1989 YZ250WR

[450exc115]

Dana as I think about it I bet Yamaha used the same spline for nearly all the YZ/IT stuff.. Probably what is specific is the steel actuator on the shifter drum side. You could buy a new shaft from a similar year and then have the shop weld on the old actuator... Just a thought.

[FATDADRACING]

450exc115 wrote:

Dana as I think about it I bet Yamaha used the same spline for nearly all the YZ/IT stuff.. Probably what is specific is the steel actuator on the shifter drum side. You could buy a new shaft from a similar year and then have the shop weld on the old actuator... Just a thought.

Exactly what we’re doing. He’s also going to turn a few extra shafts with some harder steel for future experiments.

[FATDADRACING]

My first attempt at restoring plastic went about as well as anything else I’ve done for the first time..they look worse than the ol yeller ones I’m sending back tmrw... ordered new aftermarket today. Pics don’t show the full suckness of either


Sent from my iPhone using Tapatalk

[FATDADRACING]

FATDADRACING wrote:

My first attempt at restoring plastic went about as well as anything else I’ve done for the first time..they look worse than the ol yeller ones I’m sending back tmrw... ordered new aftermarket today. Pics don’t show the full suckness of either


Sent from my iPhone using Tapatalk

Progress on re assembly is slow


Sent from my iPhone using Tapatalk

[dwarf66]

The old fenders look perfect. I wish mine looked like that. What did you do exactly. Hair product? Peroxide? What brand and how long. any sanding?

[FATDADRACING]

Marc, they really look bad up close...all I did was sand with 150,220,500,1000 grit sandpaper, lacquer thinner and some plasti coat clear gloss. A lot of work for the result I got. I’ve heard that buffing with automotive type compounds is the real deal, and 40% peroxide based cream hair lightener and a bag in the sun is the way to go...Ain’t nobody got time for dat! So I just got new so I can be pissed at myself some more when I wreck em.

[RM]

I get the concern for aesthetics but just grab another gear -it’s harder to see plastics in 3rd or 4th...

[MikeDi]

plastic resto was my favorate,, now i can't stand dealing with it.

[FATDADRACING]

Anyone have a set of or even pics of some radiator guards for this? I have an idea based on newer ones to fab a set, just looking for input , or a set to bolt on with some mods...

[FATDADRACING]

ECL wrote:

I believe any resto that starts with a powder coated frame should be called a BOAT. Anyone that has owned a boat knows that BOAT stands for break out another thousand. Ask MikeDi, he'll tell ya all about it.

So, I could have a lot of boats by now....I’m almost done buying, need to restrict my eBay viewing time..

[FATDADRACING]

FATDADRACING wrote:

ECL wrote:

I believe any resto that starts with a powder coated frame should be called a BOAT. Anyone that has owned a boat knows that BOAT stands for break out another thousand. Ask MikeDi, he'll tell ya all about it.

So, I could have a lot of boats by now....I’m almost done buying, need to restrict my eBay viewing time..

Well, it looks good, but it should run way better than it did for all the boats I put in it...any idea what needle came stock? I have two carbs and each is different jetted.


Sent from my iPad using Tapatalk

[ECL]

Jetting is voodoo science to me, but google 1989 wr250 stock jetting. The first result should be a thread from thumper talk discussing your bike. Lots of info there it seems.

[idiotboy]

part number says J8-6JD8-63 if that helps...

[FATDADRACING]

Yup, that’s the one in the old carb, new carb came with way shorter needle....thanks.
Next question, I installed a reed block spacer in hopes of gaining some low end...anyone use these and will it affect jetting?

[sjsst41]

Dana - that motor in stock form should have had a solid low to mid-range. Is that not the case?

[FATDADRACING]

sjsst41 wrote:

Dana - that motor in stock form should have had a solid low to mid-range. Is that not the case?

The only time it ran clean was WFO last week..I’ve since put the jetting back to stock, but get a big burble in the middle when shifting, and it takes a long time to idle down in neutral.
Stock: 60 pilot 340 main needle in 3rd position ( middle)
New carb: 45 pilot 370 main needle didn’t matter because it was almost 3mm shorter than stock.

[oldschool]

FATDADRACING wrote:

sjsst41 wrote:

Dana - that motor in stock form should have had a solid low to mid-range. Is that not the case?

The only time it ran clean was WFO last week..I’ve since put the jetting back to stock, but get a big burble in the middle when shifting, and it takes a long time to idle down in neutral.
Stock: 60 pilot 340 main needle in 3rd position ( middle)
New carb: 45 pilot 370 main needle didn’t matter because it was almost 3mm shorter than stock.

If a 2T won't idle down, that's a lean pilot...

And the burble in the middle is FAT (rich needle or it's clip setting)

[oldschool]

This is one of the better write ups out there on 2T carb jetting. It will help you get through the voodoo science

https://www.duncanracing.com/TechCenter ... etting.pdf

[sjsst41]

Dana - I see you referenced this FMF info for recommended settings.

http://www.fmfracing.com/Content/Instru ... 000346.pdf

What needle is in your bike now?

[FATDADRACING]

sjsst41 wrote:

Dana - I see you referenced this FMF info for recommended settings.

http://www.fmfracing.com/Content/Instru ... 000346.pdf

What needle is in your bike now?

Stock needle 6DJ8-63 middle position

[sjsst41]

Dana,

So what's in my 38mm TMX is 6EJ12-58

Seems to be working well, wanted to purchase the stock needle, but can't find stock anywhere.

On a side note - the pilot jet was 20 ! I ordered a 45 today.

FATDADRACING wrote:

sjsst41 wrote:

Dana - I see you referenced this FMF info for recommended settings.

http://www.fmfracing.com/Content/Instru ... 000346.pdf

What needle is in your bike now?

Stock needle 6DJ8-63 middle position

[FATDADRACING]

Carb issues, now overheating.. so I pulled the head today after checking the timing.. head gaskets looked good, however there’s way too much fuel going in. It looked like the power valve was hitting the piston, but it’s actually just floating around. The dowel pins are gone and the bolt threads that hold the two halves were stripped out. Only half the valve was ever working.. should have a lot to do with the jetting I think,lol. Back to the machinist.


Sent from my iPhone using Tapatalk

[JackPiner]

Is this for sale yet?

[FATDADRACING]

Not yet, I’m not done fixing it ....

[FATDADRACING]

Was hoping to try this little trick this weekend. I called Rich Daly at Dynoport Monday and it was here today!


Sent from my iPad using Tapatalk