ESR Reeds and pump gas head?

[yamaha225dr]

I am finally to the fun part of my 250r phase. That means more power, although I don't think it's lacking any but more is always better right? lol I am just gonna do a few small things right now and know the reeds are a nice upgrade but what about the pump gas head on a stock engine? I will eventually have it ported but not until a rebuild is needed. Is it a nice upgrade all by itself? I would like to do the ignition upgrade but I am not ditching my lights, so is there another similar upgrade to keep my stock stator? Thanks!

[RIDE-RED 250r]

OK, firstly and according to my HONDA shop manual, a stock 250r engine should have 92-100 octane fuel run in it.

Having said that and assuming your head/cylinder has not been played with you should be fine to run straight 93 oct pump fuel...To find out what octane fuel you need to run, a quick compression check will give you a clue. But determining your un-corrected compression ratio (aka: UCCR) will tell you for sure.

Secondly: reeds of different brands do not have an effect on the minimum fuel octane requirements of your engine. Reeds generally do not increase overall power by any significant degree.. At most they can have an effect on what RPM range your peak power will be made in. They are just one of many components in the overall build theme of your engine....

Thirdly: Ignition upgrades... Without going with the '01 CR250 digital ignition upgrade, about the best you will be able to do is replace your CB carrier with a CB carrier that has adjustable ignition timing. The pulse generator is mounted to the CB carrier and the OEM 250r carrier does not have provisions to adjust the position of your pulse generator (which is how ignition timing is controlled on a 250r). I believe RPM offers and adjustable timing CB carrier and for under 100 bucks. Just be careful and know what you are doing before playing with your timing. You can end up damaging your engine if not properly jetted and or running higher octane fuel if you advance the timing too much.

Stay away from aftermarket CDI units! OEM only!

Fourthly, porting.. YES, porting is a significant mod that will net you serious seat of the pants improvements in your engine's performance. My ESR engine is ported for mid-top and the way that thing comes alive when you get on the pipe good and hard is just mind blowing compared to my other R that is a stock ported cyl with pipe, carb and reed upgrades...

There are several good shops/people out there with stellar reputations for porting 250r cylinders. Do your research and make that decision for yourself. Just make sure you have it done by someone who is known for doing good work on the 250r. You can easily destroy the performance of your engine by doing a custom port job incorrectly.

I already know who I will be having port my 250 next winter! Can't wait!

[MyMistress86R]

What he said but I'm not certain I actually understand the whole depth of what you were getting at. No offense ride-red, but that was one hella in depth reply to a somewhat basic and slightly cryptic post...

Reeds will help, but as stated, it's all about where they help.

A pump gas head on a stock engine? Aren't they all anyway?

Porting is good...very good when coupled with proper intake (reeds) and exhaust, suited to match your port job. And I agree, the port-er matters. Have it done by someone reputable and 2-stroke knowledgeable.

And why do you want to change your ignition? Did someone tell you that you should? I've never had mine hold me back AND I still have lights.

[yamaha225dr]

Sorry about the confusion guys. I know reeds have no effect on fuel octane, I was asking about the ESR brand pump gas heads and whether it is a decent upgrade with the stock bore and stock porting, if not what about one that will require race gas or a 50/50 mixture of pump and race gas? I always have Sunoco 110 race fuel on hand. As for the ignition, the stock one does work fine but the CR ignition upgrade is supposed to be a nice upgrade over the stock one due to the timing change and I think the flywheel is lighter also but I gotta refresh my memory. It must be a nice upgrade when ESR offers the whole kit on there website! Thanks!

[RIDE-RED 250r]

No problem MyMistress, I was just trying to answer what I figured his questions were as thoroughly as possible.. :beer


Yamaha225dr: IMHO, an aftermarket head alone is not going to be a big bang for your buck part. If you want to set up your engine to run on race fuel, you can simply run the thinner CR head gasket... Pretty sure it's the '85-'86 CR gasket, someone who knows for sure please step in and confirm or correct me on that.

Yes, the CR ignition is a heck of an upgrade. I have not done one yet myself, but I hear from dozens of other R owners and many say it was pretty close to the best money spent on their machines. IDK if I ever will do one myself as I need my headlights...

If it were me, and the engine is all stock, there are quite a few other things I would spend my money on long before an ESR head for my stock engine. I would look to do exhaust, reeds, and 38mm AS carb with the oversize intake boot available through ESR and other sources... Exhaust and/or carb will give you way more bang for the buck than just slapping a head on.

I have basically a stock 250 in my second R I built over this past winter. I have no plans of replacing the head with anything aftermarket. It currently has full FMF exhaust, PWK36 carb and dual stage reeds. Next winter I plan to do a ported 265cc stock cylinder and stock head and maybe a PWK38 AS carb if I get around to picking up a 40.5 for the big bore!

[yamaha225dr]

Thanks Ride Red! That is the answer I was looking for and I already have an FMF exhaust, so that is out of the way. Any specific brand of carb?

[RIDE-RED 250r]

A Keihin PWK38 AS, aka 38mm Air Stryker is a great carb on a stock topend when used in conjunction with good exhaust and reeds. And an added plus is that it leaves you room to grow if you ever decide to start looking into big bores.

[yamaha225dr]

A Keihin PWK38 AS, aka 38mm Air Stryker is a great carb on a stock topend when used in conjunction with good exhaust and reeds. And an added plus is that it leaves you room to grow if you ever decide to start looking into big bores.

I was just looking at that carburetor on ebay! Thanks!

[RIDE-RED 250r]

Don't forget to pick up the oversized intake boot for it. ESR gas them for around $70. I just tried to put my 38AS into a stock intake and not only is it way to small, but the angle is slightly different making the bigger bodied 38 not want to fit where it should go and hit the kicker housing of the clutch cover...

It will be money well worth spending for easy carb installation. And FYI, ESR does offer machining option as well. Personally I would get the UPP intake and have the machining done for the airbox end. http://www.eddie-sanders-racing.com/product_p/38mm%20airstryker%20keihin%20carbs.htm

[yamaha225dr]

Don't forget to pick up the oversized intake boot for it. ESR gas them for around $70. I just tried to put my 38AS into a stock intake and not only is it way to small, but the angle is slightly different making the bigger bodied 38 not want to fit where it should go and hit the kicker housing of the clutch cover...

It will be money well worth spending for easy carb installation. And FYI, ESR does offer machining option as well. Personally I would get the UPP intake and have the machining done for the airbox end. http://www.eddie-sanders-racing.com/product_p/38mm%20airstryker%20keihin%20carbs.htm


Yea I plan to use ESR for everything I get. For now I am just gonna get the carb, oversized boot and reeds. When it's time for a rebuild I will get one of there top end kits with port work but I don't plan on going too extreme. I just wanna be able to run with the new quads on the trail. I haven't ridden with any 450 or 700cc quads yet, so I don't know how my trike stacks up against them right now.

[RIDE-RED 250r]

Big bores are FUN! (don't ask me know I know :naughty:)

One recommendation on the big bores. If you want bolt-on with no case machining I would go with the 310. They offer a 330 bolt-on, but there is something about not having a cylinder skirt that doesn't set well with me. Maybe that's just me... If you want a 330, go with the case machining for the true 330.

If you call Tom at ESR, he will usually put together a special deal of some kind. When I built my 350, I got the 350 kit, mod-top porting, full ESR ATC exhaust, ESR reeds, case machining and crank bearings and seals. Since I called and had a pretty significant order I basically got the reeds and case boring for free. Think I paid somewhere just north of $1400 for all of that. I would have to check to be sure of the numbers... Bottom line is it's always best to call them when you want something.

[yamaha225dr]

How do you keep the front end down with so much power? lol I catch hell right now with basically stock power trying to keep the wheel down but I am a lightweight also.

[09RappySE]

How do you keep the front end down with so much power?

Sit on the handlebars.....:lol:

[RIDE-RED 250r]

How do you keep the front end down with so much power? lol I catch hell right now with basically stock power trying to keep the wheel down but I am a lightweight also.

Being that I still have a stock swinger it's pretty much impossible if there is good traction. You can have your beanbag bouncing off the fuel cap and it will still snap the front end up every time you try and hammer the happy lever!

But most of my riding is on gravel roads where traction isn't super grippy. On that it will spin the tires in 4th gear no problem. Almost feels like the clutch is slipping. I want to try some Holeshot HD's for better traction on gravel...