Re: Cobrafreak's board track racer project now COMPLETED!!!
OK... Good luck and keep us posted.
OK... Good luck and keep us posted.
Cobrafreak's board track racer project, has ended
- Thread starter cobrafreak
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Re: Cobrafreak's board track racer project now COMPLETED!!!
That 4-stroke sound will work so well with the look of your bike. Great stuff! A ratrod (somehow it feels wrong to call your masterpiece a ratrod, but anyhoo) is never finished :mrgreen:
That 4-stroke sound will work so well with the look of your bike. Great stuff! A ratrod (somehow it feels wrong to call your masterpiece a ratrod, but anyhoo) is never finished :mrgreen:
Re: Cobrafreak's board track racer project, never ends!
I may have been a little harsh on the 2 stroke engine. All my problems stemmed from a bad spark plug wire. Everything is fine now. I need to realize that there is a slight learning curve to operating and maintaining a 2 stroke engine. It's pretty simple stuff, not rocket science. Live and learn. What I did find out is that even though you pull the plug, and have it in the spark plug boot grounded to the engine and see a bright visible spark when you turn it over does not mean the spark is powerful enough to support combustion. I must have checked it 4 times before I asked for help from a 2 stroke mechanic. The "clue" was a single audible "pop" when attempting to start. The sound was the current not making it to the plug apparently. I will keep the motor I have and just seek help for the extra "special" problems.
I may have been a little harsh on the 2 stroke engine. All my problems stemmed from a bad spark plug wire. Everything is fine now. I need to realize that there is a slight learning curve to operating and maintaining a 2 stroke engine. It's pretty simple stuff, not rocket science. Live and learn. What I did find out is that even though you pull the plug, and have it in the spark plug boot grounded to the engine and see a bright visible spark when you turn it over does not mean the spark is powerful enough to support combustion. I must have checked it 4 times before I asked for help from a 2 stroke mechanic. The "clue" was a single audible "pop" when attempting to start. The sound was the current not making it to the plug apparently. I will keep the motor I have and just seek help for the extra "special" problems.
Re: Cobrafreak's board track racer project, never ends!
You are realizing what I mean when I say I dislike the Chinese engines. Right when you get them broke in, they blow up. That's the nature of the beast and why parts are super cheap. There's a pretty large group of fellas here with them and they all have constant problems. They seem to be good for about 4-600 miles then they go.
My briggs was also doing the "pop" last night". Maybe my 50 yo spark plug wire that's all crack is causing it. Thank!
Keep it up!
You are realizing what I mean when I say I dislike the Chinese engines. Right when you get them broke in, they blow up. That's the nature of the beast and why parts are super cheap. There's a pretty large group of fellas here with them and they all have constant problems. They seem to be good for about 4-600 miles then they go.
My briggs was also doing the "pop" last night". Maybe my 50 yo spark plug wire that's all crack is causing it. Thank!
Keep it up!
Re: Cobrafreak's board track racer project, never ends!
It was probably the spark plug cap more than the spark plug wire, but it's all new now. I'm don't have a speedometer or tripometer but I know exactly how much fuel has gone through my engine. With milage claims from the factory from between 100 mpg to 150 mpg I have on the low end 500 miles and 750 miles on the high end. So I'll probably split the difference in the name of science. Say 625 miles so far and it is running well now, after my spark plug wire fiasco. On http://www.motorbikes.com there are guys with 3K+ on the same engine. They say if you run it full balls out all the time it will not last. If you cruise at around 60 to 75% throttle all the time and just gun it for occasional bursts of speed when you need it then you will get more life out of it. Just gear it for the speed you want to go. It's more of a low end torque engine rather than a high end screamer anyway. So I'm constantly learning on this thing. Checking the head gasket torque "daily". Replace the cheap Chinese spark plug, spark plug wire, and boot as soon as you open the box! Mix the oil on the liberal side of the scale. It is what lubes the engine. I'll stick with it for now. If I am going through more than two engines in a calendar year then I will probably move to 4 stroke power. Not looking forward to a complete engine changeover, at least right now. I just got all the feeling back in my hands from the initial build! Lol! Getting old is not fun in some respects. :lol:
It was probably the spark plug cap more than the spark plug wire, but it's all new now. I'm don't have a speedometer or tripometer but I know exactly how much fuel has gone through my engine. With milage claims from the factory from between 100 mpg to 150 mpg I have on the low end 500 miles and 750 miles on the high end. So I'll probably split the difference in the name of science. Say 625 miles so far and it is running well now, after my spark plug wire fiasco. On http://www.motorbikes.com there are guys with 3K+ on the same engine. They say if you run it full balls out all the time it will not last. If you cruise at around 60 to 75% throttle all the time and just gun it for occasional bursts of speed when you need it then you will get more life out of it. Just gear it for the speed you want to go. It's more of a low end torque engine rather than a high end screamer anyway. So I'm constantly learning on this thing. Checking the head gasket torque "daily". Replace the cheap Chinese spark plug, spark plug wire, and boot as soon as you open the box! Mix the oil on the liberal side of the scale. It is what lubes the engine. I'll stick with it for now. If I am going through more than two engines in a calendar year then I will probably move to 4 stroke power. Not looking forward to a complete engine changeover, at least right now. I just got all the feeling back in my hands from the initial build! Lol! Getting old is not fun in some respects. :lol:
Re: Cobrafreak's board track racer project, never ends!
I think you need a bit off luck with these china engines.. If you get a dud you can have all sorts of problems with it or if you get a good one they run well for a reasonable time given the prize you pay for it..
The one on my BTR have been running good all summer without any problems.. Don't know the milage on it but i used it almost daily..
I think you need a bit off luck with these china engines.. If you get a dud you can have all sorts of problems with it or if you get a good one they run well for a reasonable time given the prize you pay for it..
The one on my BTR have been running good all summer without any problems.. Don't know the milage on it but i used it almost daily..
Re: Cobrafreak's board track racer project, never ends!
I have been looking for a bit more run ability and power and I found a simple and cheap way to do it. I made a drawing:
I reasoned that the hole coming out of the engine is much larger that the one going out of the muffler, thus creating a restriction. I measured the existing exhaust hole at 13/16". I simply drilled another 13/16" hole next to it. WOW! Significant power increase, especially low end power. The response is better. Climbing up hills is no problem at all. Thet exhaust flow coming out of the engine now is so much greater that it was necessary to move the carb needle valve clip all the way down to the bottom so the needle is at the uppermost position. After all, the fuel being burned is what is making the power. More fuel burning, more power. If you don't move the clip down/needle valve up you wont make any gains. The sound is louder, but not too loud. Much louder if you remove the entire bottom of the muffler off. I measured it at idle at 90 - 92 db. Putting around the neighborhood slow is not too loud. Getting on it is a little louder. loud enough for me to wear ear plugs because I don't like too much noise. You make the call on this. I think the trade-off is well worth it. If you don't like it you can always weld the hole back up or put a bolt and nut in it to plug it up.
I have been looking for a bit more run ability and power and I found a simple and cheap way to do it. I made a drawing:
I reasoned that the hole coming out of the engine is much larger that the one going out of the muffler, thus creating a restriction. I measured the existing exhaust hole at 13/16". I simply drilled another 13/16" hole next to it. WOW! Significant power increase, especially low end power. The response is better. Climbing up hills is no problem at all. Thet exhaust flow coming out of the engine now is so much greater that it was necessary to move the carb needle valve clip all the way down to the bottom so the needle is at the uppermost position. After all, the fuel being burned is what is making the power. More fuel burning, more power. If you don't move the clip down/needle valve up you wont make any gains. The sound is louder, but not too loud. Much louder if you remove the entire bottom of the muffler off. I measured it at idle at 90 - 92 db. Putting around the neighborhood slow is not too loud. Getting on it is a little louder. loud enough for me to wear ear plugs because I don't like too much noise. You make the call on this. I think the trade-off is well worth it. If you don't like it you can always weld the hole back up or put a bolt and nut in it to plug it up.
Re: Cobrafreak's board track racer project, never ends!
:mrgreen: old man :mrgreen:im just messing with you,cause i run chainsaws with pretty much straight pipes :mrgreen: and ear protection is only for nitro pro dragsterscobrafreak said:
Re: Cobrafreak's board track racer project, never ends!
this bike is very very cool. but you said you did the reg on line so what would stop you from using a flatty and say it is 49cc. i mean is a cop really going to pull the head and cc the engine? especially if you were cool about ridding it around. (not saying anyone should break the law just saying a flatty is not going to be faster than these 2 strokes and thinks it is stupid that they get called motor cycles)
this bike is very very cool. but you said you did the reg on line so what would stop you from using a flatty and say it is 49cc. i mean is a cop really going to pull the head and cc the engine? especially if you were cool about ridding it around. (not saying anyone should break the law just saying a flatty is not going to be faster than these 2 strokes and thinks it is stupid that they get called motor cycles)
Re: Cobrafreak's board track racer project, never ends!
Just ride sanely and nobody will care. Obey all street signs, speed limits, and general laws and there will always be bigger fish to fry.
karfer67 said:
Just ride sanely and nobody will care. Obey all street signs, speed limits, and general laws and there will always be bigger fish to fry.
Re: Cobrafreak's board track racer project, never ends!
New detail stuff. I found these on Ebay (I love Ebay) They are brass biker pins, about 2" in diameter. I took the pin off of the back and siliconed them to my engine cases. I thought it would be a simple way to add a little class.
New detail stuff. I found these on Ebay (I love Ebay) They are brass biker pins, about 2" in diameter. I took the pin off of the back and siliconed them to my engine cases. I thought it would be a simple way to add a little class.
Re: Cobrafreak's board track racer project, never ends!
My friend Adam came over to see my Indian and really wanted to ride it never having ridden anything with two wheels and an engine. He did alright. Here is the You Tube link:
http://www.youtube.com/watch?v=HJPK6SbDEjE
My friend Adam came over to see my Indian and really wanted to ride it never having ridden anything with two wheels and an engine. He did alright. Here is the You Tube link:
http://www.youtube.com/watch?v=HJPK6SbDEjE
Re: Cobrafreak's board track racer project, never ends!
My old school brass bugle air horn came in today. I measured it with my decibel meter at 110! stinkin' loud! It was too shiny and perfect so I added scuffs, dings, bends, and dents. looks old now.
My old school brass bugle air horn came in today. I measured it with my decibel meter at 110! stinkin' loud! It was too shiny and perfect so I added scuffs, dings, bends, and dents. looks old now.
Re: Cobrafreak's board track racer project, never ends!
I got a flat tire last week and it occurred to me that I really need to take tools with me to fix things when they strand me. So I picked up this cool leather tool pouch that will let me take wrenches, pump, flat repair kit, spare tube, etc. No more stuffing my pockets with wrenches. "Hey, are you ready to fix something or are you just glad to see me..." Lol.
I got a flat tire last week and it occurred to me that I really need to take tools with me to fix things when they strand me. So I picked up this cool leather tool pouch that will let me take wrenches, pump, flat repair kit, spare tube, etc. No more stuffing my pockets with wrenches. "Hey, are you ready to fix something or are you just glad to see me..." Lol.
Re: Cobrafreak's board track racer project, never ends!
Happy to report that after adjusting the head bolts for a few weeks to 120 inch lbs the day after every ride (so that the engine is dead cold and thus no heat expansion) It is getting to the point that the engine stays in adjustment. It took over 21 adjustments for the case, head, cylinder, head bolts, and nuts to seat in properly. Compression is great, power is great. I've always heard that these little Chinese engines are hand grenades but I have never heard of anyone paying as much attention to the head torque as me. I'm wondering if one of the reasons for the bad rap is the engine just gets looser and looser due to bolt torque loosening up until something eventually breaks off? The head gasket is very thin aluminum and very soft and it is going to squash a lot (apparently) to seal in the combustion chamber gasses. Eventually it is going to get to the point where it will not crush any more and not need as frequent re-torquing. I bet if the owners manual was more clear on how important this issue is and when and how often to adjust the torque the majority of these engines would last much longer. Time will tell. Oh, BTW, The owners manuel specifies less torque than the factory online website for these engines. 120 inch lbs is about 10 more than the paper manuel. The 10 extra lbs is probably a better idea and the factory realized this, but for some reason did not update the actual paperwork that comes with the engine. Crazy.
Happy to report that after adjusting the head bolts for a few weeks to 120 inch lbs the day after every ride (so that the engine is dead cold and thus no heat expansion) It is getting to the point that the engine stays in adjustment. It took over 21 adjustments for the case, head, cylinder, head bolts, and nuts to seat in properly. Compression is great, power is great. I've always heard that these little Chinese engines are hand grenades but I have never heard of anyone paying as much attention to the head torque as me. I'm wondering if one of the reasons for the bad rap is the engine just gets looser and looser due to bolt torque loosening up until something eventually breaks off? The head gasket is very thin aluminum and very soft and it is going to squash a lot (apparently) to seal in the combustion chamber gasses. Eventually it is going to get to the point where it will not crush any more and not need as frequent re-torquing. I bet if the owners manual was more clear on how important this issue is and when and how often to adjust the torque the majority of these engines would last much longer. Time will tell. Oh, BTW, The owners manuel specifies less torque than the factory online website for these engines. 120 inch lbs is about 10 more than the paper manuel. The 10 extra lbs is probably a better idea and the factory realized this, but for some reason did not update the actual paperwork that comes with the engine. Crazy.
Re: Cobrafreak's board track racer project, never ends!
I am in the process of revising my front end. The bike was too short so I'm adding 1.25" of length by fabricating new leading links on the front fork. I am also going to lower the front end and then fabricate new handlebars. Looked too much "mountain bike" for me.
I am in the process of revising my front end. The bike was too short so I'm adding 1.25" of length by fabricating new leading links on the front fork. I am also going to lower the front end and then fabricate new handlebars. Looked too much "mountain bike" for me.
Re: Cobrafreak's board track racer project, never ends!
Heck yeah!
It will look great.
While you're at it why don't you build one of those leaf suspension forks?
Keep rollin'
Heck yeah!
It will look great.
While you're at it why don't you build one of those leaf suspension forks?
Keep rollin'
Re: Cobrafreak's board track racer project, never ends!
Here is a picture of my new forward links on the front fork. They are 1.25" longer than the originals, thus the wheelbase is stretched 1.25" overall. The bike is much more comfortable to ride and the fork looks more like a motorcycle fork.
Here is a picture of my new forward links on the front fork. They are 1.25" longer than the originals, thus the wheelbase is stretched 1.25" overall. The bike is much more comfortable to ride and the fork looks more like a motorcycle fork.
Re: Cobrafreak's board track racer project, never ends!
I made new handlebars. I had a length of gas pipe (I love gas pipe) that had new handlebars all over it. I went old school and made them sweeping wide and since it is an old school sport bike I went with downward rake. I got rid of the mountain bike stem that was way too modern looking for the ride and got a BMX down hill thread-less stem with a short 50mm reach. FYI, BMX handlebars are narrower and wont work with regular bicycle stuff, but it fits gas pipe perfect!
I made new handlebars. I had a length of gas pipe (I love gas pipe) that had new handlebars all over it. I went old school and made them sweeping wide and since it is an old school sport bike I went with downward rake. I got rid of the mountain bike stem that was way too modern looking for the ride and got a BMX down hill thread-less stem with a short 50mm reach. FYI, BMX handlebars are narrower and wont work with regular bicycle stuff, but it fits gas pipe perfect!
