1999 YZ250: The Resurrection

VoodooHusky
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Roseville, CA US
3/25/2019 4:29pm Edited Date/Time 4/11/2020 2:11pm
I just purchased a 1999 YZ250 from a friend and it hasn't been started in 12 years! My friend was the second owner and only rode the bike four times. The tank was drained but nothing else was prepped before it was stored. The bike is completely stock with the exception of a FMF silencer/SA. It even has the original tires on it! I'm going to go through the bike mechanically and keep it mostly stock and will use Jeremy McGrath graphics. I've got a bunch of questions as I've been out of dirt bikes for almost two decades and haven't totally kept on on the latest tech.

Initially I'm going to:
Rebuilt the carb
New plug
Change the motor oil
New air filter
Flush the tank
New fuel hose
New brake fluid

The bike ran fine when last run and I haven't even kicked the bike over. I'm going to put a few cc's of two stroke oil in the cylinder before I kick it over and kick it several times with the old plug installed. I'm open to any other suggestions that I should do before I fire it up.

Once running I'm going to take it out for a shakedown ride and then possible put a new ring in it and of course decarbon the PV and piston/head at the same time.

Plan is to have Race Tech upgrade the suspension and I'm open to suggestions here as well.

New tires, chain and sprockets are in the plan as well and I'll probably run a 51T on the rear.

1. First question: what 2T oil are you guys running and what ratio? The manual states 30:1 but that seems rich.

Here's a few pics of the bike in my driveway before I started cleaning it up. I don't think the left radiator was bent like that from the factory. LOL








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VoodooHusky
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3/27/2019 7:05am Edited Date/Time 3/27/2019 7:06am
Well I started tearing into the bike yesterday and found this. My friend said the bike always ran fine but felt the bike didn't have the power he thought it should. Now we know why. I'll do a little cleaning and then pull the head later today and see how the top end looks.

Anyone want to share what ratio premix you're running on their 99+ YZ250?



soggy
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3783rd
3/27/2019 7:37am
good lord, what a bummer for a bike that was only ridden a few times. i ride an 03 kx250 and mix at 36:1 usually. Pick a ratio anywhere in the 32:1 - 50:1 area, jet for that and stick to it. don't need to overthink it too much.
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VoodooHusky
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3/27/2019 7:42am
Thanks.

My friend only rode it 4 times but the original owner took it to Sand Mountain and had a paddle tire mounted on it at one point. I never like riding bikes in sand.
3/27/2019 8:13am
Thanks. My friend only rode it 4 times but the original owner took it to Sand Mountain and had a paddle tire mounted on it at...
Thanks.

My friend only rode it 4 times but the original owner took it to Sand Mountain and had a paddle tire mounted on it at one point. I never like riding bikes in sand.
VoodooHusky,

Great find!
It does look as though you will need to go OVER the whole Engine with a fine tooth comb, you have a great Platform to build off of with a minimum expense. Make sure you don't have ANY AIR LEAKS, this will cause all kinds of problems.
I would run Maxima K2 Oil, 40 to 1 Ratio, with a 45 Pilot, to minimize Spooge from 0 to 25% Throttle opening. IF, IF you REV the HELL out of it, only then will 32 to 1 WORK. Remember it is a Race Bike meant to REV the Hell out of.


If you have to consider a NEW PISTON, GASKETS AND RINGS, you might consider a Big Bore Cylinder Kit. A $170 outlay might get a new Yamaha 250 cc Piston, Gaskets and Rings, but a $550 to $700 additional would get you a YZ ESR 325 Big Bore, with only a change to smaller Jets.

https://www.eddie-sanders-racing.com/category-s/126.htm


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The Shop

VoodooHusky
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Roseville, CA US
3/27/2019 8:27am
LOL I was looking at that website last night. If the cylinder is trashed I might go that way.

I'm leaning towards 40:1. I'm a 60 year old intermediate and not holding the throttle wide open nearly enough. I'll ride MX with it along with trail riding and desert. I'm also trying to find a ratio that will work with my 1983 Husky 250CR so i have just one gas can. But I don't really want to compromise and cause issues.
VoodooHusky
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3/27/2019 2:47pm Edited Date/Time 6/1/2019 8:11pm
Close, that's an 1984. 1983 was the last year of the aluminum tanks, twin shocks and first year of water cooling. Here's mine. Long story cut short: I'm the original owner and sold it to my friend 30 years ago so his dad could ride it. Two boys later that rode it and it's still all original the way I set it up including the numbers! Basically a stock bike with a PC exhaust and Fox Forx that are both pretty rare in the vintage MX world. I was visiting him this past summer in Ohio (I'm now in NorCal but we both grew up in SoCal) and noticed that it needed a little TLC. I just retired so offered to buy it back. He will ship it to me any day now. Plan is to go through it mechanically and clean it up. We're going to race it in the Husky World Championships next spring in SoCal. He's faster than me so I'll race the 60+ class and he'll race the Evo 250 class. My friend was a Husky support rider in 1984 for D37 races.








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VoodooHusky
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3/27/2019 2:55pm Edited Date/Time 3/27/2019 2:57pm
It's raining here today so I worked on it a bit and got the head off. I'm happy to report that it doesn't look nearly as bad as I was expecting. There are a few marks but frankly nothing far outside of normal. I'm not as familiar with the chromed liners and how they're supposed to look so feel free to expand the photos and let me know what you think. My thought was if the cylinder was trashed I'd tear it down and go through the bottom end too. But now I don't think so. I'll get the cylinder off tonight or tomorrow. I guess I'll take it to a shop and have them check the tolerances. You don't hone these cylinders right?
mattyhamz2
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3/27/2019 4:18pm
Yamalube 2R 40:1 with C12. She'll run like a bat outta hell!
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3/28/2019 1:59pm Edited Date/Time 3/28/2019 2:01pm
Your Husky 250 CR looks cool, cleaning it up should be fun. Any chance of getting the original Side Plates?

fun.
VoodooHusky
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Roseville, CA US
3/28/2019 3:21pm Edited Date/Time 3/28/2019 3:35pm
Your bike looks fantastic. I like the idea of adding a lot of white to the bike.

I have the original side covers and rear fender along with the pipe for the Husky. I'm probably going to leave it the way it is as that's the PC look back from the early days of Pro Circuit. Their race bikes in 81 and 82 used custom side covers along with the rear fender/number plate combo. Although Andy Jefferson's 1983 250CR used the stock side covers. My friend made those side covers and I helped him. He sold them through Cycle News but only sold maybe 20-30 sets. The stock side covers make the bike very wide.

Here's some photos of the top end completely off. Stock porting and possibly the stock piston. I did not see any witness marks from the top end ever being off. The barrel was a challenge to take off with the corrosion on the studs. Note the two divots on the intake side of the piston to the left of the intake hole. There are some scratches on the barrel but nothing you can feel with your finger nail and nothing that looks alarming. I also cannot detect a lip at the top of the barrel. Note the photo of the crank and the stops on it from what appears to be moisture. There is also a lot of oil on the crank halves which can't be good. I'm taking the top end to my local Yamaha dealer tomorrow to have them inspect and measure it. Hopefully I can just put another piston in it and go.












sandman768
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Saratoga Springs, NY US
3/28/2019 3:34pm
99 was my first new YZ250 after riding Honda’s for 8 years, great bikes. 32-40:1 with splash of race gas will run good, get the latest yz250 carb needle, it’s slightly richer & will help with detonation. Got lucky with the way that carb looks, I would replace main bearings & seals just due to sitting so long...
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VoodooHusky
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3/30/2019 2:02pm
I took the cylinder to my local Yamaha dealer and they checked it and said it's in spec and looks good. l ordered a new piston, rings and everything else needed and might have it back together next weekend. I've got a lot of cleaning to do between now and then and some painting as well. I'll get new chain and sprockets ordered on Monday.

I need new tires. Here in NorCal we have mostly hard pack and I'll be riding MX and do some trail riding. I'm looking at the Bridgestone X30 tires F & R or maybe the X40 for the rear. I'm open to suggestions so it you have any throw them my way.
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hubbardmx50
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Rancho Cucamonga, CA US
4/5/2019 6:31pm
How much was the graphics kit and where did you buy it from? Looks really nice. I might be picking up an 01 as a little project tomorrow. Nice build, Motocross Action usually has all the carb specs on what needles, jets and clip position they ran on these bikes on their website. They seem to be a fan of the KYB forks from this generation. Yamahas always have the best suspension.
VoodooHusky
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Roseville, CA US
4/5/2019 9:16pm Edited Date/Time 4/5/2019 9:18pm
Thanks. I didn't buy that graphics kit but here's the link.

https://www.ebay.com/itm/YAMAHA-YZ125-YZ250-1996-2001-USA-Factory-team-…

I did custom order the 1999 McGrath kit. EVOMX didn't show the tank and rad graphics so I contacted them and they are making them for me. I wanted the same graphics McGrath used in 1999 but it cost me. I should have them in a couple of weeks. I ordered number plates as well but I'm too slow for #1 so I went with #11.

https://www.evo-mx.com/shop/yamaha/mcyz32/

Update:

The Wiseco piston kit arrived today but it won't be going on anytime soon. I've determined the wet crank seal is leaking so I'm going to replace the wet and dry crank seals but not split the cases. Since the bike is 20 years old and original I'll replace the water pump seals and bearing while I have the side case off. I'm looking for someone locally to do the work but I think I'll end up doing it myself. It's been a while since I've torn into a two stroke but I'm sure I can handle it. I'm working on a parts list before I tear into it. I'd like to have all of the parts so when I do take it apart and I put it back together immediately. Wish me luck!

Any recommendations on the tires? Bridgestone Battlecross, Dunlop Geomax and Michelin Starcross all look to be good options.

Part of what I ordered and what it should look like:






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VoodooHusky
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4/9/2019 9:16am
I made more progress on the bike over the weekend. Mainly cleaning it and preparing parts to be reinstalled. I took apart the airbox/carb boot as it was so dirty. I noticed what looked like grease used as a gasket. I hope that's what it was and I used Bel Ray Waterproof grease for reassembly.




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VoodooHusky
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4/18/2019 1:49pm
I'm back from vacation and time to get this finished up. While I was away the graphics kit arrived. I've got a new plastic kit on the way so the install will have to wait. I have all the parts for the top end ready to go so I can put that back together. Then on to the carb rebuild.

I still need to buy new tires and I'm looking for suggestions.


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psg119
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Menifee, CA US
4/18/2019 3:07pm
I'm back from vacation and time to get this finished up. While I was away the graphics kit arrived. I've got a new plastic kit on...
I'm back from vacation and time to get this finished up. While I was away the graphics kit arrived. I've got a new plastic kit on the way so the install will have to wait. I have all the parts for the top end ready to go so I can put that back together. Then on to the carb rebuild.

I still need to buy new tires and I'm looking for suggestions.


Switching to the #11 now you got yourself a Jimmy Button replicaTongue He was pretty damn fast too! Haha!
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VoodooHusky
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Roseville, CA US
5/7/2019 7:49am
Getting closer to finishing this up. I have someone replacing the seals and if I have the bike back this week I should have it fired up this weekend. Then I need to get the new tires mounted and I'll be ready to get it dirty.




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RABnasty
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Temecula, CA US
5/7/2019 11:41am
Hell yeah im going for this same look on my 96 can’t wait to see how this turns out
VoodooHusky
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5/11/2019 8:10am Edited Date/Time 5/11/2019 8:11am
Gotta love new tires. Battlecross X30F and X40R. My 1999 YZ250 is ready to be put back together but I'm still cleaning it up. I've got all day to work on it so it might happen today.


VoodooHusky
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5/16/2019 11:16am
Got it back together but waiting on a part. Will fire it up tomorrow.



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RABnasty
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5/16/2019 10:58pm
Looks so good! Great job, seeing this makes me want to get mine done!
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VoodooHusky
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Roseville, CA US
5/18/2019 9:08am
Fired up the bike and it ran well and no leaks! I still need to check the suspension settings and set the sag. Then bleed the brakes and it's time to get it dirty. Next weekend is looking good.



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VoodooHusky
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5/30/2019 4:33pm Edited Date/Time 6/1/2019 8:37am
Quick update as I haven't taken the bike out yet but will tomorrow. I've been looking for some nice clutch and ignition covers to replace the stock ones and have been looking high and low. Nothing really looked that good to me other then the pricey billet covers from Pro Circuit and the others. I originally bought a Boyesen clutch cover and while looking for an ignition cover I came across Luxon MX in San Diego. I had never heard from them before so as I researched them I ran across several posts on Vital MX. Billy Wight the owner had some very good and detailed posts so all looked good.

I sent him an email regarding a fitment question I had and he was quick to respond and assured me their YZ250 covers would fit my 1999 and if not just return them with no questions asked. Luxon MX is a Vital MX vendor and he mentioned to me they have a forum discount. I purchased the covers online and I received an email shortly after that the covers were shipped and would be here within two days.

They arrived today packaged safely in some environmentally friendly packaging so I was off to my garage to install them. The quality of these covers are significantly better than the stock or Boyesen covers I have and look to be EXACT copies of the OEM pieces. From inspection they looked like they would fit with no issues and they did. I can't imagine any of the other known and expensive billet covers could be of better quality or fitment. They also offer clutch covers with some extra room for aftermarket clutches. Looking at their website they are making some very cool high quality pieces. You can check out their products here:

https://luxonmx.com/

And here are some photos before I get them dirty.

@luxon MX






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