CR125 INTAKE

[blaster88guy]

i read on the blasterhq fourm that a cr125 intake will work on a blaster motor and if this is true is it possible to hook a boost bottle up to it, thanks

[MXRACER708]

inever heard of that

[blaster88guy]

yea a guy on there said they have the same bolt patterns and you can get them on ebay really cheap, and he said they look just like sms intake

[waltnuts42]

this is credit from kartracer92 on cp customs forum.



That’s pretty much the understanding that I got when the mod was described to be by many But I am going to give ya all some facts, opinions and measurements here shortly


Measurements :

1. The stock blaster intake opening is 2.178

2. The intake surface face is .200 with apox a .032 lip leaving the intake wall thickness .168

3. The intake trac depth from surface to the tallest point on the intake bridge is 1.713

4. The total width of the cr-125 reed cage is 2.360

5. The total depth of the cr-125 reed cage is 1.775


Measurement/grinding facts

1. After grinding the intake and clearenced for the reed cage each intake wall will be width of .091 and in finish maybe smaller.

2. In order for the reed cage to fit depth wise. .044 material would have to be taken off the intake bridge. To avoid thinning the walls deeper and removing material from the bridge the addition of a reed spacer would be the best solution.
Of coarse the spacer would have to be side clearenced too.

3. Intake side/wall surface is .091


Conclusion:

1. I felt that the intake walls were getting dangerously thin and I stopped before completed and decided to opt for a solution and a better alternative.

2. I didn't have any experience or facts of how much heat that the intake area endured and with the addition of the weight of a bouncing carb I didn't know if distortion and cracking or both might be a possibility.

3. I decided that I was going to fabricate some alum flat stock to the outside of the intake walls and heli-arc them for strength before I finished the final fitting of the reed cage while I still had material to weld to and with.

4. If I would known in advance and researched this a little further I would of started with the addition of the added reinforcement to the intake walls.

5. I personally didn't feel that this mod was a simple as many said it to be. And I think a in-experienced person without measuring tools and some facts could very easy find their self in a bad position





and this is credit from yamahafreek at cpcustoms forum also.



the best route will be to remove half of the thickness from the reed cage sidewalls, then sand and fir the reed pedals accordingly (milling machine will make short work of this


by adding a reed spacer nothing will need to be removed from the intake bridge, this has other benefits as well.... increased crankcase volume,releases the charge further back enhancing throttle response it also allows a better flow path into boyesen ports (if you are adding them) also allows a clearer shot to the boost port


i have done this to khefts and a few other cylinders, i can shed some light on what the best approach is ( at least what has worked for me)

by the way the end result is roughly 20% more reed tip area= more top end flow with minimal loss of bottom end response

[kartracer92]

Walnuuts thanks for passing the info on and I am glad somebody can get some use from it.

The Cr-125 manifold is a direct fit and the exact bolt pattern as the blaster stock/bolt pattern.

However the blaster intake area will take some modification for the cr-125 reedcage, in the end I did not rienforce/weld any extra material to the outside of the intake area. Although it is thin and I used yamabond to seal the reed spacer the mod is fine and I have had no trouble what so ever.

This proved to be a very good mod. The cr-125 reedcage is a six petal reedcage and adds about 20% more area to the blaster. The most attractive thing about the mod is a cr-125 reedcage/manifold can be purchaced for as little as $25.00 used and some of your own labor at no cost vs your option to a aftermarket reedcage/manifold that will set you back just a little under $200.00 depending on the manufacture that you use.

I can assure you that this mod is everybit as effective as the aftermarket cages/manifold and for the amature/recreational rider you would never measure the difference/performance between them.

I am surprized that this mod has not caught on more than it has, it only makes dollar sence. The cost saving alone could allow you to put your money spent on costly reedcages/manifolds toward a port job for those of you that don't have the resources and knowledge to do your own port/head modifications.

Jeff

[yfsrider]

im about half done the grinding needed to make my cage fit, i was able to aqquire my cage and manifold off of ebay for $14.98 it was off a 98, a little dirty but in good shape. ill be sure to post up some pics when shes done

[blaster88guy]

i got an intake and reed cage for 15 shipped on ebay and the intake is a direct fit to the jug and i got a cr125 carb for 36 shipped on ebay so i payed 50 for a 34pj carb and an intake that look identical to the sms intake, so if ur looking for a cheap intake set up search for cr125 on ebay and u will probly find a good deal

[blasta13]

sooo, what all works? my brother just took off his reed cage from his cr-125. will that fit? i dought it

[kawi]

You have to make your intake walls pretty thin,

Id go with g3's myself,

But youll save alot of moeny doing the cr125 intake.

[jeffdunn45]

wait.... soo if i have a reed spacer i can just bolt it rite on??

[kawi]

No,

U have to widen the intake walls, and do everything else Kartracer said.

[jeffdunn45]

screw that... i think im mechanically retarded.. id save more buyin the aftermarket cage than the money i would save using the cr125 cage because of the damage i would do ... lol

[blasta13]

i think im just gonna get a v-force 3.

[kawi]

jeffdunn45 said:

screw that... i think im mechanically retarded..

lmao

[kartracer92]

I encourage you who don't self educate/improve and do more of the DIY mod's, it is a learning curve but much is to be said for saving & performance

Example :

I recently finished the following mod's on son's blaster and did all the work myself with the exception of the bore.

1. aggressive/trail port w/ aux intake ports
2. decked cylinder .065
3. cut & rechamber head (17cc)
4. lighten flywheel (7 oz)
5. modded intake for CR-125 reed cage
6. install 34pj carb/intake
7. added 400ex rear shock
8. Built/faricated +3 ( chromoly round tube swingarm)
9. advanced timing ( stator plate)
10. swingarm roller bearing kit
----------------------------------------
1. porting Free
2. rechamber/cc head Free
3. boring fee 50.00
4. piston kit 75.00
5. cr-125 reedcage(used) 25.00
6. pj-34 carb (used) 55.00
7. chromoly tube 40.00
8. bearing kit (swingarm) 36.00
9. Fabricate swing arm Free
10. advance timing Free
11. lighten flywheel Free
12 head/base/spacer gaskets 15.00
13. deck cylinder Free
14. 400ex shock ( cut head for it)Free
----------
$296.00

Tusk nerf bars 99.00

holeshots 18x8 rear
w/douglas rims 141.99

Holeshot 20x6 front
w/douglas rims 151.99

14T sprocket 15.99

520 chain 76.00

motion pro twist kit 36.99

--------
521.96


Original cost of 2001
used blaster 1200.00
------------


Grand total of blaster/parts/ mods $2017.96


At the cost of labor/parts for the entry level blaster that carries "no" resale value and worth DIY mods are really the only practical way of having a modded blaster.

In a few short weeks I will add an additional "money free " mod by stretching the blaster frame and adding some handling, specs by "phragle" and finishing the coustom modded touch and a blaster complete under 2500.00 dollars...not bad