Rebuilding 1978 Yamaha DT175 Forks

1978 Yamaha DT175. Doing some maintenance and replacing the fork oil seals.

[@carlosflore18]

Mine just started leaking...thanks for the video

[@KyleLewis-vq2nw]

Anyone watching this for advice the Yamaha recommended amount of oil is 155-158ml

[@jonsingle1614]

Good job on the forks....that....snorkel...strangles the amount of air the engine gets...costs you at least 5hp....airbox and piston mods can get you at least a extra 8hp...ask me

[@LondonWildman]

Love seeing these older machines! beauty bike! I've been following Kosmoto for a while now.. down the road from me a couple hours!

[@steveburgess6149]

Very helpful! Well done!

[@adamdipaolo494]

Great video! Thanks

[@bobburro3642]

Ive got a red 81 enduro great bike

[@chrisclemmensen4381]

Have you got any spares ? I'm looking for parts to do a rebuild on mine

[@keviny6200]

Thank you for the video! I have to ask, what size and brand tires are on that bike? I just got a 78 DT myself and hate the tires on it and came across this video. Looks great.

[@kosmoto]

Beauty! Just in time! I finally got my seals out with some heat the other day so I'm ready to throw the new ones in. Actually I lied, I only got one out, because the other fork has a stripped bottom bolt (thank you PO) that I need to get out first so I can separate the fork tube from the lower. It's on the fork with the studs sooo I can't get an extractor in there..thinking of using some tool putty to adhere a longer bolt to the head of the bolt that's in there. Oh dang, thanks for the tip on that breather tube man! Funnily enough I guess I haven't been running one this whole time...Could explain my jetting issues bahaha. I didn't know something was supposed to go there. Man...your seal came out so easy, what the heck! haha. My only question is...how do you know what level to fill up to? You said 5-6" for you but where does that number come from? Unless I missed something...I know the service manual specifies a volume of oil though. Speaking of service manuals, I emailed ya a couple.

[@DigitalRider]

I think I saw the measurement it in a video on youtube somewhere lol. The service manual says 146cc's of oil. It also says after after filling pump the outer tubes to distribute the oil. Measure the oil from top of the fork...the oil levels must be the same. If i remember, 146cc did not fill up the leg very much. I wanted a bit more oil also to stiffen up the fork. So long as they oil levels are the same...should be good to go.

[@Jammed_Toast]

I used some 146cc of 15W when I rebuilt mine. This job went much smoother then when I did mine. From what I remember I ended up having to make a forked tool to hold the valve in place at the bottom while I tightened the lower bolt. Huge PIA. I'm 180lbs and 15W made them a little too stiff but I've been too busy enjoying the bike to swap out the oil :D Happy trails, thanks for another great DT video!

[@blackridgeview]

How did you know what level the oil should be at?

[@stanm2.0]

Yo....I just ran across your channel and can't wait to go thru more of your content. I started with this one for a little knowledge but found a little gem. I noticed that you found a brand new OEM rear sprocket. I recently restored a 1977 YZ125D and had a really hard time finding the OEM rear sprocket (plenty of 51T around but not with the correct cut out pattern..sort of pizza slices with rounded edge cut outs) I searched almost a year before one showed up on Ebay. I was going for 100% accuracy. I was wondering where you found the rear sprocket that you got or if you have a "secret parts source" Hope to hear from you

[@DigitalRider]

I just got it from my dealership. Still have them available.

[@trebor23]

Hi Digital Rider, The fork seals in your bike look different to the ones I have ordered and received for my '78 DT175. I got: All Balls 55-104 Yamaha DT175 1978 Fork Oil Seal Kit 31x43x10. Your look deeper than 10 mm. Is that right? Thanks :)

[@maynorquevedo8832]

I just buy one and I love what you do where do you buy all the parts?

[@Alfonzo227]

Where did you source your replacement fork seals?

[@DigitalRider]

My dealership

[@rorystibbs5164]

What weight fork oil did you use

[@DigitalRider]

10. 155cc of fluid if I remember

[@lukeserio95]

Perfect. To the point and simple! Is this process the same for the 1980 175DT? I know Yamaha didn’t change their process much as far manufacture for their DT models but thought I’d just ask anyway. Will use this video for reference, thank you!