A Problem With My CR250 Engine Build!

what up everyone it is the day we've all been waiting for time to start putting the cr250 engine back together you guys know how excited I am so I'm not gonna waste any time just gonna jump headfirst right into this project step one is the press these bearings and seals into the crank cases all of these bearings and seals were part of an engine rebuild kit that rent rabbits sent over so big thank you to those guys an easy way to pop the bearings into the crank cases is first gonna be to cool down the bearings in a freezer for a few hours or even overnight and then you want to heat up the cases either in an oven or a barbecue grill you want to heat up the entire crank case and not just the area around where that bearing sits that could warp the crank case so how this works is when things are cooled down they'll contract or shrink and then when things are heated up they'll expand so that will allow the bearings is slide into the crank cases that much easier and if we need any extra help we'll be using a hydraulic press here to heat up the crank cases I'll be using this oven that I use for powder coating as well I wouldn't recommend using your household oven that you're gonna be cooking food in there could be some contaminants coming from the crank case so I would rather just play it safe you could also use a barbecue grill like I mentioned earlier so I've got the oven heated up to 250 I'm just gonna run the crank case through there for 30 minutes and it should be ready to go also got some tinfoil laid down to protect the crank case too and then to pull the case out of the oven of course you're gonna want to wear a thick set of gloves here because it's gonna be pretty hot I'll just be using a set of worn-out scotch-brite pads I use that stuff for everything and as soon as you pull the case out of the oven and the bearings out of the freezer you gotta pop those bearings into place right away can't let things cool off or heat up so the bearing should slide right into the crank case without any hammering required I'm gonna start with the main bearing here so it shouldn't matter which way the bearings go in but the old bearings came out with the writing on the inside the crank case here so I'm gonna install it the same way and one thing I've heard about but I haven't tried is to cool off the bearing even more people have been using a electronics duster so it's like compressed gas so you flip over the can and spray the bearing with the can and that should cool down the bearing even more before dropping it right into the crankcase so I'm gonna give that a shot right now so I've got the bearing in about 90% of the way and I really don't want to hammer on it so I'm gonna use the press to push it in the rest of the way so whenever you're installing a bearing you always want to push on the outside race of the bearing not the inner race and I've actually got this part from a crankshaft installer tool that I'll be using later on in the video and it fits perfectly on top the bearing here so this will work great to press that bearing in the rest of the way just gonna line everything up here on the press should be good to start pumping it down ideally you shouldn't need to use the press to push in the bearings but this one it went in most of the way and it didn't really take a whole lot of force to get it seated so wasn't that big of an issue but for the rest of them I'm hoping they go in without any problems at all once again just gonna slide in these bearings with the lettering facing out towards the inside of the crankcase one thing to keep in mind if you have a bearing that uses a retaining clip like this one right here then there's gonna be a lip on the bearing here and you want that lip facing out towards the retaining clip with this bearing the lettering is actually facing the opposite way of what it should be installed so that could throw you off but you definitely want to make 100% sure that the lip is facing the correct way the bearings on this side went in pretty good for the most part but on the right case I'm gonna heat it up to 350 instead just get it a little bit warmer one thing I've heard that works pretty good too is using dry ice to cool down the bearings that'll get them a lot colder than the freezer would but unfortunately I don't have any dry ice on hand at the moment as you can imagine when you have something steel in the freezer and you pull it out and heat it up it's gonna have some condensation so I'm gonna squirt down these bearings with some maxima and ppl to prevent them from rusting the bearings on this case definitely went in a lot easier so I have the case in the oven at 350 for 30 minutes and then hose down the bearings with the air duster upside down to cool down the bearings of amore and that seemed to be the ticket the bearings just slid right into place now I've got some bearing retainers and some seals to install so this stuff is pretty straightforward definitely want to use some assembly Lube for the seals I'll be using maximum assembly Lube for that and for the bearing retainer bolts definitely want to throw some Loctite on those threads for the crank seals I'm just pressing them in by hand and tell their about level with a case surface then I'm using a socket or something like this to push the seal in all the way until it's flat with a case and you definitely want to make sure it's 100% level you don't want it cock to the side at all actually I was watching some older video of when I popped these old seals out and it looks like the previous seal was actually in a little bit farther so I'm just gonna press this seal in just a tad bit more to match at this point I've got all the bearings and seals taken care of if it's time to start filling up these cases the first step is gonna be pressing this Hot Rods crank into the right crank case so for the most part it's pretty safe pressing the crank into the main bearing without using any heat or cooling techniques however I'm gonna apply a little bit of heat to help things out so I can either heat up the main bearing or cool down the crankshaft and it's usually not a good idea to heat up the main bearing especially with a seal on the other side but what I've got here is a little safer method I've got a socket that fits somewhat tight inside the bearing it's the closest one I could find so I'm gonna heat up the socket slide it in and that will warm up the inside race of the bearing and allow the crankshaft to slide in a little bit easier that actually worked out a lot better than I was thinking so I wanted the need to use the crankshaft puller kind of a bummer haven't even got to try the thing out yet one thing I didn't mention is it's a good idea to put some premix or assembly Lube into that main bearing before you slide the crank in so far the hot rods crank and the bearings and seals have all checked out fine everything has gone together pretty smoothly and now this is really what I've been looking forward to getting this thing up on the engine stand and starting the building process so basically I'm just gonna slide these studs through the engine mounting holes and fasten it to the stand using the wing nuts so now I've got the crankcase secured in a stand just gonna test this thing out and figure out what position I want to work in probably right about there or even flat I think this would be a little better position that way have a better angle of a slide in the transmission shafts ship drum shift forks and all that jazz you guys have to go check out these engine stands made by the healer concepts coolest thing ever if you're gonna be working on the engine so they're available over at nihilo concepts com I'll also put the link down below before we get started with assembling the transmission I'm gonna squirt some assembly Lube into these bearings and the purpose of this is to prevent damage when the engine is first started up so when you build an engine and you add in oil the oil is not going to be completely circulated throughout the engine until a few seconds after the initial startup so that's where the assembly Lube comes into place it'll protect those bearings and surfaces that may not have oil in them at the initial startup as you can see there is a lot of parts to the transmission so you want to make sure you've got everything there before you start the assembly process so what you can do is head over to an OEM parts supplier like Rocky Mountain for example pull up their fish or the parse diagram print out the diagram for the transmission or the shifting components and you'll have everything there to check over to make sure you've got all the washers pins spacers gears all that I might as well just show you guys firsthand so I'm over on rocky mountains website and I'm gonna pull up om parts right here I've already got motorcycle 2003 which is the year of this bike all that selected I'm just gonna find cr250 and then pull up the transmission diagram gonna be down here at the bottom so it's got a nice breakdown of all the gears shafts spacers washers and all that thatwe can check over everything on the transmission make sure it's all there and by the way if you guys are in need of parts definitely check out Rocky Mountain atv/mc they've got everything you'd ever need om or aftermarket so I'm just gonna print out this diagram here and I should be in business alright I'm gonna give you a little demonstration of how it would check over each transmission shaft so we've got the main shaft here and it's all broken down here on the diagram at the very end is a washer which you can see is on there and then a gear you got a gear here then another washer in between gonna pull that apart yep there is a washer in there and then a gear after that and then a bushing of some sort and then a washer or two washers and kind of see oh that's actually a clip yeah that's the circlip in there so you can kind of pull things apart take a look at it make sure it's all there and then a another gear you're at the end and then in between is another let's see that looks like a circlet and then a splined washer as well follow it up with a gear so I mean you could pull it all apart check it all out make sure it's all there because having all those washers and all those clips in there is pretty critical but definitely doesn't hurt to go through and check it all while you have the engine completely apart so the assembly process is up next some of you guys might notice that this transmission looks a little bit different so it's actually been polished out using a process called isotropic finishing so this is gonna make the transmission work a whole lot smoother and there's many other benefits too so if you guys are interested in getting your transmission done definitely go check out trick engineering we'll get you all set up alright enough talking let's start putting things together so the transmission gears to line them up you just mesh these gears together well so you can see they all line up and they're gonna slide the shafts through the bearings in the crankcase I think it's gonna be easier to have the crankcase more upright when you're sliding in the transmission shafts that way you don't have to hold the washers into place and the gears don't start sliding on the shaft give this a shot here so next up is installing the shift Forks and the shift drum so I prefer to go piece by piece with this stuff I know some people like to line up the transmission shafts with the forks and the drum and slide it in as a set but I just like to go piece by piece to make sure everything is together correctly there really is no perfect way to do it so for this step it's gonna be easiest with the engine laying flat that way we can get at these transfer gears here and slide the shift Forks into that position all right we've got a shift fork set with two on the pin and then this one just has one so we're gonna take a look at these transmission shafts and the main shaft just has one spot for a shift work while the counter shaft has two one at the bottom and one farther up so of course the pin with two forks is gonna go on to the counter shaft so it's really not too complicated the fork just slides right into that little slot I might have to pull up on the gear to get it in widened in just like that and the pin is gonna face towards where the drum sits we're just gonna leave the pin out of the equation for now that goes in a little bit later so we've got to shift Forks here for the counter shaft in there March WL and for our so there's a right in the left here the right is gonna go on the clutch side of the engine and the left is gonna go on the flywheel side so the right is gonna be at the bottom pop this into place here and then the left side is going up top and finally time to put the shift drum into position so basically they're just gonna push the shift Forks out of the way a little bit make room for the drum and it just slides face down into that bearing make sure you get it seated all the way now to get the shift Forks into the drum they just pop right into those little grooves there so once again you might have to pull up on the gear farther down like that to get it to pop into place and then the shift pen will slide right through those Forks to lock this whole setup into place you got to make sure that pin goes in all the way and it's gonna be the same deal on this side as well it's got a pull up on the gear get that pin in and then slide the retaining pin through the fork just like that pretty simple now that I've got everything within the cases together just gonna spin the gears and make sure they work smoothly with each other Matt you can already tell a difference with the isotropic finishing the gears just spin flawlessly and to go through the gears basically how this works is when you shift the transmission the shift drum spins and therefore moves the forks on the shafts so I'll give you a little demonstration here you got to have the shaft spinning for it to be able to shift as you can see as I'm spinning the transmission and shift drum simultaneously it's moving the gears on the shaft and that's what's engaging the different gears on the transmission so people make it out to seem like rebuilding a transmission or a bottom end it's a lot of work and it's super complicated but in all honesty it really is not I mean it looks like there's a lot of gears and a lot of parts here but once you take your time and you follow a service manual or a video like this it really isn't too bad anyone can do it so what we've got up next is installing the dowel pins the center case gasket these are the dowel pins right here and there's also an opening that goes up front once we have all that in place the left case will be ready to go on for the Dell pens I would definitely recommend putting some anti-seize lubricant on them they are the most common thing that rust or seized up on an engine especially the front one up here that one always gets a bunch of water in there and it rusts and it's really hard to split the cases at that point it's gonna apply a light coat of anti-seize to each dowel pin here and before I slide this over Inge and the gasket on I'm gonna put a little layer of grease on the entire gasket surface so what this does is it helps keep the gasket into place during the assembly and then if anything happens like I need to pull the crankcase back apart the gasket will not be stuck and it won't rip as easily when I split those cases back apart so you just never know when you'll have to pull those cases back apart during the assembly process and the grease I'll be using is just this general Maxima waterproof grease so it doesn't really take much of a layer on there just a light dab around the whole thing so this piece up here is just to keep the whole gasket together we'll be cutting it at a later point but right now I'm just gonna cut it in half so that way it's not holding up this part up top here so now I can get that gasket all the way down onto the case so what I'm doing here is just making sure all the holes line up kind of tacking it down to grease and one last thing I'll do here before I slide the left case on is squirt some assembly lube on to the transmission gears and some of shifting components to try to get it on every gear set and then get it inside of each one of these shift drum grooves and then go through the gears to get that assembly Lube spread around now there's a few things I need to do this left case to get it ready to install on the engine it's gonna squirt some assembly Lube into the bearings grease up the gasket surface and then once again I'm gonna heat up the socket so that way I can warm up the inner race of the bearing and that'll allow the crank to slide right through now a left case should just slip right on but I gotta be quick about this before that bearing cools down okay I kind of lied here the left case isn't sliding on like I'd hoped so I'm gonna have to bust out the Tusk crankshaft puller tool this is gonna thread onto the end the crank and pull the crank into the left crank case or push the left case down onto the crank whatever way you want to call it so first we've got the adapter for the puller and then a nut that threads onto the end the crank read this all the way down and here's the puller shaft reading onto the crank then we've got the polar body here just slides over the whole thing there we go so ideally you'd like to have these bars underneath the puller that way you have a nice flat surface to get leverage on but from the looks of it not gonna have enough thread here so I'm just gonna have to go directly onto the crank case like that should still work out just fine this should be pretty self-explanatory now as I tightened down this nut it's gonna pull up on the shaft which is connected to the crank shaft and push down on the crank case at the same time so it's gonna bring this whole unit together all right time to get polling on this crank as I'm tightening those nut I got to make 100% sure that this thing is going on straight every couple seconds I'm just gonna check the dowel pins make sure they're lining up and all the pins and shafts as well looks like everything is lining up so far just gonna continue crank it on this thing got everything pressed together seems like everything lined up really well so first time using this tool and I'm pretty impressed seems like it worked pretty well once again this is a tusk crankshaft puller tool and they're available over at Rocky Mountain I'll put the link down below to where you can pick one up super handy tool to have definitely save the day on this build alright the cases are finely pressed together I'm gonna rearrange the engine here on the stand and then start popping in all these case bolts now for the case bolts I'm gonna get them all started into the threads before I start tightening things down sometimes they'll get hung up on the gasket and you kind of have to shift things around to get them to line up so it's a bit of a guessing game when you're putting these bolts in you want about 3/8 to 1/2 inch here before you start threading the bolt in the case so that one looks about right let's find one little lower hole yep that's the correct one now it's pretty important to try to tighten these down evenly so I'll go up to the top give it a little tighten come down to a bottom bolt give that a little bit of torque it's kind of work my way around in a even pattern here the torque on these case bolts is only going to be about 6 or 7 foot-pounds so if you have a quality torque wrench that you can trust go that route or you can just tighten by hand that's what I'll be doing here if you're gonna be tightening these bolts by hand try to fall on the side of caution because they do strip out pretty easily of course you want them tight but try to be really careful with them and while I'm at it I'm gonna go ahead and install the drain plug with a new crush washer now that we've got everything together and tighten down just gonna go through and make sure everything spins without any major hesitation crank feels pretty good transmission as well I'm gonna install the piece on the end of the shift drum so that way you can go through the gears make sure everything is functioning properly you definitely don't want to forget this little pin that goes on the end of the shift drum it's gonna go ahead and torque this bolt to 16 foot-pounds and then I'll be ready to go through the gears and make sure they're all good so just like before as I'm spinning the transmission shafts I am going to spin the shift drum as well all right I've got some bad news guys so when they had the cases together I noticed there was a little too much side-to-side play in the counter shaft within the cases and things just didn't feel right and it wouldn't shift in the neutral so I pulled things apart you can see I've got the cases split again and I dug into this counter shaft so underneath this top gear there's supposed to be a thrust washer sitting right here and for whatever reason it wasn't in there got lost throughout the process or wasn't even in there from the first place you know maybe someone tore into this engine before and never put it in but regardless I've got to order a new one not a big deal you know be it a couple extra days to get this thing together but those are just the type of things you run into you during an engine build so it's not always gonna be sunshine and roses with this stuff sometimes a little $3.00 washer will hold things up you just never know it is part of the deal I'm gonna show you guys why that little thrust washer is so important to sly this gear back on so I've got it in first gear everything seems to be spinning fine and then it'll come to a stop right there it starts binding up so if you pull up the gear to simulate that little washer in there everything spins together just fine there's no binding at all so I'm gonna pull this back apart and show you the little gap there where that washer should be just gonna put the collar and the top washer into place so you see that little amount of play there where that washer should be that makes a world the difference in how the transmission spins and chips it's crazy here's the thing to take away from this if you're putting things together and you notice something isn't quite right or there's any question whatsoever don't hesitate to pull things back apart and double check I mean I would hate to get this thing together and realize it doesn't shift into neutral and the transmission is binding up so always double-check your work especially when it comes to the transmission I mean that would be a nightmare to pull this whole bike back apart just for a stupid little washer all right guys I'm gonna go order that little washer and there's actually a few other things I need to order up as well and as soon as that stuff comes in the next video will be on putting this thing back together and getting the whole bottom end in one piece so that will include the clutch shifting components violins theater and some other parts and pieces as well so stay tuned for that video so you guys enjoy this one go smash that like button it really helps me to continue to do these videos well I'll see you all in the next one

Channel: Cameron Niemela

Views: 744,454

Rating: 4.8562107 out of 5

Keywords: Honda, CR250, Honda CR250, Motorcycle, 2 Stroke, Two Stroke, Dirt Bike Build, Fixing Dirt Bike, Fixing Motorcycle, Two Stroke Build, Broken Dirt Bike, CR250 Build, CR250 Two Stroke, Cameron Niemela, Niemela, Motocross, 250 2 Stroke, Project Bike, CR250 Project, Fixing CR250, 2003 CR250, How To, MX, CR250 Engine Build, Engine Build, Two Stroke Engine Build, Two Stroke Engine, Engine Rebuild, CR250 Engine Rebuild, Two Stroke Rebuild, Problem With My CR250 Engine Build

Id: afx7c3wLF0o

Length: 28min 50sec (1730 seconds)

Published: Fri Jun 01 2018