250 The 1999 YZ250

PALMER84ONE

PALMER84ONE

Yes #29 is the oil seal and the tube is the PV breather tube. That is oil mix unburnt drizzling out of it.

If you have already done an order, let me know, I have extras. and they will mail for 47Cent
 
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Trfsrfr

Trfsrfr

PALMER84ONE:
If you have already done an order, let me know
Click to expand...
Yep, already ordered. I'm waiting for all the parts to arrive before I rip into it, so I haven't determined if it's leaking or not, but I would assume it is.
Plus I just broke the hauler so now I have a new project :thumbsdown:
 
Trfsrfr

Trfsrfr

Update after 5 weeks of not riding it:
So after waiting 2 weeks longer than was expected for my eBay purchase of Boyesen reeds to show up, they finally arrived yesterday and I removed the old ones and installed them tonight.
As I was expecting/hoping to find, the reeds that were in it were damaged as seen in the photo below.

Also since the instructions from Boyesen says that their reeds make the bike run richer, and since the afore shown pics of the latest plug chop test showed that it was starting to get closer to the mocha brown color, I removed the 170 MJ I put in it, and installed a 168.

And after installing the reed cage I did another compression test and I got 211psi!
Not sure if was because of the reed change or maybe I just didn't do it right the first time, but I am happy with the result.

I fired her up just to make sure she would run, but learned my lesson from my last crash on my buddies CR480 last Saturday, and decided to wait to get her into the dirt to do any tuning.Original Reeds.JPG
 
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Mihylo33

Mihylo33

Trfsrfr:
Update after 5 weeks of not riding it:
So after waiting 2 weeks longer than was expected for my eBay purchase of Boyesen reeds to show up, they finally arrived yesterday and I removed the old ones and installed them tonight.
As I was expecting/hoping to find, the reeds that were in it were damaged as seen in the photo below.

Also since the instructions from Boyesen says that their reeds make the bike run richer, and since the afore shown pics of the latest plug chop test showed that it was starting to get closer to the mocha brown color, I removed the 170 MJ I put in it, and installed a 168.

And after installing the reed cage I did another compression test and I got 211psi!
Not sure if was because of the reed change or maybe I just didn't do it right the first time, but I am happy with the result.

I fired her up just to make sure she would run, but learned my lesson from my last crash on my buddies CR480 last Saturday, and decided to wait to get her into the dirt to do any tuning.View attachment 30292
Click to expand...


Here is where the rookies go wrong. Did you use blue loctight on the Reed stop screws?
 
Trfsrfr

Trfsrfr

Mihylo33:
Here is where the rookies go wrong. Did you use blue loctight on the Reed stop screws?
Click to expand...
Yes, I did, and thank you for asking/pointing that out.
I ran it for maybe 10 minutes after install.
It had a funny smell again, my kid was covering his nose...
 
Mihylo33

Mihylo33

Trfsrfr:
Yes, I did, and thank you for asking/pointing that out.
I ran it for maybe 10 minutes after install.
It had a funny smell again, my kid was covering his nose...
Click to expand...


That's called premix. It makes men.

Not using loctite on those screws and not letting it sit is expensive.
 
Trfsrfr

Trfsrfr

But I did use blue loc-tite, and it's sitting right now (after 8-10 minutes run time), and will be for the next 2 days at least...
I am quite confident that those 4 machine screws will remain in place.
 
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Trfsrfr

Trfsrfr

Took the YZ out on the trail today for it's first real ride since I installed the new reeds, and put about 4 hours on it.
It didn't feel much different than before. Still kinda stumbles and misses a bit.
Since we had some issues on the trail I ended up towing 2 other bikes back to the staging area, and I did not get a chance to do a plug chop run.
After supercross tonight I yanked the plug cuz I was curious, and it was no longer the mocha tan color I saw last time, and was headed back to the dark/black, maybe even sooty look.
However, when I shut it down though, I was near idling with a bike in tow...

@M33, I got your reply in my CR80 thread.
 
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Trfsrfr

Trfsrfr

According to Boyesen installation instructions;
"Boyesen reeds tend to make engines run slightly rich on the main jet, and slightly lean on the pilot jet" and "If your carburetor has the stock main jet, it may be necessary to go down 1-3 sizes."
Stock is 172.
Because of what is above I decided to drop one size on the MJ and put in a 168.

Below is a pic of the plug after pulling into the staging area yesterday with the new reeds, and a CR480 in tow, slightly above idle, no plug chop, 168 MJ, above 1100 ft MSL;
Jan 29, 2017.JPG

Below is a photo of the plug from a month ago before the new reed install, with a 170 MJ, and a plug chop; 170 main jet.JPG

@M33 - my gut is telling me to lean it further...
All thoughts welcome...
 
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Mihylo33

Mihylo33

Trfsrfr:
According to Boyesen installation instructions;
"Boyesen reeds tend to make engines run slightly rich on the main jet, and slightly lean on the pilot jet" and "If your carburetor has the stock main jet, it may be necessary to go down 1-3 sizes."
Stock is 172.
Because of what is above I decided to drop one size on the MJ and put in a 168.

Below is a pic of the plug after pulling into the staging area yesterday with the new reeds, and a CR480 in tow, slightly above idle, no plug chop, 168 MJ, above 1100 ft MSL;
View attachment 30500

Below is a photo of the plug from a month ago before the new reed install, with a 170 MJ, and a plug chop; View attachment 30501

@M33 - my gut is telling me to lean it further...
All thoughts welcome...
Click to expand...

My instinct is telling me the bottom plug is too lean and the upper one is correct.
Yes it has some gunk on it but Yamalube is one of those sooty oils imo. The bottom plug has the carbon chipping off which leads me to believe lean knock.

Chances are that you might be lugging the bike in fear of a massive power hit. Just speculation on my behalf. The working power range in that bike is about 7-10,000 rpm I believe.
 
Trfsrfr

Trfsrfr

Mihylo33:
Chances are that you might be lugging the bike in fear of a massive power hit.
Click to expand...
Are you speculating that I am not getting on the pipe? If so, that is not the case.
We were out in the desert when we rode on Saturday and I let that thing rip whenever I had the chance.
It gets up and goes, but it doesn't feel clean, and feels like it could go some more.
It sputters a bit from about 1/4 throttle thru about 3/4 throttle. Kinda like it did before.
I'm not opposed to fatten up the mix as you suggest, just that I was working in the one direction and I felt it was getting there, judging by the plug.
 
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