I did on mine. My son bought it from a cycle salvage place and knew I grew up on old DTs and gave it to me. I tore it completely down and have new bearings and seals to go back in. I'm only doing it because it's a bike I plan on keeping. All the DTs I've owned...I've NEVER had a problem with bearings. My 75 250 was prone to ignition problems with the points. (Usually dirty or wet. I kept a fingernail file with me) Also on my 75 I had 5th gear lock up and my dad split the cases to get the gear off the shaft. Other than that I rode the wheels off that bike with barely a problem. Parts were easy to find for this 78 and I figured..." Why not." If it's something you've wanted forever and DON'T want to get rid of it...that's what I'd do..full bearings and seals. The bike's more of a tractor than a high reving motocross bike. For "ME"...I'm gonna run GREAT tranny fluid in mine and I'll mix mine rich. (I bypassed the oil injector on mine) Plugs are cheaper than bearings. That's a LONG answer (actually it's just MY experience and plans) but I think you'll be good either way🤘
That looks so clean! I’ve been wanting to do a top end on my DT400 as well, I’ll be checking out Eric Gorr when the time comes. Thanks for this video. For the piston and rings, did he pick out the ones for you to buy to match the bore?
Eric was AWESOME to work with. I called him and we talked it through what I wanted done. He told me a price and I shipped it to him. Eric bored it, chamfered the ports, sized the cylinder after the bore he ordered the rings and piston for me. He sandblasted the cylinder and shipped it all right back. I will DEFINITELY use Eric in the future if I need another bore. I don't know if you watched my other videos, but this bike is going to be a vintage GNCC bike. (Or that's kinda how I'm modeling it) YOU are the FIRST to comment on my video....thought no one was going too. Keep checking back as I'm keeping updated on the project.
@@makeityourself1 sweet! That’s gonna be awesome! I’ll follow the build and see how it goes, DT400 motor is a nice torquey motor. All said and done how much was his labor on your cylinder? I know it’s 50$ for just a bore but curious for the sandblasting and porting
@@mmoutdoors1 I can't recall exactly....but it was $50 for the bore then he said to call and he'd give me the final price. So I sent $50....he got the piston and rings and I'm pretty sure both of those AND he shipped it back for no extra was right about $200-$220. I had already sent the check and he told me about the machine work he did, and as far as I know he didn't charge for the sand blasting. On his site I THINK the sand blasting and machine work is all extra. So.....maybe he was just bored, or threw those services in????? I felt good about the price though as an over sized Weisco was well over $150.
What year is your DT? Are you going all in on correct/stock? The YZ was developed from a modified DT , so that is kinda how I'm building mine. I'm just not a motocrosser, so I am going with a resto-mod GNCC feel.
@@makeityourself1 mine is a 78, so it’s got the mono shock. I plan to keep it pretty much stock. May try some different reeds and play around with jetting or other easy stuff. I mostly just cruise around my area but we go out forest road riding with them. 400 is nice cuz it can basically pull from 1000 rpm 1-4th gear going uphill haha it’s insane for a 2t
Thanks man! I grew up as well on old bikes. My first "real" bike was a DT 250, basically the same as a DT 400 in power. Both were a little sluggish. Glad to have made you happy with your childhood memories 👍
درود برشما نادر هستم از کشور ایران خاطرات جوانی من با DT 400 گذشت خوشحالم کردی ❤❤❤❤❤
hi i recently got a77 dt 400 do yourecommend doing the lower end splitting , new bearings and such
I did on mine. My son bought it from a cycle salvage place and knew I grew up on old DTs and gave it to me. I tore it completely down and have new bearings and seals to go back in. I'm only doing it because it's a bike I plan on keeping. All the DTs I've owned...I've NEVER had a problem with bearings. My 75 250 was prone to ignition problems with the points. (Usually dirty or wet. I kept a fingernail file with me) Also on my 75 I had 5th gear lock up and my dad split the cases to get the gear off the shaft. Other than that I rode the wheels off that bike with barely a problem. Parts were easy to find for this 78 and I figured..." Why not." If it's something you've wanted forever and DON'T want to get rid of it...that's what I'd do..full bearings and seals. The bike's more of a tractor than a high reving motocross bike. For "ME"...I'm gonna run GREAT tranny fluid in mine and I'll mix mine rich. (I bypassed the oil injector on mine) Plugs are cheaper than bearings. That's a LONG answer (actually it's just MY experience and plans) but I think you'll be good either way🤘
That looks so clean! I’ve been wanting to do a top end on my DT400 as well, I’ll be checking out Eric Gorr when the time comes. Thanks for this video. For the piston and rings, did he pick out the ones for you to buy to match the bore?
Eric was AWESOME to work with. I called him and we talked it through what I wanted done. He told me a price and I shipped it to him. Eric bored it, chamfered the ports, sized the cylinder after the bore he ordered the rings and piston for me. He sandblasted the cylinder and shipped it all right back. I will DEFINITELY use Eric in the future if I need another bore. I don't know if you watched my other videos, but this bike is going to be a vintage GNCC bike. (Or that's kinda how I'm modeling it) YOU are the FIRST to comment on my video....thought no one was going too. Keep checking back as I'm keeping updated on the project.
@@makeityourself1 sweet! That’s gonna be awesome! I’ll follow the build and see how it goes, DT400 motor is a nice torquey motor. All said and done how much was his labor on your cylinder? I know it’s 50$ for just a bore but curious for the sandblasting and porting
@@mmoutdoors1 I can't recall exactly....but it was $50 for the bore then he said to call and he'd give me the final price. So I sent $50....he got the piston and rings and I'm pretty sure both of those AND he shipped it back for no extra was right about $200-$220. I had already sent the check and he told me about the machine work he did, and as far as I know he didn't charge for the sand blasting. On his site I THINK the sand blasting and machine work is all extra. So.....maybe he was just bored, or threw those services in????? I felt good about the price though as an over sized Weisco was well over $150.
What year is your DT? Are you going all in on correct/stock? The YZ was developed from a modified DT , so that is kinda how I'm building mine. I'm just not a motocrosser, so I am going with a resto-mod GNCC feel.
@@makeityourself1 mine is a 78, so it’s got the mono shock. I plan to keep it pretty much stock. May try some different reeds and play around with jetting or other easy stuff. I mostly just cruise around my area but we go out forest road riding with them. 400 is nice cuz it can basically pull from 1000 rpm 1-4th gear going uphill haha it’s insane for a 2t
درود برشما نادر هستم از کشور ایران خاطرات جوانی من با DT 400 گذشت خوشحالم کردی ❤❤❤❤❤
Thanks man! I grew up as well on old bikes. My first "real" bike was a DT 250, basically the same as a DT 400 in power. Both were a little sluggish. Glad to have made you happy with your childhood memories 👍