1975 DT175B | Clean-Up

It has almost been a full year since I bought my 1975 DT175b for $500 not running but with a title and I got what I paid for… a shitty, beat enduro and I love it. Here’s the photos from when I first picked it up HERE.

It took some work to get it back on the road but I was able to do for about $200 and I made my goal of having a pit bike for Mid-Ohio which ruled. Since then, I’ve put ~400 (hard miles) on it and now it’s in need of some work to keep it running the rest of the year… and to make it better than Ed’s CT175.

As it started in May 2013. Full post HERE.


Back on the lift as it looks now. Just a little beat up.




Top end came off without any issues. I wish had a hose to wash the bike down before working on it.


The head is going to Mar Automotive to get cleaned and honed. I can’t seem to figure out what size the piston is based on the numbers and it needs to be replaced but Mar should be able to tell me what size piston I need to buy.


It looks like the timing was off at one point before I owned it since the piston shows signs of melting through a little.


My engine has always had a rattling noise that I’m going to try and fix so I’ll be going through the different tolerance checks. The crankarm free play should be between .4mm and .6mm. Mine is unfortunately measuring at .7mm but I doubt this is the cause of the knocking. I don’t plan to get that deep into splitting case and replacing washers and bearings right now since I don’t have the tools or experience of getting into that.


I mocked up a MT125 Elsinore front wheel from Chris F. I really want to run a 21 dirt wheel and this one will work with some modification and it came with a decent dirt tire. I plan to copy Dan’s brake mount solution he posted awhile ago on Greasy Gringo. That and turning a simple spacer should make the wheel work.


Next up: Engine reassembly

6 responses to “1975 DT175B | Clean-Up”

  1. ed says:

    So you’re admitting my CT1 is better… I agree with that.

  2. Mike K. says:

    the 21 up front is going to be awesome. Can’t wait for mid ohio this year! BRAAAAAP

  3. Carson says:

    The rattling noise in your motor, do you only really hear it at idle? Does it sound like ring chatter? Thats fairly common in the old bigger 2-stroke singles. Advanced timing will cause it to happen more often and louder, but a little bit of ring chatter at stock timing is alright.

  4. adam says:

    Hey Carson, good info.

    The rattling is mainly at idle so maybe it is partially ring chatter. The piston is also a lot looser in the cylinder than what I’m used to seeing with the 4 strokes so I think that is contributing to it.

  5. ed says:

    do you have any photos of your bikes? you should start a tumblr or blog…

  6. Carson says:

    Adam: The piston should be pretty tight in the cylinder, if it’s loose at all, at the least new rings, if there’s too much give, go for an OS piston and an overbore. You can find those things all day on ebay for the old 2-strokes

    Ed: yeah I’ve got tons of pictures of my bikes, been thinking about starting up another blog or tumblr. I’ll let you know what happens with that.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

From Past

Published - Nov 26, 2012

kelly to west river loop

I know this is a given for all / most of us… But there’s always going to be some random new person who just moved to philly and is looking for this loop, so here it is. It’s a good one.