I've always done about 5 heat cycles then a gentle ish ride before riding normal, never had any of my rebuilds seize or fail, obviously you don't wanna be holding it wide open for 2 or 3 rides but don't be afraid to accelerate, with a good forged piston and a few heat cycles you won't cause any harm.

Used 10w40 gear oil in mine with no issues, did replace clutch in 89 and suspect original plates contaminated as very "sticky" when I got them out

Took it into my college to ask my tutor what he thinks. (he builds race bikes) he said it looks fine and I could file it down very lightly. he also said the scratches on the outside were fine.

:grinning_face: :smiling_face_with_open_mouth: :smiling_face_with_open_mouth_smiling_eyes: :grinning_face_with_smiling_eyes: :smiling_face_with_open_mouth_closed_eyes: :face_with_tears_of_joy: 🤣 🤣

the proper cotton braided fuel purpose hoses last a lifetime

using clear ones for fuel is asking for trouble, they go brittle, crack, split, leak and are toss!

you dont need clear ones, there is 2 filters in the petcock and theres a filter in the carb fuel inlet barb too

thanks @Calum

Use a copper washer bud.

A general rule of thumb, the higher the compression the greater the power. On a two stroke, a great deal of power is made in the head.

But it's not a case of skimming the head, you need to modify skishband.

Read Graham Bells Two Stroke Performance Tuning for infinitely more detail.

@irongamer727 thanks lads

Very doubtful, check the part numbers from Yamaha, but I suspect they will be totally different as it's a totally different engine.

@dtr-nsr That's really odd.

As said then, I guess it is just reversible.

@irongamer727 And as I said, if it lines up with the port then happy days.

When I had the oil pump rebuilt part of the service was to adjust the oil delivery if required , never bothered as bike standard albeit with a forged piston.

Chains doesnt stretch, they wear. I have 28.000km on a 520 Did vx2 chain on my xt600... Imagine the reliability on a Dt 🙂

@calum okidoki

@declan Cheers man!

Top up the coolant and let the bike idle with cap off. Be patient, after a couple of minutes it will start to bubble. Then, a couple of minutes later, rev it slightly and watch more bubbles escape. I did this for a good 20 minutes. Note that there will be bubbles left, but once you get most out there should be no cooling problem.

@declan looks like I'll be doing a top end rebuild at some point After Christmas

@sgt-robuck-5 you don’t see too many of that era of dt I don’t know if there rare I’m just speaking from experience in looking to buy although you will find them usually it’s an older
Model that you will come across

Sounds like you've covered the fueling system, which means it's going to be an electrical component.

You will want to buy a new spark plug, HT Lead and iginition coil to rule out those items.

Next will be the pickup, if that starts to deteriorate then it will start to missfire.

Then unfortunately the CDI. But CDI's rarely fail, but I guess it is 30 years old.