Doc Sprocket
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Still sounds like it's starving, and badly. This is based on the assumption that it's not hitting hard enough to keep the momentum, but keeping the starter engaged makes up for it.
how does this sound?
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Tim14527
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Few Questions
First your build looks great. Very impressive! I really liked the "stretch" and ground clearance still looked great. It has been many years since I worked in a fabrication shop so let's just say I'm pretty rusty now and probably have corrosion issues too! Okay, why are these frames being built with square stock over round? This is not being critical of the build but back in the day I was taught round was stronger. Is the square stock for weight issues? Next, I would have loved to see this motor and a shifter worked out. I was thinking a linkage shifter of some sort but couldn't figure a suggestion based on the photos and build, I think cables would have been the bigger challenge with the exception of a linkage to cable with a external tension return to help with neutral and notched position guide plate for each gear. You've got a great frame there, why not go back to the original 16hp you were planning on? There always seems to be issues when using used motors off of bikes unless you have a proven pattern to follow with a motor that has low miles and you heard run before the mounting process. Of course you lose your bragging rights when it's your own design that was perfected and others start using it! I hate to see this build at a stand still! Where are you at now? Interesting thread, learned a lot, great "jig" idea!
First your build looks great. Very impressive! I really liked the "stretch" and ground clearance still looked great. It has been many years since I worked in a fabrication shop so let's just say I'm pretty rusty now and probably have corrosion issues too! Okay, why are these frames being built with square stock over round? This is not being critical of the build but back in the day I was taught round was stronger. Is the square stock for weight issues? Next, I would have loved to see this motor and a shifter worked out. I was thinking a linkage shifter of some sort but couldn't figure a suggestion based on the photos and build, I think cables would have been the bigger challenge with the exception of a linkage to cable with a external tension return to help with neutral and notched position guide plate for each gear. You've got a great frame there, why not go back to the original 16hp you were planning on? There always seems to be issues when using used motors off of bikes unless you have a proven pattern to follow with a motor that has low miles and you heard run before the mounting process. Of course you lose your bragging rights when it's your own design that was perfected and others start using it! I hate to see this build at a stand still! Where are you at now? Interesting thread, learned a lot, great "jig" idea!
CAPTAINCAVEMAN
Member
^ thank you: when I started this build I just wanted the experience of building so the engine was just another exiting challenge. the square tube is due to lack of: tube bender, tube notcher, the plans called for square, and it is easier to weld in my opinion which is good because I am not an expert welder. the only reason the build is going slow right now is I am in high school and there is little time for me to work on it
toystory: I took the carbs apart and looked through jets and things they looked very clean, what could be slowing gas flow?
I don't know if it matters but right now there are no air filters on it because I am just running garage tests right now. I will put them on before riding
toystory: I took the carbs apart and looked through jets and things they looked very clean, what could be slowing gas flow?
I don't know if it matters but right now there are no air filters on it because I am just running garage tests right now. I will put them on before riding
CAPTAINCAVEMAN
Member
good and bad news
with help from my friend we got the engine to start. after a bit of time the only thing wrong was that one cylinder was not firing. there is no spark but I don't know why
with help from my friend we got the engine to start. after a bit of time the only thing wrong was that one cylinder was not firing. there is no spark but I don't know why
Tim14527
New member
Agreed, a good tube bender is critical, especially for precise bends, you can make jigs once you have a design and use heat but that's not important now. You will be a great welder learning on anything! Excluding the motor, what was the total cost of material and what motor did original plans suggest?
CAPTAINCAVEMAN
Member
I am a proficient welder but when I started this project I was timid about welding tube. I think the plans called for a 10hp Tecumseh but I don't know and don't want to know how much I have spent on this so far
CAPTAINCAVEMAN
Member
I figured out the plug as well as the connector on that cylinder were bad so I replaced all the plugs just in case and also replaced the connector. it now has very good spark in all cylinders. 
CAPTAINCAVEMAN
Member
thanks...... I think
all four cylinders now run but the middle two run kinda rough when at idle. this is after I replaced the plugs on all cylinders as well as the connectors on the outside two. do you think the middle two need the connectors replaced also? otherwise what is causing them to not idle well.
also if I restrict the air to those carbs it revs up and runs better for a few seconds after I unrestricted it.
if that doesn't make sense I will clarify later but any suggestions are welcome.
all four cylinders now run but the middle two run kinda rough when at idle. this is after I replaced the plugs on all cylinders as well as the connectors on the outside two. do you think the middle two need the connectors replaced also? otherwise what is causing them to not idle well.
also if I restrict the air to those carbs it revs up and runs better for a few seconds after I unrestricted it.
if that doesn't make sense I will clarify later but any suggestions are welcome.
tomas02
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Hi Guys.
Been a long time since I posted here.
But found this thread interesting. I have the exact same motor sitting in the shed at home. To get mine started when I bought it, I had to get the carbs synced and soak the jets in carb cleaner for a few days.
Also have you worked out the gear shifter yet?
I made a kart with a rear swingarm and a GSXR250 and had to use solid linkages. It works extremely well if pivoted off the same point the swingarm is and bumps won't shift gears that way.
There is video in this thread somwhere to explain the shifter:
http://www.diygokarts.com/vb/showthread.php?t=13665
Hope it goes well.
I'll be watching
Been a long time since I posted here.
But found this thread interesting. I have the exact same motor sitting in the shed at home. To get mine started when I bought it, I had to get the carbs synced and soak the jets in carb cleaner for a few days.
Also have you worked out the gear shifter yet?
I made a kart with a rear swingarm and a GSXR250 and had to use solid linkages. It works extremely well if pivoted off the same point the swingarm is and bumps won't shift gears that way.
There is video in this thread somwhere to explain the shifter:
http://www.diygokarts.com/vb/showthread.php?t=13665
Hope it goes well.
I'll be watching
CAPTAINCAVEMAN
Member
thanks: for the shifter I am going to try using 2 cables, one to shift up one to shift down, but if that doesn't work like I want it to I will try something similar to what you have done.
this is the last week of school for the next 3 months so I will be back to work on this very soon. in the summer I have a steady job so I will have the money to buy the parts I need
this is the last week of school for the next 3 months so I will be back to work on this very soon. in the summer I have a steady job so I will have the money to buy the parts I need
CAPTAINCAVEMAN
Member
the cable idea for the shifter has worked so far. I know it has been a long time since I updated everybody but I have made progress: I built a roll cage and installed the seat and seatbelt. I also got the clutch working. 
I even attempted a test drive but the shaft that I had the idler pulley/ Chain tensioner on bent when I took off, I am now trying to fabricate a spring loaded version so that there will be some give.
the clutch cable however is not strong enough so I will also have to order a new one.
I even attempted a test drive but the shaft that I had the idler pulley/ Chain tensioner on bent when I took off, I am now trying to fabricate a spring loaded version so that there will be some give.
the clutch cable however is not strong enough so I will also have to order a new one.
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chris_the_poser
Member
Cool get this thing done and get some videos. It's pretty sweet.
CAPTAINCAVEMAN
Member
everything is hooked up and I took another test run
the engine will not keep running when I take off it will dig holes but it dies almost immediately any ideas I think it might not be getting enough gas but that would mean a clogged jet or multiple clogged jets and I checked the whole set of carburetors before I installed them.
the engine will not keep running when I take off it will dig holes but it dies almost immediately any ideas I think it might not be getting enough gas but that would mean a clogged jet or multiple clogged jets and I checked the whole set of carburetors before I installed them.
CAPTAINCAVEMAN
Member
I drove it successfully around the roads but I need to muffle it because it is LOUD 
update: I found that I can get it going but it is hard to not pop the clutch and the gearing is very high
, about 2.8:1 if I remembered the amount of teeth correctly. my problem is I don't have room for a larger sprocket on the axle so until I get the notion to do some major mods it will just have to be like that.
edit: I did some major mods, I lifted the frame and put a larger sprocket on but it is still a bad ratio. the new adjustable idler works and I am almost finished building a trailer for it.
update: I found that I can get it going but it is hard to not pop the clutch and the gearing is very high
, about 2.8:1 if I remembered the amount of teeth correctly. my problem is I don't have room for a larger sprocket on the axle so until I get the notion to do some major mods it will just have to be like that.edit: I did some major mods, I lifted the frame and put a larger sprocket on but it is still a bad ratio. the new adjustable idler works and I am almost finished building a trailer for it.
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