.
Answer Hello Chase:
The Sprocket Size on the Engine and on the Transaxle will be a Trial and Error Process. Using the Transaxle is a First for me. I have Put Car Tires and Rims on Farm Tractors and Raced them, but I never have done a Project like this. Start with the 52 and 19 and see how that Does. Then you can Decrease or Increase as Required. Always Increase or Decrease the Teeth on the Engine Sprocket. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks. Be Safe.
Good Luck
Respectfully
John
