ESR 38mm AirStriker quesion...

[nathan89]

I'm going to buy a new Keihin 38mm AirStriker from ESR and I see that they offer an option to machine the carburetor ends to a smaller size so that they will fit into the stock intake boot and airbox. My question is there any negative to having this machine work done? Does it effect performance or make the carb fragile from the material being thinner? thanks for any help.

[Grande Huevos]

no it does not effect anything at all. the material that is machined comes off the outsied. The actuall inside diameter stays the same and no it will not make it weaker either, ur carb doesnt really get any abuse anyways. I just got one from them couple months ago and had this done. Fits like a glove !!

[DnB_racing]

the only very small issue is your still using the stock size intake, with the larger obviously there is a slight different flow, Im not sure how much difference in cfm's? but there must be a little difference.... but thats just my opinion. I could be way wrong?

[Ruf Racing]

Correct me if I'm wrong, but I don't think the mod is necessary. You can heat both intake tubes, with a little manipulating. The will slip on the carb. Yes, no?

[DnB_racing]

Originally posted by Ruf Racing
Correct me if I'm wrong, but I don't think the mod is necessary. You can heat both intake tubes, with a little manipulating. The will slip on the carb. Yes, no? depends on the condition of the boot, sometimes they are so dry and cracked its not worth tying,
but if still ply able they can be heated and fit, mine was too far gone,i went with a new larger one ,
I forget the brand, but its made for the larger carbs,

I really dont know if the larger size will make any performance gains, but I would think it would be a little like adding a spacer torque plate, but Im just guessing!!

Im interested in the answer if anyone knows?

[Grande Huevos]

heating them up would prob work but wouldnt u have to do that every time u took the carb on and off? and i would think the mod would still b a little easier to work w then the heating way? not for sure never tried it. As for the flow issue i dont see how it would b diff because the carb fits inside the boot not vice versa right? Also on the same note if it was a diff size couldnt u cut/carve the inards out a lil to make it bigger? There is a thread somwhere on here talking about intake boots and somthing about certain years of cr boots u have to cut the inside out and make it smooth to cut down on turbulance to deliver smoother airflow. I think the diff would b in the boot at the front of the carb not the intake anyways? example when u buy the air box eliminator kit i think u can get a larger boot or have the metal tube machined to make the inner diameter bigger if it doesnt come that way. Im not positive on this but that would be my understanding.

[nathan89]

thanks for the comments guys. i went ahead and ordered the carb with both ends machined. figured it was worth the little extra money to have an easy fit and not have to heat the boots. and it's good to know the carb wont be paper thin or anything after the machine work. i will post a couple pics when i get it.

[danhung11]

I could have sworn the ESR piece was an adapter that was separate.

Could you post some pics when you get it?

Thanks,
Dan

[250Renvy]

Upp racing makes a boot that is larger for larger carbs.

[rayman375]

Originally posted by danhung11
I could have sworn the ESR piece was an adapter that was separate.

Could you post some pics when you get it?

Thanks,
Dan
ESR did make an adapter, I bought a 38as from KSRider that has one on it. Maybe they are machining the actual carb down now though? I would like to take the adapter off the carb that I have but it seems to be on there pretty tight, don't know if I can get it apart or not.

[danhung11]

Originally posted by rayman375
ESR did make an adapter, I bought a 38as from KSRider that has one on it. Maybe they are machining the actual carb down now though? I would like to take the adapter off the carb that I have but it seems to be on there pretty tight, don't know if I can get it apart or not.

That's the same one troybilt has on his new Laeger, it's pretty slick. I just wanted a picture of a machined carb...

FWIW... the stock boots work, you just have to wrestle it on there. If it's a weird angle, try a CR250 boot. It's shorter and has a sharper angle.

[Grande Huevos]

Originally posted by danhung11
That's the same one troybilt has on his new Laeger, it's pretty slick. I just wanted a picture of a machined carb...

FWIW... the stock boots work, you just have to wrestle it on there. If it's a weird angle, try a CR250 boot. It's shorter and has a sharper angle.

I have the 38 as from esr both ends machined and use the cr boot not sure on year but it fits awesome. Im also not sure how much they take off the carb but it doesnt really look to diff to me. I will post some pics up of mine tom evening.

[Grande Huevos]

Pics of a machined carb from ESR. I dont kno how to add pics directly to the thread so here is a link to my photobucket.


http://s1222.photobucket.com/albums/dd493/jakes2c/machined%20carb/

[nathan89]

^^^^ looks good, thanks for the pics.

[deathman53]

I have 38 and 39pwk's on trx and atc's. For the trx, buy a new 86 tube, you can easily find them on ebay and places that warehouse parts(ie: east coast atv). Its soft and very doable, no wresting needed. If some work is needed, you may make fun of me for this......but it works.
I found that a regular sized bottle of beer is somewhat larger than the bell on a 38/39 carb, on one atc, I heated the last 4 inches of the end, slid the beer bottle in from the tapered end and worked it until it fit, I left it alone for some time. Removed the bottle, put the tube on the carb(slid right on), clamped it and connected the other end to airbox. On the trx's(w/ new tubes), I worked it w/ beer bottle, slid carb on and it was simple.

[nathan89]

great idea... gives me an excuse to ''need'' beer!