Bought this project over a year ago for my daughter. She shows absolutely no interest in riding any of the other machines here(everyone is different). I did a bunch of work to it and then pushed it into the back of the shed. It was built for 90 Mod class racing.
2005 Blaster
2005 CR85 motor
Unknown +4+1 front arms
Works pro series front shocks
TRX450R rear shock
TPR gusset kit
CFM performance air box
YFZ450 radiator
Hinson Billet Proof clutch basket
Repairs and work done so far...
First, the previous builder ruined the expansion pipe. Which was also the wrong year and didn't seal to the head. They appeared to try to poorly mig weld it together with strips of steel and burnt several holes in it. Then it was wrapped in RTV coated header wrap. NO GO!
Engine mount holes were busted off and/or worn bigger. Wrong size bolts were used. I tore the engine down and cleaned it very thoroughly. New aluminum mounts were fabricated and tig welded to the case. I cleaned up the fabricated mounts on the frame, and used the correct size bolts with locking nuts to prevent this again.
I bought a clean used expansion chamber on flea-bay for the correct year. It was carefully cut at the seam, rotated, and tig welded back together. After that, it was just a matter of re-doing mount tabs to the frame and extending the end to meet the silencer. A YFM80 Badger handle bar was salvaged to make the exhaust extension.
The shifter was apparently stripped and they booger welded it to the shift shaft. I got a clean used shift shaft and used a YFM80 Badger shifter as a replacement. Just had to heat and bend the shifter to fit.
Ball-joints on the extended arms were worn badly. Also a PITA to find replacements. After a lot of searching, ended up using '79 Volkswagen Beetle steering ball joints. They fit perfect, and even solved an over travel issue that had bent the old ones. The original joints had an adapter sleave to make the upper joint a straight shaft. I made some new ones out of metric brass bushings.
I rebuilt the PWK28 carb. Put in the missing dowels in the engine, with new gaskets, after flat surfacing everything. This thing fires up second kick and sounds amazing. Just need to connect the motor to the rear axle to ride it.
Installed a used Fly Racing aluminum handle bar I had and replaced the bent up stock one. Used a silicone cooling hose kit with adapters to re-plumb the cooling to the YFZ450 radiator. Also had to relocate the mounting tabs to shift the radiator a bit for the new expansion chamber. I did use many parts from my fleet of part-out quads on this.
The reason this went to the back of the shed is adapting the output gear to the rear axle. I was not able to locate a 428 sprocket for the rear axle before. My plan to weld a 520 sprocket to a stock CR85 was a bad plan to begin with. The CR80/85 uses a "floating" sprocket. It is only meant to handle lateral force and floats on the output shaft side to side. So I shoved it out of the way to come back to it in the future.
I finally had some time and motivation. I went through every rear sprocket drawing in JT sprockets catalogue. Nearly admitting defeat, I finally found a 428 rear sprocket that was potentially viable. Its for Yamaha 125cc bikes only sold in the UK. The inner diameter was an exact match. I would only need to notch the mount holes towards the inside to fit the 6 bolt hub of the Blaster. And yes, I did search for 428 sprockets to fit the 4 bolt axle hub. So a 428 conversion CR80/85 JT front sprocket, and a JT rear sprocket for a TDR125/WR125. Sprocket Specialist said they could not make me a front sprocket. This was the biggest hurdle and was a huge amount of time to find a solution.
As it sits, I need to get the rear sprocket machined on a mill and I should, in theory, be able to finally run this thing. The rear sprocket I mentioned is available in 51, 52, 53, 55, 57 tooth. I bought a 53t, and a 15t front to get it to clear the swing arm. Should give me a shorter final ratio.
My personal quad is a 2007 Raptor 350. Its a Frankenstein creation, too. I'd also love to fix one of the other 3 Blasters I have and compare it to this CR85 Blaster. If I like this one, I'll get it dialed in, and sell it. Then try a 2-stroke bike 250 swap in another. I'm honestly too big and heavy to keep this build and ride it.
2005 Blaster
2005 CR85 motor
Unknown +4+1 front arms
Works pro series front shocks
TRX450R rear shock
TPR gusset kit
CFM performance air box
YFZ450 radiator
Hinson Billet Proof clutch basket
Repairs and work done so far...
First, the previous builder ruined the expansion pipe. Which was also the wrong year and didn't seal to the head. They appeared to try to poorly mig weld it together with strips of steel and burnt several holes in it. Then it was wrapped in RTV coated header wrap. NO GO!
Engine mount holes were busted off and/or worn bigger. Wrong size bolts were used. I tore the engine down and cleaned it very thoroughly. New aluminum mounts were fabricated and tig welded to the case. I cleaned up the fabricated mounts on the frame, and used the correct size bolts with locking nuts to prevent this again.
I bought a clean used expansion chamber on flea-bay for the correct year. It was carefully cut at the seam, rotated, and tig welded back together. After that, it was just a matter of re-doing mount tabs to the frame and extending the end to meet the silencer. A YFM80 Badger handle bar was salvaged to make the exhaust extension.
The shifter was apparently stripped and they booger welded it to the shift shaft. I got a clean used shift shaft and used a YFM80 Badger shifter as a replacement. Just had to heat and bend the shifter to fit.
Ball-joints on the extended arms were worn badly. Also a PITA to find replacements. After a lot of searching, ended up using '79 Volkswagen Beetle steering ball joints. They fit perfect, and even solved an over travel issue that had bent the old ones. The original joints had an adapter sleave to make the upper joint a straight shaft. I made some new ones out of metric brass bushings.
I rebuilt the PWK28 carb. Put in the missing dowels in the engine, with new gaskets, after flat surfacing everything. This thing fires up second kick and sounds amazing. Just need to connect the motor to the rear axle to ride it.
Installed a used Fly Racing aluminum handle bar I had and replaced the bent up stock one. Used a silicone cooling hose kit with adapters to re-plumb the cooling to the YFZ450 radiator. Also had to relocate the mounting tabs to shift the radiator a bit for the new expansion chamber. I did use many parts from my fleet of part-out quads on this.
The reason this went to the back of the shed is adapting the output gear to the rear axle. I was not able to locate a 428 sprocket for the rear axle before. My plan to weld a 520 sprocket to a stock CR85 was a bad plan to begin with. The CR80/85 uses a "floating" sprocket. It is only meant to handle lateral force and floats on the output shaft side to side. So I shoved it out of the way to come back to it in the future.
I finally had some time and motivation. I went through every rear sprocket drawing in JT sprockets catalogue. Nearly admitting defeat, I finally found a 428 rear sprocket that was potentially viable. Its for Yamaha 125cc bikes only sold in the UK. The inner diameter was an exact match. I would only need to notch the mount holes towards the inside to fit the 6 bolt hub of the Blaster. And yes, I did search for 428 sprockets to fit the 4 bolt axle hub. So a 428 conversion CR80/85 JT front sprocket, and a JT rear sprocket for a TDR125/WR125. Sprocket Specialist said they could not make me a front sprocket. This was the biggest hurdle and was a huge amount of time to find a solution.
As it sits, I need to get the rear sprocket machined on a mill and I should, in theory, be able to finally run this thing. The rear sprocket I mentioned is available in 51, 52, 53, 55, 57 tooth. I bought a 53t, and a 15t front to get it to clear the swing arm. Should give me a shorter final ratio.
My personal quad is a 2007 Raptor 350. Its a Frankenstein creation, too. I'd also love to fix one of the other 3 Blasters I have and compare it to this CR85 Blaster. If I like this one, I'll get it dialed in, and sell it. Then try a 2-stroke bike 250 swap in another. I'm honestly too big and heavy to keep this build and ride it.
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