Building My CR250 Engine!

well guys it is finally time to bolt up the cr250 cylinder on to the bottom end now I've been waiting forever to do this so let's jump right into it but let me say you're gonna want to stick around for the entire video because at the end I've got a great opportunity for you guys alright let's get started so the cylinder is all ready to go got the exhaust valve all assembled and this was a cylinder that was repaired by power steel there's a big gouge in earlier so I had to fix that replayed it and weld the exhaust bridge as well so bores looking great and this thing is ready to be bolted onto the bottom end and the piston I'll be using for this build is a stock size vertex take a look at what we got here inside the box I've got the Rings this is a dual ring piston about the circlips as well now the needle bearing a piston pender right here so piston looks great I'm gonna get it ready to slide on the rod by installing the piston rings and one of the piston pins or clips as you can see this is a dual ring piston so I'll be installing the bottom ring first followed with the top and the Rings look like they're identical from top to bottom and they're marked right here with a tee so any markings should be facing up and on 2-stroke pistons they make it pretty simple there's a pin where the ring and gap lines up actually before I slide the rings onto the piston I'm gonna set the ring end gap here with the cylinder so how this works is I'm gonna slide the Rings into the bore and measure the end gap here on the ring so according to the vertex instructions on a two-stroke engines there should be a minimum ring end gap of six to nine thousandths per inch of bore so the bore on this cylinder is C two point six inches so I'm gonna gonna go to point six times the spec right here and after a little bit of math the minimum ring end gap should be sixteen to twenty three thousand seven inch so now I'm just gonna compress the ring with my finger and slide it into the bore here I'm just gonna work it down inside the cylinder a little bit about half an inch down it's gonna make sure it's even all the way around that way I'm getting an accurate measurement looks pretty good so now I'm going to measure this little gap here at the end of the Rings with a set of feeler gauges and once again our spec was from 16 to 23 thousandths so I'm gonna find a sixteenth out here right there and see if that fits into the gap yep so that fits in there pretty good but there's still a little bit of movement so I'm gonna bump up on the feeler gauge size and find out what the actual measurement there is let's go ahead and try 20,000 there there's a little bit of drag or it's catching on the ring so that is the gap right there so that definitely falls within the sixteen to twenty three thousand two that we had earlier and just to be a hundred percent sure I'm gonna go ahead and measure the other piston ring as well so this ring has the same exact measurement so we're good to go next up is gonna be putting the rings on to the piston all right let's actually start assembling stuff except it's just talking about it so I'm gonna lube up the piston here with some maxima assembly lube this is just gonna help slide the Rings into place just a light coat here on the top of the piston will do so like I said earlier these two rings are identical and there's a t mark on the top of them so that T should be facing up so I'm just gonna locate the ring end gap pin here on the bottom groove it's right there so I'm going to line up the end gap with the ring expand it and slide it over the piston and then for the top ring it's gonna do the same thing line up the end gap with a pin spam the ring over the piston so right now it looks like the rings are super loose on the piston like they're almost too big or something but once I compress them and slide them into the cylinder they'll be fine and then the last thing to do here is to install one of the piston pincer clips so what I like to do is there's a little cutout here in the piston so I'm gonna line one end of circlip up with that cutout should be able to push that circlip right down inside the piston and sometimes it helps to have a little flat blade screwdriver to push that circlip down into the piston so the circlip went a little bit deep inside the piston just gonna push it through into the groove from the other side there we go it's in there and looking good and sometimes when you're installing the circlips the end of a circle it can scratch up the piston here just like a light little little burr there so what I'm gonna do is take a file and lightly just smooth that out nothing major but definitely want to make sure there's no burrs coming off of that so that feels pretty good right there and of course you want to make sure there's no filings left over here so the piston is all ready to go but one thing I forgot about are the cylinder studs so I'm gonna thread these things in right now and so since these studs are prone to seizing over time I'm gonna put some anti-seize here on the threads and by the way there are two sides of these studs there's a rounded face and a flat base so the rounded side faces up so how I'm going to tighten down these studs is by using two nuts and locking them against each other it's gonna thread the first nut on upside-down like that leaving a good chunk of the threads exposed for the top nut and now I'm just gonna tighten these two nuts against each other and that will allow me to thread the stud into the case and these studs only need to be torqued to 12 foot pounds whenever you're working on the bottom end that's assembled like this one you want to have a rag covering up the crankshaft area here definitely don't want to be dropping a nut or like when we're putting the piston pincer clips in definitely don't want to drop something down there like that all right let's get this piston installed finally so most Pistons are gonna have an arrow like this one right here on the dome and that should always be facing towards the exhaust port or exhaust side of the engine so this piston will be installed just like that so when looking at the exhaust side of the piston here you'll notice that there aren't any lubrication or cooling holes drilled and so this vertex piston is a cast piston and those holes are not necessary on a cast piston however pistons like a forged Weiss Co will need those holes drilled and the reason for drilling holes on a forged piston and not a cast one is because cast pistons and forged pistons expand at different rates so the first step in installing the piston is to install the needle bearing for the piston pin so I'm just lube it up the inside of the rod here and then I'm gonna slide through the wrist pin bearing you definitely want this bearing lubed up pretty well just want to give everything a nice coat of lubricant before it goes together and like I mentioned earlier this arrow right here needs the point towards the exhaust side of the engine just slide on the piston just like so and since I have the circlip installed on this side of the piston the wrist pin will need to go through the other side just gotta wiggle the piston around a little bit and the pin should slide through there we go and so the last thing to do here is to install the other circlip here into the piston so once again I'm gonna put one end into a cutout here on the piston and try to work the circlip in without scratching the piston there we go popped right into the groove and this is more personal preference anything but I like to have the ends of the circlip lined up with a cutout here on the piston that way there's no possible way that circlip can come out so before I slide on the cylinder got the gasket to install and the two dowel pins so I believe the dowel pins go see you look at the bottom the cylinder here they go on the left side so on these two studs here and not a bad idea to put some anti-seize on the dowel pins either and like always I like to put a thin layer of grease on the gasket surface this just keeps the gasket into place and then if I have to pull the cylinder off or any any reason down the road the gasket will stay in one piece and it won't tear so you can see that grease holds the gasket into place pretty good and prevents it from shifting around before I get that cylinder on so at this point it is time to finally slide the cylinder on I am super excited and of course before I slide this piston into the cylinder doesn't want to have a nice coat of lube here on the skirts and inside the cylinder board as well and so how this is gonna work is I'm gonna line up the Rings with the pins as best I can try to get them centered here on the locating pin and obviously the first string is going to go into the cylinder first so I'm going to compress that just with my hands here my fingers I'm gonna try to get the cylinder square on the cases here do my best to compress that ring and if you have an extra set of hands here if you have a buddy to help you out that helps out with quite a bit trying to get these rings into the cylinder so ring number one is in and now ring number two gonna do my best don't line this one up with a pin as well looks pretty good slide down the cylinder a little bit more see if I can get that second ring started inside the bore just a light little wiggle get that thing started and now at this point got the ring started inside the cylinder just gonna do my best to keep the cylinder square with the cases and just squeeze that piston down inside of there just slow and steady gonna get it lined up with the studs here and once I'm on the studs it should have no problem with lining anything got it'll to slip right down just like that man that is looking fresh I love how the cylinder looks at the cases super happy with how that turned out so you guys saw how easy it was to slide the cylinder onto the studs here so having new dowel pins here inside these studs helps out so much and then having anti-seize or grease on them - that just makes everything slide together so much easier and then down the road so they have to pull this top end off to rebuild it the cylinder is just gonna slide right off without any issue like I won't have any problems with those dowel pins corroding or rusting now we just got to locate my nuts for the cylinder that is and I should have this thing all torque down now the cellar-door nuts call 429 foot-pounds so once I torque those in a crisscross pattern I've got a little surprise for you guys so hang tight so of course next up is gonna be the cylinder head and let me show you guys what I'm working with here this thing is so trick it is made by Fathead racing I cannot wait to put it on alright so here's the deal with these heads the biggest benefit is that they have interchangeable domes which allow you to change the compression ratio of the bike which will obviously change the power so I've got two different domes here this one is pretty close to stock compression ratio and then this one bumps up the ratio a little bit so once I have this bike running I'm gonna test out these different domes and see which one I like and then also what's cool about these heads is they improve cooling so check out all these ports here keep your bike cool and on top of all that these things just looked Rick can't wait to mount it up so like I mentioned earlier these heads are made by Fathead racing and what was really cool them to do is they donated one of these heads to me to raffle off for my cancer recovery fund so how this is gonna work is they've got a variety of heads over there on the website from different bike sizes different manufacturers and so when you enter the running for the head or for the raffle you're gonna be able to choose which head you want so you can enter or you can buy it as many raffle tickets as you want each one is one dollar and this raffle is going to end this Saturday September 15th at midnight so get your ticket spot before then and as soon as this video ends what I want you guys to do is head over to that head racing comm ph8 e ray Singh Kham and check out what they've got and so while we're on the subject of cancer treatment and cancer recovery I figured I'd give you guys a little update so I've been through two chemotherapy treatments so far and they say I've got like four to six more so that's like six more months of chemotherapy and just to give you guys a little idea of how much that costs it's like ten grand a month for treatment pretty crazy so of course I'm trying alternative treatments doing whatever I can on my own to get better you know kick cancers ass and get through this but it's like a constant roller coaster every time I go in for treatment they knock me back down to ground zero to build myself back up to like where I'm at right now you know I have decent energy I'm able to work on the t-50 a little bit and then when I go back in for treatment like on this Monday they're going to just knock me completely out again and so it's pretty tough to go through but overall it's going pretty good so I appreciate your guys's support I wouldn't be able to get through this without you and let's just keep on truckin let's kick cancers ass all right enough BS let's get this head mounted up on the engine so fat head supplied some earrings for the dome in the head so when we get these into place and mount up ahead so this style of head uses odin's instead of the traditional style metal gasket and so I'll be going with the stock compression ratio dome just to limit any issues from the get-go and then it looks like Fathead supplied new nuts and washers for the head as well and then for the cylinder just gonna wipe this down with acetone make sure there's no oil or assembly left over this is one gasket surface you don't want to have any grease or oil on that's for sure oh and one more thing before I put the head on I'm gonna make sure the engine turns over without any issues just seeing if that piston goes up and down in the bore without catching on anything Oh looks good so we're ready to go and on goes the head finally sweet that looks good now it's very important that the head nuts get torqued in an even pattern and the torque spec for this head is 20 foot-pounds so at first I'm going to tighten all these the 10 foot pounds and I'm just gonna go in a crisscross pattern here so much like tightening a wheel on a car now I'm going to bump it up to 15 foot-pounds and follow the same pattern and then up to 20 and boom just like that the motor is now finished up such a good feeling always a good idea to pop in the spark plug just trying to keep anything from entering the engine alright guys that is gonna wrap up the cr250 engine bill so as you can imagine the upcoming videos are gonna be of assembling the bike and you definitely do not want to miss out on that so if you're not already subscribed go down below right now and hit that subscribe button I just want to give a big thank you to the companies I've been helping out Flathead racing provided the head power steel USA did the cylinder repair and then vertex racing provided the piston so huge shout out to those companies and a big thank you to you guys for following along with this project and giving me all the motivation in the world to finish this bike oh and for those of you asking about the camp strong hats they are now available over on primum XCOM with that being said keep it prime guys

Channel: Cameron Niemela

Views: 542,863

Rating: 4.8846474 out of 5

Keywords: How To, Honda, CR250, Honda CR250, Dirt Bike, Motorcycle, 2 Stroke, Two Stroke, Dirt Bike Build, Fixing Motorcycle, Cameron Niemela, Niemela, Motocross, 250 2 Stroke, CR250 Project, 2003 CR250, CR250 Rebuild, Dirt Bike Project, Fixing CR250, Dirt Bike Repair, Motorcycle Repair, 2 Stroke Project, Building My CR250 Engine, CR250 Engine, CR250 Motor, 2 Stroke Engine Build, 2 Stroke Engine, 2 Stroke Motor, Engine Build, Motor Build, 2 Stroke Top End, Top End Rebuild, Rebuild

Id: kcTMZPhVn0k

Length: 19min 10sec (1150 seconds)

Published: Sun Sep 09 2018