YZ cylinder problems and sleeving

[yz125rider21]

Ok I am new to this been looking forever for a good forum to sign up to and I found this. I have a 2001 Y125 use to belong to a local pro race name Ryan Morris..I just blew up my top end on my bike and it is all ported and polished. I was wondering if I might be able to get it resleeved and my case it set up to except a 56mm piston and how could I determine of i could go to a 58mm from looking at case, cause i figure i gonna rebuild it mine as well go 144 with it, also would I have to run 100oct with the 144 cause really want to stay around 91oct...any suggestions???also what cylinders are interchangeable with this bike year just incase i cant find an 01 cylinder...pics be up in less than 15 minutes

 

[yz125rider21]

tried to post pics but says spamkiller????? :blah:

 

[yz125rider21]

marked the area where it is messed up sorry for the the ugly pictures lighting is bad right now...

 

[robwbright]

Send it to Eric Gorr for a 144. You can specify the type of powerband you want, as well as the amount of compression.

Lower compression = pump gas

Higher compression = race gas.

I think he's taking orders until April 28, then he's shutting down operations until fall.

http://www.ericgorr.com

He's advertising $475.00 for the complete kit including boring, plating, head mods, porting, polishing, case mods (if necessary), piston, ring, reassembly. He'll even pay shipping back to you if you prepay.

Here's my first ride report:

http://www.dirtrider.net/forums3/showthread.php?t=126800

Another post about 144's:

http://www.dirtrider.net/forums3/showthread.php?t=124121

 

[yz125rider21]

hey thanks for the help also do i send my whole motor assembled to him?...pretty new to this dirtbike forums cause i am go mechanic for car shop and usually know what I am doing, but now i dont and came to forums for help and so far so good...

 

[robwbright]

Call him and ask. Some bikes need case mods and some don't. I think the YZ does, but Eric will tell you for certain. I had to send my complete motor.

Eric's Number:

1-630-289-5645

It's usually best to call him first thing in the morning - 8:00 or something. It can be easier to get him on Saturdays as well. . .

BTW, I posted again in the 144 vs. 250f thread . . .

From this page:

http://www.eric-gorr.com/services/cylrebuild.html

"YAMAHA

1993-2005 YZ80/100 (92-105cc) $400
1990-2005 YZ125/150 (133,139,144cc) $475
1990-2005 YZ/WR (265cc) $500
(Minor crankcase mods required for piston clearance on big bores for YZ105 and YZ150, send the whole engine and the mods are included in the prices listed above)

WHAT’S INCLUDED WITH CYLINDER REPLATING KITS

1)Your top end parts are carefully inspected to trace the cause of mechanical problems to save you money and recommend mechanical solutions.

2)The top end is disassembled and cleaned. A detailed work order is prepared noting mods needed to repair things like water leaks, faulty exhaust valves, broken bolts, casting flaws and cracks. Steel and aluminum parts are cleaned with different chemicals to prevent corrosion. Max Power charges you extra for each of these services and then hammers you with a hazardous waste charge of $15 and $25 for cleaning. I don’t charge extra and this work in included in the price of the package.

3)Next the metal machining process begins, including cylinder boring, porting, polishing, resurfacing of the top and bottom of the cylinder, cylinder head machining, and exhaust valve mods for the larger bore. You get to choose the powerband and type of fuel. This enables me to design the cylinder porting changes and head mods based on the fuel and if the bike is ridden at high altitude. RPM charges upwards of $300 and you don’t get a choice of powerbands. I only charge a maximum of $85 for more complete work. My specs are designed using recognized standards set by the Society of Automotive Engineers. I use TSR and Dynomation software to accomplish these design changes. For more information check out my Two-Stroke Technology page.

4)US Chrome handles all of my nickle-composite plating (NICOM) and diamond honing. USC has the best honing tooling in the business and an experienced German honing engineer that provides the roundest straightest cylinder bores for the best performance.

5)After the plating and honing is completed I chamfer all the ports and relieve the exhaust bridge using right angle porting tools and three grades of polishing media. Most of the competition relegates these tasks to the lowest paid laborers in their shops, yet it is one of the most important tasks because if its not done correctly it can lead to premature piston and ring wear.

6)The top surface of the cylinder is critical to head sealing. I machine an anti-detonation ring on the top of the cylinder, none of my competition does that! I also hand-lapp the top surface on a granite surface plate with polycrystalline media paper. Most of my competitors use things like sandpaper and glass, a hideous concept that is bone-chilling to real engineers and machinists!

7)Finally the top end is assembled with all the studs and exhaust valves and checked for proper operation. New COMETIC gaskets are included and the WISECO Pro-Lite piston kit is checked for fit and the ring gap is set.

8)Your top end is lubricated and sealed in a plastic bag ready for shipment.

9)Return shipping, I charge $10-20 for return shipping and when necessary I upgrade your package to UPS AIR to get it to you by Friday for no extra charge. My competitors use return shipping as a way to gouge you for things like insurance, packaging materials, and upgrades for air. Sometimes these additional “hidden” charges can total $75-$100 more that their advertised prices! "

 

[yz125rider21]

so this is not a sleeve job at all its just a replating? I called the number and kept ringing cause you can see in my pic the top of the head is messed up on the ring closest to the cylinder and i dont know if it is repairable...also i saw a thing these top end pistons only last 10 hours? or was i seeing things

 

[yz125rider21]

bump

 

[yz125rider21]

It is freaking hard to get ahold of Eric Gore...I even emailed him so he could see a pic of my cylinder before i waste my time shipping it....

 

[robwbright]

He doesn't check his email real often - and he gets TONS of email. He is normally somewhat difficult to get in contact with, but probably more so since he's changing shop locations.

Call early in the morning or on Saturday. You could also post in the Forward Motion forum here:

http://dirtrider.net/forums3/forumdisplay.php?f=109

He or Rich will usually respond to any questions within a day or two.

Sleeve not necessary - bore and plate.

Here are some quotes from my research on the reliability of 144s:

My question from the following post:

http://www.dirtrider.net/forums3/sh...ad.php?t=123653

START QUOTE
"bclapham:

In a post before you mentioned that you had a 2002 RM 144. Could you please give me a bit more inf?.

1: Type of porting you had?

2: Maintenance compared to a normal 125?

Thanks

Rob"

bclapham's answer:

"1. mo better. low to mid is pointless on a 125 based bike (just IMO)- its supposed to be a high reving motor, so rev it. But mid to top is asking a lot from a novice rider like me, LOL.

2. dont know, i bought the bike as a basket case.

However, i will say i changed the ring every 5 race meetings, and the piston every 10 meetings. If that sounds excessive, the pistons from Eric are cheap and the gaskets can be had really cheap from www.peakmoto.com and bear in mind that each race meeting consisted of the bike carring a 230lbs Vet that should know better up and down the massive hills at Glen Helens back REM saturday races.

Man, was that bike fun."
END QUOTE


Here's Eric's take on 144 longevity:
START QUOTE
"Regarding piston life, thats a tough one. On my site I recommend ring changes every 5 hrs for experts and 10 for intermediates with piston changes double the time of the rings. But I have customers who have gone 2 seasons on a piston. Rich and I logged 100 hours on the same set of piston and rings on a 1992 RM144 that we rode at the OT National track. Rich called it the "Survivor Bike". We used good oil (MX2T) and changed the filter when it got dirty. However I know expert riders who can grenade a 144 is under an hour because they constantly rev past the power peak. Some cylinders like the YZ125 have such a wide exhaust with a narrow bridge and are made of an inferior casting alloy that they require frequent changes.

An important design change was incorporated in the piston by my buddies at Wiseco. My 58mm piston has a dedicated forge tooling that differs from Max Power, RPM, and Millenium. There are no milling reliefs on the outside of the piston so it has maximum surface area, its also longer so it rocks less in the bore. 50 percent of the mass is concentrated in the shallow conical dome where it belongs. The pin bore, ring land, and crown are hard anodized to resist wear. And now for 2006 Wiseco is coming out with a line of 58mm pistons to match each model whereas my piston is a universal that fits all 8 brands of 125s with modifications to the head and cylinder. The Wiseco products will match the same length, port, releifs, and crown configuration of the OEM pistons. That makes it easier for tuners to reconfigure and engine for a bigger bore. The new Wiseco line will probably feature special coatings too. I chose to keep my design for 2006 and the price down. Right now the other companies sell their 58mm pistons for between $125-$200."
END QUOTE.

On my stocker, I was planning on 1 piston/ring change in winter and a ring change in mid-summer - given the amount I get to ride. After talking with Eric and having the 144 done, I'm planning on ring piston ring over the spring/summer/fall and a piston and ring over the winter - and that's just to be safe.

BTW, I don't know what to make of the Yamaha info in Eric's post. You'll have to discuss with him.

 

[yz125rider21]

bought bike from pro so I dont know about port job...but it is a 2001 125 cylinder with a 56mm bore...and maitenance I just used 91 oct 32.1 ration and i think the jets are lean out one step down each over stock they where 2 down each but i was told to step them up so i dont lean it out sense i not a pro like he was.....but the piston is melted on the intake and exhaust side if that helps any

 

[yz125rider21]

I already tried posting in his forum area and it dont show it...can you please do it for me rob thanks...i want my bike back up asap....right now i stuck with a 2000 kx250

 

[robwbright]

I already tried posting in his forum area and it dont show it...can you please do it for me rob thanks...i want my bike back up asap....right now i stuck with a 2000 kx250

The moderator has to approve your post in that forum - it will show up when a mod reads it and approves - usually within 12 hours.

Saturday is only 2 days away . . . LOL

 

[Pete Payne]

Try Eric early in the mornings. You could go to a 144 but the front of the cases have to be opened up . The top of th cylinder shows erosion from detonation . It will need to be welded up , and remachined to repair it if an overbore does not take it out (clean it up )

 

[yz125rider21]

thing is i want him to look at it I dont want to send it in and land up paying way more money than i have to cause thats the case i find a stock cylinder and stay with it...I though when you do a 144 kit it pretty much wipes out the whole area where I was detonated at and starts fresh i will take a better pic in a few sense its finalllly sunny out

 

[yz125rider21]

Try Eric early in the mornings. You could go to a 144 but the front of the cases have to be opened up . The top of th cylinder shows erosion from detonation . It will need to be welded up , and remachined to repair it if an overbore does not take it out (clean it up )

haha I sent like 3 messages wondering why they werent showing, sure a moderator gonna like me now :bang:

 

[NacNac250F]

If your at a 56mm bore your already passed the stock bore and at something like a 132. It definetly needs a replate. I can see in the picture where you have a big score mark up and down the exhaust bridge. If you got your bike from a pro, then make sure its not ported. If it is then you will need to get it changed or a stock cylinder because a pro will have a much different porting configuration than a novice or even and intermediate. If you can't get a hold of Eric then there are a lot of other places you can send your cylinder to be replated.

 

[robwbright]

If you can't get a hold of Eric then there are a lot of other places you can send your cylinder to be replated.

Very true - but unfortunately, most of them are significantly more expensive - and the evidence I've read is that many of them can't/don't match his work.

 

[yz125rider21]

i am sticking to EG work no matter what but i took more pics i post them soon rob so stay tuned...

 

[robwbright]

If you read in Eric's forum, you may have to go elsewhere - it appears he closed up shop today until fall - serious sickness in family.

He made some recommendations as to other builders. . . One of those was Boyesen. Given how my father-in-law's Boyesen 125 Kart ran last year, I can see why Eric would recommend him.

 

[yz125rider21]

i will suffer until fall then this hella sucks

 

[yz125rider21]

do you know if a 02 cylinder and head fit a 01 yz125 with no modifications

 

[robwbright]

My guess is that all cylinders from that generation will work with little or no modification (for example, the current RM generation is from 2001-2006) - but that's a total guess. I'm sure someone who knows for certain will respond to your other post.

At the page below, Eric lists several 2001 YZ 144 cylinders ported and ready to go - you could probably do the case mods yourself, so then all you would need is some head work and the piston kit. . . I'm assuming he'd still sell you one of those if you can get him on the phone.

http://www.ericgorr.com/services/garage_sale.html

 

[yz125rider21]

ya but thats paying way more than his deal he gives us so I dont know unless he will give me the piston and stuff for a good deal...also i cant find his forum anymore on here

 

[RM_guy]

Get in touch with US Chrome. They can do major repair and replate it for a reasonable cost.