Ok I sat staring for 2hrs at my motor wondering how to re-install a new shift cam, any help would be appreciated
Shift Cam
- Thread starter EvilElvis
- Start date
Is it the kind with the screw in the middle or is the new one a weld on one? If it's weld on, the cases have to be split and the shift drum has to be replaced.
Ok, I have a really good writeup saved but it won't let me enter it for some reason. I'm just testing this now... it keeps saying HTTP 500 internal server error when I hit save.
This isn't the first time the "ask a pro" section has done this to me... it'll let me type a short message but a long write-up it will error out.
I have managed to paste it into several smaller posts and eliminate the words which apparently were messing it up. Beginning a paragraph with "install" or "drop" apparently will screw something up
This isn't the first time the "ask a pro" section has done this to me... it'll let me type a short message but a long write-up it will error out.
I have managed to paste it into several smaller posts and eliminate the words which apparently were messing it up. Beginning a paragraph with "install" or "drop" apparently will screw something up
Last edited:
Ahhh the finer points of putting a blaster transmission back in..... I can tell you now, this is a sticky-able topic!
So here's the do-it-yourself version!
The first thing you will need is a table with a slit down the middle of it long ways. I know, workbenches usually don't have that but in this case, you'll understand why. I bought a "wood working bench" at big lots for $8 (maybe?) It's two pieces of wood with little peg holes and the two pieces of wood have a screw between them so the two halves of the table top can act like clamps by installing pegs in the peg holes and screwing the two table halves together to clamp your work. I left it out in the rain one night and the pressboard halves crumbled so I put two pieces of "5 by" treated deck cladding on the "clamps" as my table top. Has served me VERY well since than and makes putting a blasty bottom end together a SNAP. If you don't have a table like this and don't feel like buying one, an old milk crate work fairly well and even a thick sides carbboard box sitting on a work bench works sometimes...basically anything that can support the cases laying on their side while you install shafts that hang through the cases (and would not be able to installed that way with the case half laying flat on a countertop).
So here's the do-it-yourself version!
The first thing you will need is a table with a slit down the middle of it long ways. I know, workbenches usually don't have that but in this case, you'll understand why. I bought a "wood working bench" at big lots for $8 (maybe?) It's two pieces of wood with little peg holes and the two pieces of wood have a screw between them so the two halves of the table top can act like clamps by installing pegs in the peg holes and screwing the two table halves together to clamp your work. I left it out in the rain one night and the pressboard halves crumbled so I put two pieces of "5 by" treated deck cladding on the "clamps" as my table top. Has served me VERY well since than and makes putting a blasty bottom end together a SNAP. If you don't have a table like this and don't feel like buying one, an old milk crate work fairly well and even a thick sides carbboard box sitting on a work bench works sometimes...basically anything that can support the cases laying on their side while you install shafts that hang through the cases (and would not be able to installed that way with the case half laying flat on a countertop).
Alright, first count your pieces and inspect them thoroughly. Shift forks shouldn't have abnormal amounts of wear on them, the shift forks guide shafts shouldn't be bent or boogered, and the drum "channels" shouldn't be worn out.
There are three shift shafts and all three are different and not interchangable but there's an easy way to tell them apart and their proper location. Two of the shift forks are "long" and they go on the counter , or output, shaft. The short one of the bunch goes in the input shaft. One of the two long ones is angled a LOT and the other, the forks come straight off the front. If your left case half is laying on the table and you're installing parts from the top (which is the easiest and most likely way you'll end up doing it) the "bent" or angled one goes in the bottom (or far left up against the chain side if the engine is sitting in the quad) with the angled part sitting towards the chain.
So you're sitting there with the left side case down on a table, perhaps a crank stuck in it, and a transmission laying there pieces scattered all over the table... Sounds about the right starting point?
You're gonna want to remove a few things right now if you didn't before... the shift star alignment roller needs to be removed from the right side right now. If you don't it will cause you to break something or pull your hair out later... You're gonna want to put a few things in if they're not already.... the crankshaft needs to be pulled up tight against the stator side bearing and the rod needs to be sticking out of the "top" of the engine (or the hole where it's supposed to sticking out of before you put the top end on). You can go ahead and install the balancer shaft with the threaded end up.
You can go ahead and install the two transmission shafts. They need to be mated before installation because you can't get one in if the other in already installed. Yamaha recommends putting an o-ring in the groove in the output shaft that the sprocket lock washer sits in but in my experience, that groove won't catch the seal lip as long as you're careful during installation and lube the lip and shaft (haha).
So now you have the crank, balancer and both shafts sitting there looking up at you. The shafts shouldn't turn freely at this point because the drive dogs have the transmission in like 3 different gears (so don't panic right now).
There are three shift shafts and all three are different and not interchangable but there's an easy way to tell them apart and their proper location. Two of the shift forks are "long" and they go on the counter , or output, shaft. The short one of the bunch goes in the input shaft. One of the two long ones is angled a LOT and the other, the forks come straight off the front. If your left case half is laying on the table and you're installing parts from the top (which is the easiest and most likely way you'll end up doing it) the "bent" or angled one goes in the bottom (or far left up against the chain side if the engine is sitting in the quad) with the angled part sitting towards the chain.
So you're sitting there with the left side case down on a table, perhaps a crank stuck in it, and a transmission laying there pieces scattered all over the table... Sounds about the right starting point?
You're gonna want to remove a few things right now if you didn't before... the shift star alignment roller needs to be removed from the right side right now. If you don't it will cause you to break something or pull your hair out later... You're gonna want to put a few things in if they're not already.... the crankshaft needs to be pulled up tight against the stator side bearing and the rod needs to be sticking out of the "top" of the engine (or the hole where it's supposed to sticking out of before you put the top end on). You can go ahead and install the balancer shaft with the threaded end up.
You can go ahead and install the two transmission shafts. They need to be mated before installation because you can't get one in if the other in already installed. Yamaha recommends putting an o-ring in the groove in the output shaft that the sprocket lock washer sits in but in my experience, that groove won't catch the seal lip as long as you're careful during installation and lube the lip and shaft (haha).
So now you have the crank, balancer and both shafts sitting there looking up at you. The shafts shouldn't turn freely at this point because the drive dogs have the transmission in like 3 different gears (so don't panic right now).
Put the angled fork into the bottom dog groove first but kick the pin end out towards the case. Put the short fork in with it's pin end kicked out towards the case.
Then, put the shift drum into its hole and then rotate so some part of the grooves are towards the fork pins. Now carefully lift the angled fork up moving the drive dog along the counter shaft with it until its alignment pin will fit into its groove. Don't panic about which groove, the fork won't fit right into the wrong groove but for reference I believe the angled fork goes into the bottom groove, the short fork goes into the middle and the straight fork goes into the top. Rotate the pin end of the angled fork into until you can look down through the pin end of the fork and see the pin hole straight on. Lift the short fork and drive dog up until it's pin engages the drum and then rotate it's pin end in towards the drum. Now install the straight fork into it's drive dog and rotate it's pin end in towards the drum.
With the three forks in their places, the two fork shafts should slide down through the forks and into their repective holes in the case. Remember that the long shaft goes e-clip end up... the shorter shaft doesn't matter which end goes in first. Now, you should be looking at your bottom end with the crank, balancer shaft, two transmission shafts, three forks, shift fork pins, and shift drum sitting in there all happy and in their places. Do NOT rotate anything right now... without the skift fork pins held captive by the right side case, instead of the fork sliding along the pin, the pin can lift up out of it's hole on the left side case and fall out of the hole creating a HUGE mess of problems later.
If you lapped the cases earlier (which you should have if you pulled the crank out) make sure the right case half is clean and coat that half with sealant (grey RTV silicone or whatever your case sealant of choice is) and slide it gently over all of the shafts. The last half inch is the hardest to align and push down because the alignment pins have to be perfect and sometimes they're not perfectly round so they have to be pushed into the right side case a little bit. I have a dead blow hammer to lightly tap case halves together that are being stubborn but I do NOT recommend a hammer for someone doing this for the first time because if you're not paying attention, you could break something easily using a hammer.
Oh, make sure as you're sliding the halves together when you get close to them seating, turn the shift drum slightly to make sure the shift star points can clear the case! Otherwise the cases will never go together and you'll be standing there stratching your head wondering what's holding them apart.
The bolt tightening secquence is kinda important too.... The first screw that should be installed is the longest non-stator screw. It's the one in the very back (when the engine is in the quad) inside the stator housing. The next most important one is the short one that goes at the very top of the cases followed by the one at the bottom of the cases. Then work your way towards the end of the case jumping from the back half (transmission end) to the front (crank end) and tightening in sequence. This way, the sealant and cases are squeezed together in the middle and any misalignment between them is moved towards the outsides instead of "wrinkling" the case mating surface by forcing misalignment to the middle (kind of like doing an automobile head gasket).
Then, put the shift drum into its hole and then rotate so some part of the grooves are towards the fork pins. Now carefully lift the angled fork up moving the drive dog along the counter shaft with it until its alignment pin will fit into its groove. Don't panic about which groove, the fork won't fit right into the wrong groove but for reference I believe the angled fork goes into the bottom groove, the short fork goes into the middle and the straight fork goes into the top. Rotate the pin end of the angled fork into until you can look down through the pin end of the fork and see the pin hole straight on. Lift the short fork and drive dog up until it's pin engages the drum and then rotate it's pin end in towards the drum. Now install the straight fork into it's drive dog and rotate it's pin end in towards the drum.
With the three forks in their places, the two fork shafts should slide down through the forks and into their repective holes in the case. Remember that the long shaft goes e-clip end up... the shorter shaft doesn't matter which end goes in first. Now, you should be looking at your bottom end with the crank, balancer shaft, two transmission shafts, three forks, shift fork pins, and shift drum sitting in there all happy and in their places. Do NOT rotate anything right now... without the skift fork pins held captive by the right side case, instead of the fork sliding along the pin, the pin can lift up out of it's hole on the left side case and fall out of the hole creating a HUGE mess of problems later.
If you lapped the cases earlier (which you should have if you pulled the crank out) make sure the right case half is clean and coat that half with sealant (grey RTV silicone or whatever your case sealant of choice is) and slide it gently over all of the shafts. The last half inch is the hardest to align and push down because the alignment pins have to be perfect and sometimes they're not perfectly round so they have to be pushed into the right side case a little bit. I have a dead blow hammer to lightly tap case halves together that are being stubborn but I do NOT recommend a hammer for someone doing this for the first time because if you're not paying attention, you could break something easily using a hammer.
Oh, make sure as you're sliding the halves together when you get close to them seating, turn the shift drum slightly to make sure the shift star points can clear the case! Otherwise the cases will never go together and you'll be standing there stratching your head wondering what's holding them apart.
The bolt tightening secquence is kinda important too.... The first screw that should be installed is the longest non-stator screw. It's the one in the very back (when the engine is in the quad) inside the stator housing. The next most important one is the short one that goes at the very top of the cases followed by the one at the bottom of the cases. Then work your way towards the end of the case jumping from the back half (transmission end) to the front (crank end) and tightening in sequence. This way, the sealant and cases are squeezed together in the middle and any misalignment between them is moved towards the outsides instead of "wrinkling" the case mating surface by forcing misalignment to the middle (kind of like doing an automobile head gasket).
Last edited:
The last screws you should install are the stator mounting screws to make sure sealant isn't blocking them (but there's no need to hurry and install the flywheel and stator yet just make sure the screw holes are clear).
Now, you SHOULD have a fully functional bottom end but before you go spending a BUNCH of time putting all the rest of the stuff together only to find out later your transmission has something wrong.... TEST IT NOW! Turn the input shaft (the one the clutch basket sits over) and turn the shift drum into all of it's positions. Because you removed the spring loaded alignment roller earlier, the shift drum should turn easily at this point but alignment will be difficult... it doens't matter about alignment so much as you see the output shaft gear turn into each gear now before you finish putting the engint together. You should be able to turn the shift drum all the way to one end (all the way clockwise is 1st gear BTW) and be in first gear (output shaft turns slower than the input). Half position should be neutral and the shafts will appear to spin at the same speed but that's just gears dragging each other. If you hold the output shaft, the input shaft should be able to turn with minimal drag.
Each shift star point that comes up while turning the shift drum counterclockwise should be the next higher gear and you should see the output shaft begin to turn faster as you're turning the input shaft. You should have six different gears and then neutral between 1st and 2nd. If you don't, run through the pattern about 4 more times to confirm you actually have a problem because a problem at this point means splitting the cases again and you want to make sure you're doing that for a GOOD reason (not just because you're confused about the shifting pattern).
If you have to split the cases, wait about a half an hour for the sealant to partially cure otherwise you'll get it all over everywhere trying to remove the case half with wet sealant everywhere.
The good news about splitting cases is that the parts inside cannot be put in the wrong positions and get everything else back together. The only reason you may have to pull the cases back apart is if some part of the transmission is bent horribly and you didn't catch it earlier during the inspection process...
Now, you SHOULD have a fully functional bottom end but before you go spending a BUNCH of time putting all the rest of the stuff together only to find out later your transmission has something wrong.... TEST IT NOW! Turn the input shaft (the one the clutch basket sits over) and turn the shift drum into all of it's positions. Because you removed the spring loaded alignment roller earlier, the shift drum should turn easily at this point but alignment will be difficult... it doens't matter about alignment so much as you see the output shaft gear turn into each gear now before you finish putting the engint together. You should be able to turn the shift drum all the way to one end (all the way clockwise is 1st gear BTW) and be in first gear (output shaft turns slower than the input). Half position should be neutral and the shafts will appear to spin at the same speed but that's just gears dragging each other. If you hold the output shaft, the input shaft should be able to turn with minimal drag.
Each shift star point that comes up while turning the shift drum counterclockwise should be the next higher gear and you should see the output shaft begin to turn faster as you're turning the input shaft. You should have six different gears and then neutral between 1st and 2nd. If you don't, run through the pattern about 4 more times to confirm you actually have a problem because a problem at this point means splitting the cases again and you want to make sure you're doing that for a GOOD reason (not just because you're confused about the shifting pattern).
If you have to split the cases, wait about a half an hour for the sealant to partially cure otherwise you'll get it all over everywhere trying to remove the case half with wet sealant everywhere.
The good news about splitting cases is that the parts inside cannot be put in the wrong positions and get everything else back together. The only reason you may have to pull the cases back apart is if some part of the transmission is bent horribly and you didn't catch it earlier during the inspection process...
My cases are together that all need said MAJOR REP FOE CIVIC WEEEEEEEEEEEEEEEEEE!!!!!!!!!!!!!!!!!!!!!!!
Okay I know this thread is SUPER dead but hoping it catches someone’s eye.. so I’m reassembling my transmission and this guide was super helpful, but one part confuses me. On the output side with the long fork guide pin, does the snap ring butt up against the shift forks or the case? Seems like it’s impossible to install it with snap ring up against the case, but I have a 2nd blaster engine here that I have not disassembled the transmission in and the snap ring is up against the case with the tapered side out. So is there a way to install it with the snap ring up against the case, or is the snap ring supposed to be butted up against the shift forks with the flat side facing out? Thanks.
I’m lazy, I always follow the manual
https://www.blasterforum.com/thread...ervice-and-owner-manuals-free-download.17325/
https://www.blasterforum.com/thread...ervice-and-owner-manuals-free-download.17325/
