Holy horsepower!

[yamaha225dr]

Anyone debating on jumping to a 38mm carburetor on your 250r, don't debate, do it now! I really underestimated this mod. Talking about a jump in top end power, this thing doesn't go flat at all now, it just pulls hard as hell all the way to the red line. If there is a loss of power on the bottom end I can't tell, it revs a lot faster and crisper then before as well but my jetting with the stock carburetor was a little richer then I liked though, so that can be why. I definitely recommend this mod and I still have to install my v force reeds.. Now let me get back to my plug chops. I will probably go through a dozen plugs before I am determined it's not running lean. lol

[yamaha225dr]

This is from my last plug chop.
http://i163.photobucket.com/albums/t294/Dale06_photo/CAM00202_zps244e14c8.jpg

[NeverLift]

Looks to be dialed in perfect.

[keister]

I am thinking about some mods for my 85 R. V Force 3 reeds are definitely on the list. What pipe are you running? Where did you buy the carb and what are they going for these days? What is your jetting at?

Glad to hear yours is running strong!

[yamaha225dr]

The pilot is a little too big cause I had to turn the air/fuel screw out two turns but I will just stay with the 55 pilot, needle clip is in the middle with a 160 main jet. My mods are an FMF Fatty exhaust, airbox lid removed, k&n filter and now the 38mm carburetor. The carburetor came from eBay for $101 shipped.

[MyMistress86R]

What reeds are you running again? I thought I saw somewhere that you stuck v-Force 3s in it. If so, I ran that exact same setup (.030 over stock) with a PJ36 carb and had great success with a .45 pilot and .160 main.

In fact, I am running my new 310 (see sig) with the same carb, pilot and needle position. Only had to boost the main to .185. Seriously considering stepping up to a 38AS on this bike though. Just fear the low end loss since I trail it (2-3 gear at most) 98% of the time. After reading your post though...hhmmmm

[yamaha225dr]

VF3's will be installed soon,. I wanted to do the upgrades separately to feel each of the gains but after dealing with the aggravation of installing this carburetor, I am gonna wait a few days and just enjoy the current power. lol

[yamaha225dr]

I think the low end loss is a myth cause I don't notice any loss if there was any!

[Daddio]

VF3's will be installed soon,. I wanted to do the upgrades separately to feel each of the gains but after dealing with the aggravation of installing this carburetor, I am gonna wait a few days and just enjoy the current power. lol
When you put the reeds in you'll no doubt have to re-jet again.

[yamaha225dr]

When you put the reeds in you'll no doubt have to re-jet again.

And another reason why I am waiting. The stock reeds are still in surprisingly good condition, so it's no rush for me.

[RIDE-RED 250r]

Glad you like it! Told ya didn't we!! LOL! :beer


My former setup was almost exactly what yours is, except I was running different reeds. Mine settled nicely on a 48 pilot jet. Was crisp, didn't load up, but not too lean. Heck my 350 is happy running a 50 pilot.

I'm quite certain your setup doesn't need a pilot jet that rich... Once you dial that it you are going to be amazed at the quickness up through the gears along with reliable running at lower speeds!

High side looks spot on from what I see of the pic you posted...

[yamaha225dr]

Glad you like it! Told ya didn't we!! LOL! :beer


My former setup was almost exactly what yours is, except I was running different reeds. Mine settled nicely on a 48 pilot jet. Was crisp, didn't load up, but not too lean. Heck my 350 is happy running a 50 pilot.

I'm quite certain your setup doesn't need a pilot jet that rich... Once you dial that it you are going to be amazed at the quickness up through the gears along with reliable running at lower speeds!

High side looks spot on from what I see of the pic you posted...


See, that is one thing I was surprised with about the size of my pilot. It is definitely a little bit too big cause my air/fuel screw had to be turned out two turns to get it lean enough but it's not loading up at all and I can lug it down in second gear, hit the throttle and break the tires loose with ease! My stock carburetor was jetted too rich but I didn't realize how bad it was until I stuck this carburetor on and got the jetting dialed in. So, I got a bonus just by getting rid of the crappy jetting. It used to load up real bad and just jumping a 1,000ft in elevation would send it into a sputtering nightmare in the mid range! I just can't get enough of this thing now! It is so much more fun too ride and the smoke has minimized a lot! It used to really smoke a lot until it got ridden for a little while and leak sludge out of the muffler from unburned oil. I really feel stupid now for even riding bit like that.

[atc300r]

I had a set of vforce reeds in my 300r and after not even a full tank of gas they look like this. I bought them second hand with brand new reeds .I put the new reeds in before installing them.The previouse owner only put a couple tanks of gas threw them. He was putting his Fourtrax back to stock thats why he sold them. 171106 171107

[JasonB]

i never had issues with my vforce3 carbon fiber reeds. They ran great on my bike. anyways, i did install a 38mm carb on a buddy's 85R on friday and talk about a difference! I put a 50 pilot and 160 main in his, ran great all sunday of riding with him. Glad to hear yours is working out too!

[yamaha225dr]

Thanks! I ran V-force reeds in my old Blaster and I never has a problem, so I am sure these will last for a long time.

[RIDE-RED 250r]

WOW! That's the first time I have seen or heard of such miserable failure with V-Force reeds! Not that I make any claim of knowing everything mind you....That is very disappointing though.

Oh, and Yamaha225dr, you can do plug chops to check your low speed (pilot) circuit as well. Same procedure, just get it good and up to temp on an old plug, then put a new one in and run it around for several minutes trying to keep it in that pilot jet range at all times.

Sometimes jetting can be confounding and seemingly defy logic. For example, my 250 with the Fatty pipe, dual stage reeds and PWK36 is currently at 160 main, with a 37 pilot...and it still seems like it wants 1 size leaner on the pilot! Take the jetting where your engine leads you.

[Jason125m]

I've been on the fence about a 38. I guess I will search around for a 38 and see if it is as good as everyone says it is.
Which 38 are you running Yamaha?

[RIDE-RED 250r]

I've been on the fence about a 38. I guess I will search around for a 38 and see if it is as good as everyone says it is.
Which 38 are you running Yamaha?


Absolutely! One of the best bolt-on mods you can do to an R in my opinion..... another plus is that carb is very capable on most of the big bores. Leaves you room to grow. I eventually want to get a 40.5 for my big bore to sort of "complete" my build theme. But for right now it really does run good with the 38 AS.

[yamaha225dr]

It's the 38pwk carburetor. I didn't do the pilot test exactly like you described, I just let the trike idle for a long time without touching the throttle and checked the plug after that and it got a little darker but not much.

[RIDE-RED 250r]

It's the 38pwk carburetor. I didn't do the pilot test exactly like you described, I just let the trike idle for a long time without touching the throttle and checked the plug after that and it got a little darker but not much.

Not much real difference between a 38PWK and 38PWK/AS. It's the same carb, just the AS has a couple little fins in the venturi between the slide and intake to supposedly guide the intake charge more effectively. From what I see here and other places, the jury is still out on if it really makes a difference or not....

Well, the pilot jet does have an effect on the idle circuit. But from what I have done, an idle test doesn't give the full picture of how you are running on the low side.

Like I said, just like a main jet WOT plug chop... Do the same thing, but keeping the throttle above off-idle yet below 1/4 throttle. That will give you a much better indication of how well your pilot jet is dialed in. You will notice that you have to run it around at that speed for several minutes though. Running that throttle range takes a bit longer to color the plug than doing a WOT main jet check....

While you are running it at that speed to get color on the plug, pay attention to how the engine is running. Listen carefully for smooth lean bogging if you lay into the throttle a little bit while running the engine on the low side.

My guesstimation is you will get a very dark and wet plug when you do a pilot jet plug chop....If you do, and you end up needing to step that pilot down a bit, you are going to notice even better transition up through the low end if/when you make an adjustment! :)

Make sure and post up your findings!

[yamaha225dr]

Thanks! I will post my findings but it won't be until this weekend.

[yamaha225dr]

Well, I finally got around to tinkering with my jetting again. I dropped the 55 pilot down to a 48 and it's a tad too small, so I am gonna try a 50 next when I get time. I can't tune out a hanging idle with the 48 and it's lost a decent amount of power on the bottom end.

[RIDE-RED 250r]

OK good, sounds like you are making progress...

Hanging idle can be indicative of too lean of a pilot jet as you suspect IF you have conducted a leak down test and are 100% sure you don't have an air leak somewhere.

So long as you have no air leaks, you are certainly on the right track! :)

[yamaha225dr]

I have sprayed carb cleaner around the boots and carb and everything is fine. I have noticed that my float height is a little too high, cause it is slowly dripping out of the overflow line. It's really a tiny amount that only made a puddle about the size of a quarter on the concrete over a two day period. I guess I never noticed it before cause I usually drain my gas after every ride. I know my float is not sticking cause I clean the carb every time I take it apart.

[yamaha225dr]

So, I have the pilot at a 50 and bumped the main to a 162,this required me to drop the needle one notch but it's running great! my reasoning on the main jet change is that I am moving next month and the elevation is gonna drop 1,000ft and the type of riding will be more wide open then I am doing now.

[yamaha225dr]

Some day, I will get a go-pro but for now, the good old cell phone will have to do. I wasn't planning on dusting my phone but it was either that or run it over. lol

https://www.youtube.com/watch?v=xuFM2erOm-o&feature=youtube_gdata_player

[barnett468]

Hello yamaha225dr




I have noticed that my float height is a little too high, cause it is slowly dripping out of the overflow line. It's really a tiny amount that only made a puddle about the size of a quarter on the concrete over a two day period. I guess I never noticed it before cause I usually drain my gas after every ride. I know my float is not sticking cause I clean the carb every time I take it apart.


One should always adjust the float level first because it affects the jetting. If you jet first then adjust the float the jetting will change. High float is richer, low float is leaner.


TRUE GAS LEVEL TEST -

1. Take a 12" piece of clear tubing and connect it to the bowl drain fitting

2. Hold hose close to carb with open end even with carb top.

3. Turn gas on

4. Open bowl drain screw.

5. Gas will fill tube to level of gas in bowl.

6. Level should be from even with bottom edge of carb wgere it meets bowl to 3/16" below bottom of carb.

[barnett468]

Hello


Spelling correction, "wgere" should be "where".

I have no edit button.

[yamaha225dr]

it wasn't my float level, the o-ring on the main jet access bolt was worn out letting gas seep through.

[RIDE-RED 250r]

Looking at the vid it sounds like you certainly have no loss of power down low! :)

[yamaha225dr]

That was a second gear launch also!

[yamaha225dr]

Nice thread on fine tuning a carb so many times you get people too afraid to talk jetting cause of melt-down ! I run a 39 PWK on a 250 port-polish (little big) V-force3 esr pipe no box and i like to pay attention air temp. and elevation ! I think i got a 160 main in now......careful those jetts snap easy !


What is the elevation where you ride? I wish there was a decently priced fuel injection kid you could buy to ditch these carburetors! It would sure make jetting a lot easier, if you knew how to adjust the fuel trims.

[barnett468]

Hello


There is a company that makes an altitude compensating kit that easily adapts to a carb. They are often available on Ebay for around $100.00. Many of the Pikes Peak racers use them. They are sometimes called Vari jet.

[yamaha225dr]

Hello


There is a company that makes an altitude compensating kit that easily adapts to a carb. They are often available on Ebay for around $100.00. Many of the Pikes Peak racers use them. They are sometimes called Vari jet.


Yea, I know it by "Dia-A-Jet" unless the company has changed names or its a different one.

[barnett468]

Hello




Yea, I know it by "Dia-A-Jet" unless the company has changed names or its a different one.


That's it, couldn't remember, thanks.

COMPRESSION RATIO - There is a loss of 5 psi cylinder cranking pressure for every 1000 foot increase in elevation so if one goes from 160 psi cylinder cranking compression at sea level it will be 135 at 5000 feet in which case it could be compensated for with a higher compression head or thinner head gasket etc.

[keister]

Thanks to this thread, I was inspired to make the jump. ATCtim and I installed V Force 3 reeds, PWK 36 mm, and ESR5 pipe today. Hardest part was streching that big stupid intake boot. Now I have big power all over the rev range- especially the midrange. Great call. Lovin it. A few quick bolt ons made all the difference in the world!!

[yamaha225dr]

I bet with those mods all done together you really had a nice boost in power! The initial installation is the hardest but the rubber boot will stretch and make fitment a breeze.

[keister]

It worked!! I finally got a nice test ride on it at Ashtabula Pine Lake Nationals over the weekend. The R just screamed down the straightaways and almost pulled me a holeshot in my B-class heat race. Once again, thanks for the inspiration in this thread. Now, if I can just find a way to catch that pesky Yamaha.

[yamaha225dr]

Good deal! I haven't gotten to ride mine in a couple weeks, I have been busy getting ready to move.

[roonie]

could i do this mod to my Big Red 250es or are they different. thanks

[RIDE-RED 250r]

could i do this mod to my Big Red 250es or are they different. thanks


No, that carb is way too big for a Big Red.