Howdy folks, I've been lurking here for a good couple of months and have spent a lot of time reading the forum.
tl:dr YFS200 idles great, bogs with any throttle.
Started after replacing OEM ignition with cheap chinese, two day from Amazon parts.
Nitty Gritty deets below.
I recently purchased a 2000 Yamaha Blaster that ran, but not well. It would bog at anything over about a quarter throttle. Previous owner said it was probably due to a cracked reed. I've never owned anything 2-stroke beyond a chainsaw and leaf blower, so this is a new experience for me.
It came with an FMF Fatty pipe and FMF Power Core 2 Silencer. Previous owner said he swapped the carb out to get it to run.
I rode the quad for about two days and had one of the screws in the flywheel back itself out and make contact with the housing stopping me dead in my tracks. I removed the bent screw, tightened the rest down, and continued to ride, sans that screw. (My first thought was to pull all the screws one at a time and lock-tight each one, but...I was in a hurry to enjoy the new toy...) So a day later, I lost a second screw, on the same magnet that I had lost the first screw from, and absolutely seized the motor.
I thought I had burnt it up, but thankfully, as soon as I pulled the flywheel, it turned over great! By this time, I had already pulled the motor and head to check the piston either way and it was in pretty rough shape.
I figured since I lost a magnet and seized the whole kit and kaboodle, I should probably replace the stator in case it was damaged, so I ordered an el-cheapo YFS200 rated ignition kit (Adjustable Stator Plate with Coils, CDI, Ignition Coil, Spark Plug) from Amazon (because I am not a patient man, and boy does that one to two day shipping satisfy my instant gratification). Instead of installing the adjustable plate, I decided to use my handy soldering iron skills to just replace the components on the stock plate with the coils and pickup from the adjustable one. This was to keep from throwing the timing off, or so I thought....
I put everything back together and come to find out, the motor now kicks back every third or fourth kick and tries to break my leg. So I think maybe the plate is off ever so slightly... well, after many hours of adjustment, ordering a second adjustable plate, and trying to adjust timing using the adjustable plate, I find out the pickup on the new plate has a completely different resistance value and is throwing timing ALL out of whack.
So back to original pickup on stock plate with Amazon stator coils. Fires up, but only after many kicks and bogs like a madman outside of idle.
Side note at this point, the threads for the flywheel on the crank are shot so I'm running the nut without washer just to get 4 threads or so onto the nut. I really don't want to split the case to replace the crank....
So I checked compression and found I was around 80 PSI, so off to the Amazon jug and piston store I went thinking this was a compression issue.
One new cylinder and piston later and I have discovered I've got a Vitos +3MM Stroker crank, so I reused the spacer plate with two new gaskets.
While in there, I replaced the reeds, which weren't actually in terrible condition.
I also bought a set of main jets because I wasn't sure what was in there (since the P.O. "just swapped out the carb") and wanted to make sure I wasn't running lean on a new cylinder and piston. Main jet is now a 270. The one that came out looked like it was well under #200.... I am skeptical as to whether or not the pilot jet is the correct size now at this point, but haven't checked....
Built a pressure tester, because they are apparently incredibly important for 2-strokes (especially our blasters) and made sure it held 7PSI for a good 5 minutes or so. Much to my chagrin, it took me a couple of days to figure out it was leaking from the tester and not the motor.....
So now, I have around 150PSI compression, it fires on the first or second kick, idles like a champ, but BOGS with any amount of throttle. LOTS of blue smoke out the back. It also kind of sounds like it's not firing every compression stroke. I have a tiny blue spark that you can hear and see when you crank it with the plug against the case.
I'm starting to think the el-cheapo coils are a terrible idea and I should be looking for OEM replacements or at the very least, the moose kit. The Ignition coil and plug boot only fit the plug if I remove the tip. The one I pulled off the blaster fit the whole tip of the plug.
Unfortunately, the only two parts I didn't save in this whole process were the original charge coil and ignition coil and those are the only two things that could be effecting this mess to the best of my knowledge.
Somewhere in here, I also balked at how much the clutch had been futzed with to compensate for not having the steel ball in between the two rods. I've since replaced the clutch, the steel ball (or added rather) and the outer rod as I couldn't get the inner rod to slide out. Now the clutch is properly aligned and engages/disengages correctly without bending the bracket on the block and adding a bunch of washers (as it had when I originally purchased it).
This little blasty has been awesome so far and I really wanna ride it!
Here is a video of how it runs now.
Here is a video of the spark across the gap @ .030 ± .002. It's in slow mo!
I don't want to spend 150+ on a used OEM eBay stator, may I use the Moose Kit from MotoSport?
Any other thoughts or comments would be greatly appreciated.
tl:dr YFS200 idles great, bogs with any throttle.
Started after replacing OEM ignition with cheap chinese, two day from Amazon parts.
Nitty Gritty deets below.
I recently purchased a 2000 Yamaha Blaster that ran, but not well. It would bog at anything over about a quarter throttle. Previous owner said it was probably due to a cracked reed. I've never owned anything 2-stroke beyond a chainsaw and leaf blower, so this is a new experience for me.
It came with an FMF Fatty pipe and FMF Power Core 2 Silencer. Previous owner said he swapped the carb out to get it to run.
I rode the quad for about two days and had one of the screws in the flywheel back itself out and make contact with the housing stopping me dead in my tracks. I removed the bent screw, tightened the rest down, and continued to ride, sans that screw. (My first thought was to pull all the screws one at a time and lock-tight each one, but...I was in a hurry to enjoy the new toy...) So a day later, I lost a second screw, on the same magnet that I had lost the first screw from, and absolutely seized the motor.
I thought I had burnt it up, but thankfully, as soon as I pulled the flywheel, it turned over great! By this time, I had already pulled the motor and head to check the piston either way and it was in pretty rough shape.
I figured since I lost a magnet and seized the whole kit and kaboodle, I should probably replace the stator in case it was damaged, so I ordered an el-cheapo YFS200 rated ignition kit (Adjustable Stator Plate with Coils, CDI, Ignition Coil, Spark Plug) from Amazon (because I am not a patient man, and boy does that one to two day shipping satisfy my instant gratification). Instead of installing the adjustable plate, I decided to use my handy soldering iron skills to just replace the components on the stock plate with the coils and pickup from the adjustable one. This was to keep from throwing the timing off, or so I thought....
I put everything back together and come to find out, the motor now kicks back every third or fourth kick and tries to break my leg. So I think maybe the plate is off ever so slightly... well, after many hours of adjustment, ordering a second adjustable plate, and trying to adjust timing using the adjustable plate, I find out the pickup on the new plate has a completely different resistance value and is throwing timing ALL out of whack.
So back to original pickup on stock plate with Amazon stator coils. Fires up, but only after many kicks and bogs like a madman outside of idle.
Side note at this point, the threads for the flywheel on the crank are shot so I'm running the nut without washer just to get 4 threads or so onto the nut. I really don't want to split the case to replace the crank....
So I checked compression and found I was around 80 PSI, so off to the Amazon jug and piston store I went thinking this was a compression issue.
One new cylinder and piston later and I have discovered I've got a Vitos +3MM Stroker crank, so I reused the spacer plate with two new gaskets.
While in there, I replaced the reeds, which weren't actually in terrible condition.
I also bought a set of main jets because I wasn't sure what was in there (since the P.O. "just swapped out the carb") and wanted to make sure I wasn't running lean on a new cylinder and piston. Main jet is now a 270. The one that came out looked like it was well under #200.... I am skeptical as to whether or not the pilot jet is the correct size now at this point, but haven't checked....
Built a pressure tester, because they are apparently incredibly important for 2-strokes (especially our blasters) and made sure it held 7PSI for a good 5 minutes or so. Much to my chagrin, it took me a couple of days to figure out it was leaking from the tester and not the motor.....
So now, I have around 150PSI compression, it fires on the first or second kick, idles like a champ, but BOGS with any amount of throttle. LOTS of blue smoke out the back. It also kind of sounds like it's not firing every compression stroke. I have a tiny blue spark that you can hear and see when you crank it with the plug against the case.
I'm starting to think the el-cheapo coils are a terrible idea and I should be looking for OEM replacements or at the very least, the moose kit. The Ignition coil and plug boot only fit the plug if I remove the tip. The one I pulled off the blaster fit the whole tip of the plug.
Unfortunately, the only two parts I didn't save in this whole process were the original charge coil and ignition coil and those are the only two things that could be effecting this mess to the best of my knowledge.
Somewhere in here, I also balked at how much the clutch had been futzed with to compensate for not having the steel ball in between the two rods. I've since replaced the clutch, the steel ball (or added rather) and the outer rod as I couldn't get the inner rod to slide out. Now the clutch is properly aligned and engages/disengages correctly without bending the bracket on the block and adding a bunch of washers (as it had when I originally purchased it).
This little blasty has been awesome so far and I really wanna ride it!
Here is a video of how it runs now.
Here is a video of the spark across the gap @ .030 ± .002. It's in slow mo!
I don't want to spend 150+ on a used OEM eBay stator, may I use the Moose Kit from MotoSport?
Any other thoughts or comments would be greatly appreciated.
