Keihin vs. Edelbrock

[jasonp]

I don't really understand half the stuff jason and griff said, but for some reason I want to get a CV carb for my Warrior.

The warrior comes stock with a CV carb.

 

[97warriorrider]

[quote:cd3ejzuu]I don't really understand half the stuff jason and griff said, but for some reason I want to get a CV carb for my Warrior.

The warrior comes stock with a CV carb.[/quote:cd3ejzuu]
O man thats good ****

 

[griff]

LOL!

 

[griff]

Heres a copy of the post I think Jason was refering to:

Velocity and volume are whats important.... velocity alone will not "make more power". Its a balancing act, just like with head-porting: You want best possible velocity that also allows complete cylinder filling (i.e. not too much, not too little). Its an exact science.

The stock CV carbs on the 350 is actually pretty damn good, it has a wide tunable range. It is not "restricted" in anyway other than the jetting and the airbox its attached too. The butterfly valve in the primary (venturi) is a standard design component for most CV (Constant-Velocity) carbs, its necessary as to maintain proper vacuum control against the slide.

Remember the slide is vacuum actuated, you turning the throttle does not open the slide (you turning the throttle controls the butterfly), vacuum within the carbs system raises or lowers the slide. That is the point where air/fuel metering is determined. The butterfly allows the vacuum from the engine to ramp-up in a controlled/measured rate.

Flatslide carbs have no butterfly (doesnt need one), the throttle cable is connected directly to the slide itself. This is also why an accelerator pump is usually (but not always) necessary, when you whack the slide wide open, there is for a moment, insufficient vacuum generated by the engine (rpm's have to build 1st) to pull fuel from the various fuel circuits. The accelerator pump basically fixes that.

Flatslides are good for faster throttle response and top-end, but they do tend to lose bottom-end and mid-range power/torque. They are also thirstier with fuel. Theyre great for drag racing or dunes.

CV's are much better for bottom-end and mid-range power/torque, they flow decently at the top-end, but not quite as well as flatslides. CV's are much more fuel efficient in general. Great for trail and XC

Theres always a trade-off guys, just have to figure out which side of things suits your taste and riding style the best.

36mm is on the borderline of being too large for the stock 350 engine, probably about perfect for a 366. Do not go to larger carb unless youre running a large displacement stroker or similar setup. Theres no point, and you will not make "more power".

Hope thats it...

 

[jasonp]

hahaha
I know putting this Flat slide on it made the bike feel more like a two stroke.

 

[teamexileracing]

Thanks guys, im reading over all your stuff now. Its all confusing to me but im sure ill be able to make it out if i read it a couple times.

 

[chad021]

http://www.procycle.us/carb/mikuni.htm

thats where i purchased my mikuni carb from

 

[madcow]

My stock carb has a slide directly linked to the throttle. Which stock carb was Girff referring to?

 

[dswwarrior350]

Mine also. I dont believe the stock carb works off of vaccum. However i could be wrong. But tehre is no diaphram in it.


This thread is plain and simple and to put it in easy terms.

Dont waste your money on a cheaper carb because thats exactly what you will get... the extra 50-100 dollars spent on the edelbrock is well worth it. The edelbrock has a completely diffrent shape as apposed to the others not to mention a hatched finish on the inside which helps atomize the fuel. The edelbrock is an oval... smaller which creates more velocity, and the hatching. No other carb out there that ive seen for the warrior has those same features. But all in all the stock carb isnt terrible. No matter what you buy your going to have a stumble if the throttle is stabbed, even with my edelbrock although very slight, its still there slightly. But even in 6th gear i can pin it and it will pick up eventually. When jetted spot on no other carb is really going to give you a huge gain. The edelbrock just has its advantages... one single fuel circuit, no worries about losing throttle over jumps and bumps as it has a slosh plate in the bowl. Able to be fine tuned with no tools (with the exception of a needle change and the accel pump which should never need to be adjusted on the trail anyway, even if the pump is way off you should have no problems riding and there is enough needle adjustment to compensate for about 3 needle clip jetting sizes when compared to the stock carb at least)


Just my oppinion... stay stock or get an edelbrock.... not that the others wont give you a slight gain..but its just not worth it imo.

 

[griff]

My stock carb has a slide directly linked to the throttle. Which stock carb was Girff referring to?

Stock carb on which atv? Should be a CV carb for Warriors. By your description you have a Flat-Slide. Is there a butterfly valve in the carb throat?

 

[jasonp]

My carb is just as easy to tune as an brock and gives more performance.
Where is the choke on the brock?
There is a diaphram in the stock carb.

 

[dswwarrior350]

You still have jets and seperate fuel circuits. The edelbrock has no choke because it doesnt need one. Few flicks of the throttle throws plenty enough fuel to it to start it in cold weather as long as the accel pump is adjusted right.

I havent had a stock carb in a while so i dont remember, i never remember it having a rubber diaphram though... and i changed the needle clip a few times.

If fact now that i think about it there is no way its vaccum. There is an arm that pulls the slide up, i know because when i went to changed my clip position i had a hell of a time getting those damn bolts out that connected it. Not that i know alot about carbs... but its nowhere near the same as the carbs on my streetbike and they all have diaphrams and are complete cake to change needle positions. Okay it does have a diaphram in it... but the slide isnt operated off of a vaccum is it? Would that mean the butterfly is?

Here's the edelbrock picture just for reference.

 

[griff]

Its definitely a flat-slide type design. If you pull the throttle, and the slide follows it up and down, its a flat-slide basically. A lot of flat-slides dont have chokes either, so thats not unusual.

Edel does have a little different way of doing things, but ultimately the same basic design principles apply. They make a very good carb, of the ones I've opened up, they were VERY nicely built.

 

[griff]

Geezus, I'm trip'n.... For some reason I had it in my head the Warriors had a Mikuni BTSS, then after some of your guys comments, I checked and see its a BTM. Guess this Dr. Pepper is stronger than I thought. Sorry for the confusion guys!

 

[jasonp]

Can someone please explain to me the tuning of an brock carb? Like to change the main jet on mine I would have to loosen up the main jet plug on the float bowl and it's right there. Don't even have to take the carb off. For the jet needle you have to turn the carb and then take 3 bolts out the top. Then the allen head that holds the screw in. The pilot circuit is done by an air jet which is on the outside of the carb or the pilot jet which is in the float bowl. Fuel screw of coarse is on the out side. The accel pump is right on the side of the carb as well. I guess the fact is to you really don't go changing a bunch of jets around after you get it tuned in. I would say though that people have a hard time with this part of it and give up, and move on to something simpler?

 

[jasonp]

i think the hatching you are talking about DS is more for that fuel droplets don't fall out of (suspense) the air and stick to the carb or pool up. This hatching or marking creates a bearier inbetween the side of the carb and airflow flowing past like how you don't want to polish you intake manifold as fuel will tend to pool up.

 

[dave76]

[quote:mhh7k85j]I don't really understand half the stuff jason and griff said, but for some reason I want to get a CV carb for my Warrior.

The warrior comes stock with a CV carb.[/quote:mhh7k85j]
I thought the Warrior came stock with a flat slide?? It def has a butterfly after the slide.

 

[jasonp]

[quote:g9u3xm8i]

The warrior comes stock with a CV carb.

I thought the Warrior came stock with a flat slide?? It def has a butterfly after the slide.[/quote:g9u3xm8i]

Constant Velocity carbs have a buttery fly and a flat slide that is vacuum operated to help keep the speed of the airflow the highest through the carb to help make more torque at all rpm ranges.

 

[griff]

OK, you guys lost me....

Does anyone have the carb schematic for the Mikuni BTM? Last time I looked at it, it appeared to be a typical flat-slide, i.e. no vacuum actuation.

 

[griff]

OK, heres a schematic of a BTM from a '99 Warrior:

Looks like a typical flat-slide... No evident vacuum system, no butterfly in the carb venturi that I can see. It does have a side-arm actuator for the slide from what I can see, which isnt too unusual. Some TM series carbs had it right on the top though IIRC, at least the one I put on my old DR did.

Hehe, that the problem with Mikuni carb designations, they can be a little weird sometimes. Though I have seen some manufacturer specific carbs made by Mikuni that are pretty weird design (like the Mikunis on the 1st gen Yamaha FZ1).