keihin 38mm carb questions

[1998yamahawarrior]

Ok Ive found what I think is a decent deal on a keihin 38mm carb for a warrior. I know its bigger than the stocker. Heres where the questions come in. Are there any down sides to this carb? How hard are they to tune? And last but not least how much do you think a used one with the jug to carb boot is worth as long as it is in working order? Thanks guys!!

 

[duneracerweston]

Is it a flat roundx or moon slide? Does it have a buterfly valve in the intake? Is it a bolt on like a warrior or is a clamp on like the rappy? And lastly dose it have a accelerator pump?

 

[1998yamahawarrior]

No butterfly valve from what I can tell in the pics, its clamped to the boot, dont know about the pump as Im still emailing the guy. Not to mention Im not to familiar with these carbs. Heres the pics he sent me of it.

 

[duneracerweston]

If your building it for low end torque that's perfect round slide no accelorator pump but that things got such a short intake its not going to wanna fuel right above 8k and its not going to be a really clean burning carb its really easy to tune not much to it but it looks like it came off a 2 stroke which is fine

 

[duneracerweston]

Btw ask for 2 more pics one of the outside of the carb that's not shown in the pis above and one pic of the inside the carb from the motor side without the throttle slide that will tell a lot about the carb

 

[1998yamahawarrior]

Ok thanks man Ill see if anyone else has anything to say about it before I go any further. Im trying to plan out the biuld for Jar-Jar and if I can find some decent deals I might go bigger than originally planned.

 

[duneracerweston]

Are you gonna p&p? And see if he will give the demensions of the carb like od of both the intake side and motor side and legnth from motor side flang to air box flang you might be able to put a rappy intake on it and fix the high rpms and bake it run smoother and cleaner but the way that carbs built you don't even remove it frome the bike to jet it !! Just take that big nut off the bottom and get a 90 deggree flat head or like a 5/16 socket and presto you got the jets out of it

 

[1998yamahawarrior]

Ya at least a mild P&P is planned, along with probably a .390 cam and either bored to the .040 over the jug I got from blkblzr or take that jug to a 366. If this style a carb is a really good mod I may see if I can find a different one.

 

[duneracerweston]

The stock carb is stuffed up only 36mm and that butterfly takes a ton of space so tthis carb will flow a ton better eather way you go with the motor this carb will do awsome it will rev real smooth it might be a tad jumpy and its going to have a little stiffer thumb throttle running that carb I run the mikuni version of this carb and I love that sucker it never quits pulling its horrible about spinning the tires and diging rutts so its not going to handy cap it any

 

[1998yamahawarrior]

I wonder if a Dial-a-jet could compensate for no accelerator pump?

 

[JonS]

i believe that's the one duncan sells. it the same one i'd like to get as well. if you get a good deal then snag it up.


btw, why is it that one would need an accelerator pump? lots of ppl run carbs w/o them anyway.

 

[duneracerweston]

i believe that's the one duncan sells. it the same one i'd like to get as well. if you get a good deal then snag it up.


btw, why is it that one would need an accelerator pump? lots of ppl run carbs w/o them anyway.

Accelerator pumps help when your going from a high idel (arond 2000 rpm) to WOT it keeps it from laging by squirting fuel intgo the intake so that it dosent have a momentarly lean burn and runns correctly but you won't hardly notice its gone on this carb

 

[1998yamahawarrior]

Ok now that clears a few things up. Thanks. Next question, the guy doesnt have the throttle cable and like I siad Im stupid when it comes to these carbs setup. Would this cable be what I would need: http://cgi.ebay.com/ebaymotors/MOTI...rcycles_Parts_Accessories&hash=item35b1e9caf4

 

[1998yamahawarrior]

The one I posted up there would be for a twist throttle. Heres one I found for a Thumb throttle, but it is for a Blaster. Would it be close to the same length: http://cgi.ebay.com/ebaymotors/Moti...ors_ATV_Parts_Accessories&hash=item2c5cbbb975 . Really contemplating this.

 

[paulie1959]

I dont think youl gain any performance on this carb.(38mm round slide no acc.pump 1970 vintage) ther are a lot better carbs out there. the best carbs for 4 stroke performance you need a acc. pump and flat slide like the keihin fcr37mm, even the 400ex carb is a upgrade(38mm flat slide acc. pump), And to make the 38mm perform better, the stock 36mm warrior port needs to be inlarged and you need a +1mm intake valve installed. Im now trying to install a FCR 37mm off a crf250 on my Raptor 350.

 

[1998yamahawarrior]

Well now I have points of view from multiple people, what I need is someone that is for sure. I dont want to dick around with a carb swap if I cant get for sure. Though this or any other carb(unless I found an Edelbrock) will not get put on til I do my motor biuld.

 

[duneracerweston]

Its a nice carb go on motion pro look up warrior then look at alternent cables id do it and post a link butg I'm using my phone that's a great carb for torque but not allout hp its good for woods and more like a low end carb but works good for the topend a accelerator pup is only hepls troughtle respoce not power and that's not a 70s carb I still say if he will give you the demesions of the carb and its flanges then we can know if it will fit

 

[1998yamahawarrior]

Im pretty sure its the kit that Dennis Kirk sell, just missing a few pieces, not any of the vital part though. Here a link to the DK kit: http://www.denniskirk.com/jsp/produ...catId=&productId=p16259&leafCatId=&mmyId=6566

 

[duneracerweston]

That's a DG but it looks a ton like the one you ve got here

 

[1998yamahawarrior]

The guy is advertising it as a DG carb. Obviously DG doesn't make carbs so I think it was a kit they put together.