I need some YZ125 conversion help

[QuadJunkies]

As alot of you already know, we are wanting to start a Blaster/YZ125 conversion next month and.....


I think this is going to be ALOT tougher than we 1st thought! lol

All the research on suspention and how to get the motor to fit, clearing the swingArm and.....What about the vibration??? I know she has a TON of it already in her mini she races now ,but Im guessing this wil be more
I have a couple ideas on suspention, but Im not really even sure where to start. lol

Anyone know of a good place to find some info on this conversion?? WE are going to need all the help we can get. Troys feeling overwhelmed right now on where to even start !!:scary: :p

Ive heard others mention people who have done this, but we have never seen one .

Im not sure what else would work well in the Blaster frame and still have alot of good power.

[Livin4Real]

A YZ125 is going to have insane power in that chassis. Most run a cr80 and when setup right they are wicked fast. I watched D.J. Spurling clear the 100ft. tabletop at Wildcat a couple weeks ago every lap on his 90 mod. Every time he got close to the tabletop, the announcers would say "stop what your doin' folks and keep your eye on the tabletop" and sure enough next thing you saw was DJ flyin' over it like a pro, awesome :eek2: I think Brad Loomis has done the conversion, check with him or if you can hunt down Spurling, surely someone on here can get in touch with them.

[LT80]

I'm with livin, all are 80cc's that I've ever seen.
I did the CR80 blaster thing myself. We had it in, in a few hours.

Look for a guy in other forums called ZORG. He did it also and had good ideas.

My 2nd thought would be: where are you going to race it?/ What class? No class for it that I know of.

DJ is fast!!! Course it's from years of hanging on to a Moore motor. :D:D

[markvette]

its gonna shake every bolt and nut loose on the quad.

Mark

[QuadJunkies]

Originally posted by LT80
I'm with livin, all are 80cc's that I've ever seen.
I did the CR80 blaster thing myself. We had it in, in a few hours.

Look for a guy in other forums called ZORG. He did it also and had good ideas.

My 2nd thought would be: where are you going to race it?/ What class? No class for it that I know of.

DJ is fast!!! Course it's from years of hanging on to a Moore motor. :D:D

I would think the weight of the Blaster wouldnt be as competitive with a 100 lbs rider :confused: but Im concerned about no Counter Bal.

There actually is a series she can run that set up with,but we may have to rethink the motor :(

Isnt it hard on a CR80 in that big of a Chassis and all the added weight?

Ive seen the CR motor,they are def fast but never seen one in a Blaster frame.


Im trying to keep her in a quad that will allow her to still run a clas with kids her own age.Im not ready to let her race with all the adults just yet at her size.
The reason for using the Blaster frame is it fits her so well and we already own it .
Shes ready for an upgrade in power.

[QuadJunkies]

Originally posted by markvette
its gonna shake every bolt and nut loose on the quad.

Mark

her mini already does that !:p LOL J/K

I dont know how the mini riders race with all the vibration

[joshridina400ex]

do a 250r chassis with a 250f motor. you can get chassis and motors really cheap on ebay. i might be able to get you a cheap 250r frame.

[QuadJunkies]

Originally posted by joshridina400ex
do a 250r chassis with a 250f motor. you can get chassis and motors really cheap on ebay. i might be able to get you a cheap 250r frame.

Thatsjust it... We already have a quad, its brand new and cant be buying another quad to build it up.
Josh, she's only 12 :p lol

When she gets ready to graduate out of the Conversion quad, she will go full sized after that

[QuadJunkies]

Brandons gonna be the lucky one cause hes going to have all these back up quads when his sister moves up! :p :blah:

[Pappy]

QJ, there is minimal weight difference between the blaster chassis and a jb 90 mod chassis.

The CR85 engines can be had all day long for less then $1500, and thats for a NEW engine. She would then be able to run in multiple classes as a good set up will be competitive in most classes.

[newnick]

Around here the 90mods run with the Blasters and 300ex's. There is two age groups. We're gonna just build a Blaster or pick another one up all ready setup and run it with the Blaster motor. I thought about the 90mod but I can't see why it would be worth the work or expense when the Blasters do just fine the way they are.

[QuadJunkies]

Originally posted by Pappy
QJ, there is minimal weight difference between the blaster chassis and a jb 90 mod chassis.

The CR85 engines can be had all day long for less then $1500, and thats for a NEW engine. She would then be able to run in multiple classes as a good set up will be competitive in most classes.

Thats what Troy and I was just talking about a few minutes ago with him . He thought it would be comparible weight, if not LESS..And ALOT less work and expense!

:p

As long as this build will be competitive, then this might be the way to go. She could run 3 classes with the Cr motor too.....

But I bet the power of the 125 would sure be sweet though :devil:

[Pappy]

Originally posted by newnick
Around here the 90mods run with the Blasters and 300ex's. There is two age groups. We're gonna just build a Blaster or pick another one up all ready setup and run it with the Blaster motor. I thought about the 90mod but I can't see why it would be worth the work or expense when the Blasters do just fine the way they are.

I agree, and if someone with the knowledge and where with all would build billet engine mounts and a pipe, this would eb the hot ticket for a TON of people.

[newnick]

If you could, expand on that Pappy. Sounds like theres something I need to be aware of before I jump into this next season.

[Pappy]

The biggest issue when doing a hybrid, is the exhaust. On a 4 stroke its not that bad really, and anyone with welding expierence can build a head pipe using the donor bikes pipe.

On a 2 stroke, the expansion champer is more then alot of folks can manage building themselves. I think LRD used to make a pipe for a few conversions, but I dont think they do any longer.

The blaster has been around forever, fits a majority of the younger sized riders, and I cant believe a company has not jumped on building the pieces needed to make a yz85 swap kit. If they would, it would sell faster then they could make them. I know I would have built Cody one of these if only someone would have a ready to go kit. I called a few of the well known builders and they said they would build it, but it would be very very expensive and would take alot of time for them to get around to. Thats not really what i wanted to hear:p

[Pappy]

Here is a shot of a 400ex with a blaster engine.

[Pappy]

It would be a great quad for a youth rider who is taller. like QJ's daughter

[Pappy]

My son loved it, but he is still to short to make it work. He would do far better on a blaster/YZ85 hybrid

[BradLoomis]

Tina,
The YZ125 in the Blaster frame is not what I would do. I am in the middle of quite a few different builds right now.

1. Honda stock 250R with CR85
2. + 7 single A-arms Predator 90
3. Graphite rear axle on Bud Fischer shifter 90
4. JP Racing 250R with CRF 250F
5. many, many more

I personally don't like the Blaster because of it's weird geometry. When you go to widen them the swing arm location makes it nearly impossible to lengthen it without the suspension getting way to twitchy. If you are going to do this, get a hold of Jim @ Diamond Racing (http://www.diamondracingatv.com/) he is the only one that I have ever seen that understands the geometry issue, and will help you through this, tell him I sent you. The 85cc motor is more than enough for the Blaster, my question is why you don't just let her race the Blaster with the 200cc motor it ? I know she is more than capable of handling it with the proper suspension under her!!!:D :D :D

[Pappy]

Brad, who is making the pipe for the 250R/85 hybrid?

[BradLoomis]

I am.

[Pappy]

Make sure you post a pic when its completed. id like to compare it with a few others i have seen.

[bear dad]

what are the classes you can race when you take a larger quad and put in a cr85 engine, and is there an age limet to this, the bigest thing is what determins the class, the engine or the quad size

[QuadJunkies]

Originally posted by BradLoomis
, my question is why you don't just let her race the Blaster with the 200cc motor it ? I know she is more than capable of handling it with the proper suspension under her!!!:D :D :D

So she can race 91-125cc 12-15 yr class with kids her own size/age group. She will move up for full size then.:) I am not ready to fully unleash her just yet lol

I appreciate all the help,now I sit an worry about a pipe :confused:

[Pappy]

I think for the most part it will depend on the local sanctioning body. We could run a 85cc, but it would be in the 90 mod class, or we could enter it in the blaster class 200-300cc locally.

In the nationals, 90 mod and maybe the 200cc-300cc classes but I havent looked at a GNC class listing. The GNCC series wouldnt even let one on the course:ermm:

[QuadJunkies]

Originally posted by bear dad -
what are the classes you can race when you take a larger quad and put in a cr85 engine, and is there an age limet to this, the bigest thing is what determins the class, the engine or the quad size I think that all depends on which series you run. In the WORCS, they had a mix of the faster minis and shifters, I suspect soon the shifters will be running there own class. Pappy, back East do they run sticktly shifters in one class ? I was thinking they did.

My Daughter was able to race a sport class as well and they shared gates with the Womens class this spring, that has since changed.

[QuadJunkies]

Originally posted by Pappy
I think for the most part it will depend on the local sanctioning body. We could run a 85cc, but it would be in the 90 mod class, or we could enter it in the blaster class 200-300cc locally.

In the nationals, 90 mod and maybe the 200cc-300cc classes but I havent looked at a GNC class listing. The GNCC series wouldnt even let one on the course:ermm: I posted a minute too late :p

[Pappy]

Yep, even Cody's 125cc 4 stroke hybrid had to run the 90 mod class. Actually they made up the class just so he could race...himself:ermm:


Cody won the shifter class against cr80 powered quads at a NQRA TT race a few years back on his TRX90:p He wanted me to build him one then but finding the pipe or having it built was and still is the draw back.

Rick Hetrick told me if I brought the engine and frame up he would build the pipe so I know I can have it done by someone fairly close to me. I have seen so many that were so poorly built that they just didn't make any power so its an area I would prefer to have someone I have confidence in building.

A lot of folks will say.."buy the cobra", but honestly I just don't feel like buying something that he will out grow or break to pieces. The 250r hybrids are looking very good now that Cody has done a little growing, but even on his 300ex he is still suffering from his lack of height:p The 250r would just compound the problem for now. Atleast with lil QJ you can concentrate on the power output...that girl has reach:D

[Pappy]

QJ...I remember that pic you posted awhile back showing how tall your rdaughter had gotton...


Here is cody a few weeks ago...standing next to the 400ex, his chin just clears the bars:p

[QuadJunkies]

Originally posted by Pappy
. Atleast with lil QJ you can concentrate on the power output...that girl has reach:D

LOL. Boys are just Late Bloomers, he will get his hieght soon!:D

I just want soooo badly to do this right and make this a competitive quad for her,she deserves a good handling quad but I cant break the bank doing it.She is REALLY excited to do this, yet kinda nervous leaving her mini but she knows shes just getting too tall for it. :( She can still ride is very well and wil Cont. to until this one is done I just dont want a conversion nightmare on our hands. You deal with enough of that daily just buying ready made parts :ermm: Were also not happy with whats out n the market for the i"in between" kids for quads who want to race. This just seemed liked a good solution.

[Pappy]

But he rides like he is 10 feet tall:D

Your in the same boat as we are. Tired of spending money on short term parts.

[LT80]

I've seen a few 250R/80's. Downright shame the parents put the time into it just to be blown away.
Way too heavy. :(

FYI: when I did the conversion, I ground the bottom mount of the 80 motor enough that the sprockets lighned up. Welded 2 pieces on to make the front mounts. Another 2 pieces to mount the radiator. The stock CR80 pipe fit with very lil bending.
This was a surprisingly easy and fast switch.

[Pappy]

LT80, do you know off hand how much your hybrid weighed in at? I am actually surprised to find how close alot of the chassis are when they are bare, and I have had concerns about overall weight in the past buy never took the time to compare a few set ups while we had the engines out of them.


I have more of a concern with how well a smaller rider can "work" the larger chassis. I have cringed at more then one national watching the 90 mod riders "hang on".

Interesting about the stock pipe...I will admit I never evn considered it being I have been told that a custom pipe was needed. I broke my own rule...KISS:p

[QuadJunkies]

Originally posted by Pappy
LT80, do you know off hand how much your hybrid weighed in at? I am actually surprised to find how close alot of the chassis are when they are bare, and I have had concerns about overall weight in the past buy never took the time to compare a few set ups while we had the engines out of them.


I have more of a concern with how well a smaller rider can "work" the larger chassis. I have cringed at more then one national watching the 90 mod riders "hang on".



We have been curious as well about weight and I cant agree more on these kids working the larger Chassis. Im also concerned about traction and suspention being CORRECTLY set up for the kid between there lighter body on a full sized chassis.

[QuadJunkies]

Originally posted by Pappy
QJ...I remember that pic you posted awhile back showing how tall your rdaughter had gotton...


Here is cody a few weeks ago...standing next to the 400ex, his chin just clears the bars:p
Kelsey said she wanted to show ya some pics of her riding my quad today..She grew even MORE since shes had been on it :(
http://i.pbase.com/g4/26/660826/2/64674963.VYlyRC1d.jpg

http://i.pbase.com/g4/26/660826/2/64674960.u8bDmT0V.jpg

http://i.pbase.com/g4/26/660826/2/64674962.pivSggxc.jpg

I didint get the best pics today,just some quick shotscause it was WAY too hot to really be riding long today.
http://i.pbase.com/g4/26/660826/2/64674955.4Og49FgA.jpg

http://i.pbase.com/g4/26/660826/2/64674954.GQDUgmrY.jpg





she does well on it ...For herSize.. But I got to see 1st hand that she doenst have the muscle to manvuer as well as her other two quads ,mine is also so stinkin wide that on the trails shegot hung up easier .. :p
http://i.pbase.com/g4/26/660826/2/64674953.kHOpF4wR.jpg

[QuadJunkies]

She makes it look like a Cobra! :p lol

http://i.pbase.com/g4/26/660826/2/64674958.0sptjn9Q.jpg

[QuadJunkies]

Now Brandon is MORE than ready to step in a take over her motor in his . He wants her OFF the mini and to hurry up about it ..:p :macho
http://i.pbase.com/g4/26/660826/2/64674900.feUcGkVT.jpg
http://i.pbase.com/g4/26/660826/2/64674899.hZgkirEo.jpg

Her Blaster motor had some motor issue today,so she shared mine .. Glad its still under the 6 month warrenty as we think there is some top end issues going on,she had no spark today:ermm:
I thought Blaster ran forever?Heck...Its still stock!:confused: Maybe good were looking for a new motor to take its place afterall.

[camsdad]

fyi.....i just weighed a blaster/cr80 quad,304pounds...thats with a plus2 swinger,and beadlocks....cam's 70 mod weighs 274 with a ti-axle setup and it a dc motorsports chassis.the cr80 power blaster will pull me around just fine at 190 pounds..cam weighs 93# and can beat 115cc stroker mini's with good riders every time.

[QuadJunkies]

Thanks for the info on the weigh in! :cool:

[newnick]

QJ, it looks like your daughter is big enough to just move up to a Blaster or 300ex. She has the experience from the mini and it wouldn't take much seat time for her to adjust to the bigger quad.
Theres a boy racing with my son in the supermini class thats 9yrs. old he also races in the youth class on a 300ex and does good in that class. He also looks about a foot shorter than your girl.
That would save you alot of the headaches of building a mod bike.

[Livin4Real]

The heck with quads, give that girl a basketball :p

[QuadJunkies]

Originally posted by Livin4Real
The heck with quads, give that girl a basketball :p :p

[Ruby Soho]

yeah, i agree with newnick, she looks plenty big enough and ready to ride/race a 300 or blaster

[elementryder]

holy crap shes tall im 13 and only andout 5' 4-5"
it never to hot or to cold to ride in the moutains i will ride in the det of winter on on the hottest day of the summer it dont matter to me i just deal with the conditions xcept fur when its raining





Originally posted by QuadJunkies
Kelsey said she wanted to show ya some pics of her riding my quad today..She grew even MORE since shes had been on it :(
http://i.pbase.com/g4/26/660826/2/64674963.VYlyRC1d.jpg

http://i.pbase.com/g4/26/660826/2/64674960.u8bDmT0V.jpg

http://i.pbase.com/g4/26/660826/2/64674962.pivSggxc.jpg

I didint get the best pics today,just some quick shotscause it was WAY too hot to really be riding long today.
http://i.pbase.com/g4/26/660826/2/64674955.4Og49FgA.jpg

http://i.pbase.com/g4/26/660826/2/64674954.GQDUgmrY.jpg





she does well on it ...For herSize.. But I got to see 1st hand that she doenst have the muscle to manvuer as well as her other two quads ,mine is also so stinkin wide that on the trails shegot hung up easier .. :p
http://i.pbase.com/g4/26/660826/2/64674953.kHOpF4wR.jpg

[QuadJunkies]

She about that tall too,its just her legs are endless..:scary:
We still plan on the conversion so she can race with kids her own age for another year or so, then Ill turn her loose.:ermm: