Accelerater pump Carburetor
 

http://www.chinariders.net/picture.p...609535&thumb=1

Just got this today! It is a carburetor with an accelerator pump. I ordered it from aliexpress. I will be putting it on my Apollo 250 with the Zong engine. I will document it as I go and post pictures of the procedure.

Sorry the picture is sideways.

PowerZone PZ30 IRBIS TTR250 Tuning Tuned Power Jet For Keihin 30mm Carburetor + Visiable Twister + Cable + Repair Kit+grips


https://www.aliexpress.com/item/KEIH...95aed01dbcdb6f



This is the description from Aliexpress. All of this for about $43. And you get to pick what color hand grips you want.

Came straight from china.
 

No pictures.:hmm: don't tease me like that. lol

Sorry! I had it on private. Can you see them now?

Ahhh!!! That's better. I though I was going crazy. :crazy: lol Did you get it installed yet?

No. Just got it yesterday. Probably do it Saturday.

Looking for more umph when accelerating on the trails. I need the front wheel to a least make an effort to raise up when I need to go over a rock, tree, ditch etc. I thought it might be the clutch slipping but runs too well climbing. It pulled me and my wife through some stuff I had no business going through. Lol. So I am starting with the carb. Bike is stock except for 12 tooth front.

I think that should help some. Will wait for the results.:)

I installed the Mikuni 30mm Carb on my Apollo 250. Bike runs fantastic, but I have not taken it out on the trails yet. Prior to replacing the carb, I installed a 52 tooth rear sprocket. With your 12 tooth front sprocket, you could use a 48 tooth rear sprocket. The rear sprocket made a huge improvement. My build is below, and has the specs for the rear sprocket.

http://chinariders.net/showthread.php?t=20620

Something I have been curious about with those carbs, since I have considered getting one on my Hawk. Does the accel pump have any timing adjustment to it? If so, make sure to check and adjust it before running it to avoid any potential tuning headaches. You will want the spray from the pump to just clear the throttle slide as it opens. If it hits the throttle slide, it can make for some odd behavior, and if it sprays too late you can end up with a lean - very rich - normal behavior that can make for a very entertaining experience.

It's a good idea to setup and test this with the carb off the bike. I like to use mineral spirits over actual gas, but that is just personal preference.

The key difference between the VM26 and this particular carb is the accel. pump. It doesn't really add more power, but instead helps eliminate the slight moment of lean condition that happens when you open the throttle more.

On a standard carb like our Mikuni clones, the air rushes in, but it takes a moment for the fuel to be drawn in. On a well tuned carb, we won't really notice it as any sort of dead spot, but it does cause a minor delayed feeling in the throttle response.

The Accel pump squirts a tiny bit of fuel in right when you open the throttle to help eliminate that lean spot, and it gives the engine an almost light switch feel to the throttle. Good for when you want to be able to have power right when you request it. The CRF230F 26mm Keihin carb has a rod actuated accel pump from the factory, Many dirt bikes tend to for this reason.

Whew! Just in time Megadan! I had everything off and ready to install my new carb. I will test it first. I changed the jets already and moved the needle up one notch. It does have adjustments on the the cam and the cable. Thanks!

Here is the difference between a standard carb and a an accelerator pump carb.

http://www.chinariders.net/picture.p...pictureid=1311

Cool, have you installed it yet? I'm anxious to hear your feed back.

The carburetor I ordered came with some kind of spring loaded choke. I assume there would be a lever mounted on the handle bar to use this. It came with the parts to change it over to a manual choke also. Here it is with the conversion done and the spring loaded parts removed.

Looks just like the original carb from this side.

http://www.chinariders.net/picture.p...pictureid=1309

That bracket and spring are actually to allow you to run a cable choke for a handlebar choke lever if you so desired to set one up.

From the "pumper" side you can see a big difference. This set-up requires a dual throttle cable to operate the regular slide inside the carb and the cam mechanism on the outside. The cam pushes down on a little pin that presses a diaphragm which squirts a small amount of raw gas into the venturi as you open the throttle. This gives you a more instant throttle response than a regular carb rather than waiting on the gas to get sucked up from the bowl.

http://www.chinariders.net/picture.p...pictureid=1311

I had a carb much like that on an old Honda XL250S, and it was a pleasure to ride. The throttle response was noticeably crisper than the 30mm Mikuni carb I'm used to, even when properly tuned. That bike started with one lazy kick.

So here it is installed. No big deal on getting put on. It comes with a new throttle cable and twist grip. You can see the cable is white. The only thing to watch out for is the gasket and insulator/spacer that goes between the carb and intake. It can be put on backwards. One way it fits perfect. The other way it blocks part of the intake. I changed out my gas tank to a plastic one while I had it apart. It actually took me longer to get the tank on than the carb and it was made for the bike. lolhttp://www.chinariders.net/picture.p...pictureid=1310http://www.chinariders.net/picture.p...pictureid=1308http://www.chinariders.net/picture.p...pictureid=1312

All I can say is WOW! WOW it starts easier. WOW it runs better. WOW it feels like it has 5 more hp. WOW WOW WOW!!!! :yay:

I almost can't describe the difference in this bike with that carb. I can choke it. Crank it. Choke off and go! Before, I had to let it warm up for 5 minutes before it would run without stumbling. Absolutely great when going slow then punching it. Takes off immediately. It almost feels like I put a NOS system on it. The overall feel of the bike has totally changed. It runs so much smoother. And I mean as in vibration smoother. I can't really figure how it made the engine vibration less. While testing, I wanted to really load the engine. I put my wife on the back and went down the pavement. We have some pretty steep hills around here. I wanted to close and open the throttle with it under full load to see how it ran. We went about 2 miles up hills, down hills, and on level ground. It pulled every time, every gear, without a stumble. When we got back she commented on how smooth it was. I said yeah I noticed it too. It is like I had put a counter balanced engine on it along with the carb. I have never seen anything like it. I have worked on engines my whole life and never seen such a transition in an engine. I couldn't hardly stand to go down the pavement before because of the vibrations. I thought it was a combo of knobby tires and uncounter balanced engine. Now its a pleasure. Just one of the greatest modifications anyone can do to an apollo 250.

Great to hear, I found the kit. How did you jet the carb, and what are your settings? What is your altitude?

Where did you get the plastic gas tank? Could you provide a link?

I installed the Mikuni in my bike, and it was a night and day differnence. I had very similar issues that you experieced with the stock carb. Really glad to hear it worked out. That's awesome!

I have read about the Mikuni. I might get one just to compare.

Only thing I did to the carb was put a 115 main in and raise the needle one notch. Set the cable so the pump worked just after the slide started up. 1 3/4 on mix screw. I live near Charlotte NC. Not sure of altitude but I am sure not too high. lol

http://store.orionmotors.nl//index.p...sort=2a&page=5

Link to gas tank and lots more. 12 tooth sproket, tank, gas cap, and passenger pegs.
Just select the RX250. It is the water cooled version in their country but most of the parts interchange. They were pretty fast with shipping. I think they are Dutch and for some reason the shipping didn't calculate right. I had to send more $$. But it was still very reasonable. They have everything to put original lights and controls if anyone is interested.

I had a slight problem getting the tank to sit right. I had to re-drill the mounting bracket hole down and over to get it lined up. Took me longer to find my drill and 1/4" bit than to do the mod. Looks great and all the original plastic lined up perfect.

Nice upgrade. :tup:
I'm still running the stock PZ30 on my Hawk. I am planning on upgrading the carb eventually. For the price I think I'm going to try one of these. How are the grips compared to the stock ones?

The grips seem good. I have not been on a 2 hour trail ride yet but just around the yard they feel good. Better than the stock ones for sure.

They just look more comfortable than the Hawk ones for sure.

I really liked the bike before. Had plenty of power. Power just didn't hit a low rpms like I needed. Now it is like you say "crisper". When I grab a hand full of throttle I had better hang on. It is like having a hot rodded version of the Apollo. It starts quicker and no warm up needed.

Its_not_a_honda:

Are you located in the US? I checked the Orion site, and everything is listed in Euro. If in the US, how long did it take to get the gas tank?

Douglass

Hahaha! You didn't read all my all of my post did you? :hehe: That's ok. I live near Charlotte NC. The center of all the NASCAR teams. Home of the Carolina Panthers. Close to the Lancaster Motor Speedway (the fastest 1/2 mile dirt track in the south). About as US as you can get. lol

Yeah the Orion site is in euros. I used paypal at check out and it converts to dollars. You can add all your stuff and google to get the dollar total if you want. I can't remember the time it took to get the parts. I think it was more than a week but not 2. I considered it fast compared to some of the china sites. lol

Don't forget to get the gas cap!!!!

And that is the result of no lean spots when rolling on throttle. Eventully I may switch over to one myself.

didn't you have a koso flat slide to put on...



.

Your 100% right :doh:. You had already answered the question when you told me you lived in North Carolina when I asked about the Altitude LOL.... I was going to fast bouncing around on the two sites. The site listed in Euros threw me off. Thank you for the links. I'm going to pick up a Carb for sure, and check out the Orion site.

When you adjusted the Needle clip, do you remeber what slot it ended up in? Do you know what style/brand of jets the new carb uses?

A couple of them. I have a 32mm Koso with a power jet and I also have a genuine Mikuni VM30 with a UFO on the slide.

I have quite a carb collection going lol.

[QUOTE=When you adjusted the Needle clip, do you remeber what slot it ended up in? Do you know what style/brand of jets the new carb uses?[/QUOT]

So we don't get mixed up in which direction:
http://www.chinariders.net/picture.p...pictureid=1313

I had originally ordered a jet kit from 6sigma. You tell them what you have and any modifications you have done. They send you a kit to optimize your carb. I never installed it in the original carb so I just used the main jet for this pumper carb. The other jet was made a little different so I didnt change it. Took a chance ***got in a hurry to try it***.

Its_not_a_honda : Perfect thank you for confirming. Last question, Did you get the pilot jet size by chance? I have a feeling I should be able to jet this carb very similar to the Mikuni. You are running the same size Main jet as a buddy of mine in South Carolina who is at about 800ft on the same bike as ours.

Megadan: I bought a Keihin Brand PZ30 pump carb. How close do you think the jetting will be on the Mikuni vs the Keihin as far as fuel supply go? I have a 30/120 in the Mikuni, should I just buy the equivalent sizes in the Keihin brand? I would plan on buying a few different sizes.

Using the VM26 jetting as a starting point isn't entirely a bad idea, but you will likely have to tweak the jetting a tiny bit to run better with the pumper.

In this case, the keihin pilot jet size will likely be around a 40 (38, 40, 42). The main jet, if we are comparing genuine jets, would be around a 138 - A mikuni 120 orifice size and a Keihin 138 are the closest equivalents to one another. Wether this holds true with the jets from other companies is a different question.

Awesome, thank you for confirming.

The pumper came with a 112. I put a 115 in it when I did the install. Keep in mind my bike is stock. Exhaust, air box, and spark plug. These jets have a "K" then the number on them. Here is what you get from 6sigma for the completely stock Apollo 250.
http://www.chinariders.net/picture.p...pictureid=1314
Like I said, I just used the 115 main jet from the kit that was for my original stock carb. The pumper carb had an adjustable needle already so didn't need the shims. The pilot jet was made different so I didn't change it. I could not tell what it was either. If there was a mark on it, I could not see it.

Right on, this gives me a great starting point. I'm going to set the carb up just like the Mikuni as a starting point, and buy a few extra sizes. Thank you for providing all the feed back and links. I ordered the carb this morning, ill probably see it with in two or three weeks.

Douglass

If it interests you to learn the slow jet size, you can use a hillbilly method that will get you in the ballpark. If you buy a numbered drill bit index that ranges from 61-80 (generally in the $4.00 range, including shipping from China), you can find the bit that matches your slow jet and then measure the bit with a vernier caliper. Don't trust the size marking on the index; you have to actually measure it to know for sure.
A Metric measurement will be equivalent to a Mikuni jet (eg. #38 = 0.38mm). Once you know that number, you can cross-reference to a Keihin chart.

The index will come with a pin vise, which allows you to chuck the bit and drill a jet. I've drilled several slow jets that way with good results. Here's one: https://www.ebay.com/itm/17pc-Fine-T...UAAOSwR2RaJ9~m

I thought about doing that. I used to race go karts and had to drill all my own jets back-in-the-day. There is an art to doing it correct. Thanks for that link! I am going to get that set. I have lost some of mine through the years.