dougy
Active Member
Just wanted to say Hi to everyone and thank you all for the information provided in this forum.
Growing up my mum would never let me near bikes because my dad had a bad accident when he was younger that left him with some brain damage. (a car failed to give way and he wasn't wearing a helmet).
I have a son that is 13 that visits each school holidays. Last year I decided to buy a go kart for us to play with as I has also missed out on all the fun when I was a kid.... My first purchase was a pump engine go kart with no suspension. After fixing it constantly we decided we needed something with suspension and something a bit faster. I bought a chinise buggy with a 140cc lifan that wouldn't run. I read up on all the wiring and in the end determined that the stator was not giving out a signal. When I pulled the side cover of I discovered that somebody had broken the crankshaft.... So I bought an old Honda CBR250 as a donor bike. Spent a month installing the engine. Unfortunately I could never get the chain sorted out entirely. I suspect it is because of the setup that I can't get enough tension on the chain. The chain jumps and clicks badly in first gear but seems to be OK once in 2nd, I'm guessing due to the reduced torque. Due to the chain issues and the dam thing not fitting in my 4x7 trailer it never got much use.
Last week I picked up a 125cc pit bike for $350 which I latter discovered may have been too much, the only good thing it had going for it was two new dunlop tyres. It was advertised as being a thumpstar but I latter learned that it is an orion apollo. The Vin plate shows it a 2007 build. When I picked it up the guy started it after a bit of trouble and I watched him ride up and down the road as I am somewhat experienced. Once I got it home a friend who rides road bikes came round. We found it very hard to start. As it warmed up it last all top end power. We decided that we wouldn't touch the carby till we did some research so finished up buy oiling the chain that was very dry and tensioning it as it was also very loose!
The next day I ordered a Mikuni 26mm Racing Carburetor Kit that came complete with the accelerator cable. I had opened up the existing carby and played around but I decided this was the surest way I would have the bike running well for the long weekend when my son came to visit. The carby made a huge difference but it was still hard to start at times but mostly when it was cold. When installing it we discovered that the accelerator assembly was badly worn. we were lucky to get the cable installed again, I will be ordering a new one this week before it gives out. I also changed the spark plug to a NGK as recommended by this forum. Something went wrong here.... I used anti-sieze and was careful but somehow managed to slightly strip the thread.... I have never done this in my life before and I still don't know why this happened. However the plug tightened up enough and the bike ran so we left it at this stage. Another problem that we experienced was at times the clutch cable would end up in the wrong spot and keep the clutch on. Haven't fulled solved this yet.
The next day we took the bike out riding. It was so much fun, I can't believe that I've never done it before. The bike was awesome, as much power as I need as a learner and a nice size to handle. It really had some go and still pulled really hard in 4th gear, I never got to wind it out all the way. I am really looking forward to going out again. One thing that we noticed was that due to a missing fuel breather that we got sprayed with fuel!
That evening the bike didn't want to start. In the end I pulled the spark plug out to check there was spark. This is when we were able to confirm that the thread was stripped.... but most of the damage was to the plug! I cleaned all the metal I could from the head but the plug would not tighten. I then put the old plug back in and it went in really well! Still the bike didn't want to start.
The next morning I decided to check the valve clearance. I found the specs on this forum and then found a youtube video that showed the procedure clearly. The gaps were very tight. once we set them correctly the bike started much easier.
Today I worked on the bike again. When I first started it the clutch wasn't disengaging for some reason. I confirmed it was not a cable problem and that I could push the clutch leaver down with a screwdriver. I sprayed it with WD40 and Inox. At first if made no difference but latter on seems to have sorted it out....
Next I discovered that it was an electric start model! The battery was missing so I fitted one I had out of my two year old daughters electric jeep. It is 12v 7ah battery like ones used in computer UPS's. here is a link to one
Brand NEW 12V 7 2AH UPS SLA Battery 12 Volt 7AH Sealed Lead Acid Rechargeable | eBay
The start button didn't do anything so in the end I ran one wire from the solenoid to the fuse connected to the battery and the other to the starter switch and grounded the other wire coming out of the switch. Now it turns over when I push the button, although it wasn't that successful at starting the bike, the only time if fired up under electric start was when it was fully warmed up. Not sure if a newer battery would help.
I also decided the exhaust needed work as it was a tad loose and the muffler had been completely opened up so it was extremely loud. The muffler from the 140 from the go kart seemed close enough but the pipe was bent sightly different and it didn't quite work. In the end I used the original pipe with the muffler from the go-kart and added a metal scouring pad to quieten it down. Unfortunately I didn't have a new exhaust ring/gasket so I used manifold sealant and also put it on all the other joins. It has worked well and really quietened the bike down.
The last problem I seem to have encountered is another carby problem. When I was working on the bike today I noticed that when I lent the bike onto the stand with the fuel on that fuel would drip out the overflow. This seems to have gotten worse and now even when the bike is standing up straight fuel still drips out the overflow...... unfortunately it looks like I am going to have to pull the new carby apart
any tips on whether this is likely to be dirt in the needle and seat or a float that needs adjusting?
here are the parts I will be ordering this week for the bike
Green Fuel Tank Breather 125cc Atomik PIT PRO PIT Bike Thumpster Dirt Bike | eBay
2X Petrol Fuel Filter Cleaner 50 110 125cc 250 Dirt Quad Bike ATV Buggy PIT PRO | eBay
Accelerate Throttle Grip Housing 85cm Cable PIT PRO Trail Dirt Bike Thumpstar | eBay
And as a reward for anyone who managed to read all of the above, here are some pics of the bike!
UPDATE: on advice from another friend who had owned bikes in the past, I turned on the fuel and let the bowl fill then turned it off and drained the bowl again twice. The needle and seat seem to have been flushed out and are sealing again as fuel does not leak from the overflow now!
Growing up my mum would never let me near bikes because my dad had a bad accident when he was younger that left him with some brain damage. (a car failed to give way and he wasn't wearing a helmet).
I have a son that is 13 that visits each school holidays. Last year I decided to buy a go kart for us to play with as I has also missed out on all the fun when I was a kid.... My first purchase was a pump engine go kart with no suspension. After fixing it constantly we decided we needed something with suspension and something a bit faster. I bought a chinise buggy with a 140cc lifan that wouldn't run. I read up on all the wiring and in the end determined that the stator was not giving out a signal. When I pulled the side cover of I discovered that somebody had broken the crankshaft.... So I bought an old Honda CBR250 as a donor bike. Spent a month installing the engine. Unfortunately I could never get the chain sorted out entirely. I suspect it is because of the setup that I can't get enough tension on the chain. The chain jumps and clicks badly in first gear but seems to be OK once in 2nd, I'm guessing due to the reduced torque. Due to the chain issues and the dam thing not fitting in my 4x7 trailer it never got much use.
Last week I picked up a 125cc pit bike for $350 which I latter discovered may have been too much, the only good thing it had going for it was two new dunlop tyres. It was advertised as being a thumpstar but I latter learned that it is an orion apollo. The Vin plate shows it a 2007 build. When I picked it up the guy started it after a bit of trouble and I watched him ride up and down the road as I am somewhat experienced. Once I got it home a friend who rides road bikes came round. We found it very hard to start. As it warmed up it last all top end power. We decided that we wouldn't touch the carby till we did some research so finished up buy oiling the chain that was very dry and tensioning it as it was also very loose!
The next day I ordered a Mikuni 26mm Racing Carburetor Kit that came complete with the accelerator cable. I had opened up the existing carby and played around but I decided this was the surest way I would have the bike running well for the long weekend when my son came to visit. The carby made a huge difference but it was still hard to start at times but mostly when it was cold. When installing it we discovered that the accelerator assembly was badly worn. we were lucky to get the cable installed again, I will be ordering a new one this week before it gives out. I also changed the spark plug to a NGK as recommended by this forum. Something went wrong here.... I used anti-sieze and was careful but somehow managed to slightly strip the thread.... I have never done this in my life before and I still don't know why this happened. However the plug tightened up enough and the bike ran so we left it at this stage. Another problem that we experienced was at times the clutch cable would end up in the wrong spot and keep the clutch on. Haven't fulled solved this yet.
The next day we took the bike out riding. It was so much fun, I can't believe that I've never done it before. The bike was awesome, as much power as I need as a learner and a nice size to handle. It really had some go and still pulled really hard in 4th gear, I never got to wind it out all the way. I am really looking forward to going out again. One thing that we noticed was that due to a missing fuel breather that we got sprayed with fuel!
That evening the bike didn't want to start. In the end I pulled the spark plug out to check there was spark. This is when we were able to confirm that the thread was stripped.... but most of the damage was to the plug! I cleaned all the metal I could from the head but the plug would not tighten. I then put the old plug back in and it went in really well! Still the bike didn't want to start.
The next morning I decided to check the valve clearance. I found the specs on this forum and then found a youtube video that showed the procedure clearly. The gaps were very tight. once we set them correctly the bike started much easier.
Today I worked on the bike again. When I first started it the clutch wasn't disengaging for some reason. I confirmed it was not a cable problem and that I could push the clutch leaver down with a screwdriver. I sprayed it with WD40 and Inox. At first if made no difference but latter on seems to have sorted it out....
Next I discovered that it was an electric start model! The battery was missing so I fitted one I had out of my two year old daughters electric jeep. It is 12v 7ah battery like ones used in computer UPS's. here is a link to one
Brand NEW 12V 7 2AH UPS SLA Battery 12 Volt 7AH Sealed Lead Acid Rechargeable | eBay
The start button didn't do anything so in the end I ran one wire from the solenoid to the fuse connected to the battery and the other to the starter switch and grounded the other wire coming out of the switch. Now it turns over when I push the button, although it wasn't that successful at starting the bike, the only time if fired up under electric start was when it was fully warmed up. Not sure if a newer battery would help.
I also decided the exhaust needed work as it was a tad loose and the muffler had been completely opened up so it was extremely loud. The muffler from the 140 from the go kart seemed close enough but the pipe was bent sightly different and it didn't quite work. In the end I used the original pipe with the muffler from the go-kart and added a metal scouring pad to quieten it down. Unfortunately I didn't have a new exhaust ring/gasket so I used manifold sealant and also put it on all the other joins. It has worked well and really quietened the bike down.
The last problem I seem to have encountered is another carby problem. When I was working on the bike today I noticed that when I lent the bike onto the stand with the fuel on that fuel would drip out the overflow. This seems to have gotten worse and now even when the bike is standing up straight fuel still drips out the overflow...... unfortunately it looks like I am going to have to pull the new carby apart
any tips on whether this is likely to be dirt in the needle and seat or a float that needs adjusting?here are the parts I will be ordering this week for the bike
Green Fuel Tank Breather 125cc Atomik PIT PRO PIT Bike Thumpster Dirt Bike | eBay
2X Petrol Fuel Filter Cleaner 50 110 125cc 250 Dirt Quad Bike ATV Buggy PIT PRO | eBay
Accelerate Throttle Grip Housing 85cm Cable PIT PRO Trail Dirt Bike Thumpstar | eBay
And as a reward for anyone who managed to read all of the above, here are some pics of the bike!
UPDATE: on advice from another friend who had owned bikes in the past, I turned on the fuel and let the bowl fill then turned it off and drained the bowl again twice. The needle and seat seem to have been flushed out and are sealing again as fuel does not leak from the overflow now!
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