Hey smb05.

I noticed that they do quite a bit of modding on buggynews.com to these same engines and they seem to use 127.5-130 for the main jet after changing to a uni filter and opening up the stock exhaust. The 127 can be acheived by drilling the existing jet with a #56 drill bit from Irwin tools.

My carb seems to be very similar only throttle is on the opposite side. I need to learn more about it first, but my main jet is 105. I have it apart right now because I had a lot of black flakes in my gas tank from the factory and they made their way into the carb. Since so many have trouble with the electric choke (fuel enrichment circuit) on these, I think I will jbweld the choke ports up, leaving one with a fuel line stub to put a primer bulb on for choke.

Let you know how it turns out. Thanks for the information.

 

Oh the choke thing. Does yours have that electric choke? Apparently, it lets extra fuel in by default, then when the engine is warm, it activates and closes the port to reduce the amount of fuel to normal. So if something goes wrong with it, your quad will run well when cold and sputter and die at idle when warm... which mine does.

 

rocketmagnet,

Thanks for the info. Started to look at the site. Lots of good information there. Those guys are putting different carbs on their buggy's, that's cool. I was thinking of doing the same to my 150.

The 127.5 to 130 seems a little rich but I still need to go the site to see what they did. I was thinking of more in the lines of a 118 to 122 main, and a 40 to 45 pilot. Still need to find needle. I may pick up the 125 and 130 main anyways, never know. I will drill the main as a last resort.

I installed the power up kits in my CRF 150's. Basically the same mod as this. The main jet was a 98 and it went to 108 in their kit. Changed the needle and bushing and did not change the pilot. This was Honda's kit they sold. So I was thinking I would start by jumping up the same number of jets as they did.

Look into the electric choke conversion kit. Which 150 do you have? If you look at my pics, the Pipe Reducer Pic shows the manual choke cable. Price compare between a conversion kit or a new carb with manual cable. I can get the carb for $35.00 and the cable is $20.00. My throttle cable is on the right side of the carb is yours on the left? Also did your 150 come with a fuel filter installed. Mine did, leaked from day one. Replaced it with another one and it's picking up the black flakes your carb has in it.

There is a shop in town that sells the buggy's and quads. I will find out from them what they have done, will have more information on these jets tomorrow. Hope to start rejetting by Wednesday or Thursday.

 

Hey smb05. Thanks, you give me a lot to think about.

I don't really know much about my 150cc, but it is a GY6 Honda clone. I was just going to change the main jet, put in the uni (on order), open up my stock exhaust, and convert my carb to manual choke with a primer (as is shown on this page: http://www.rc-trucks.org/gy6-engine-performance.htm). I thought you should change the needle too, but the guys on buggynews haven't as far as I can tell and theirs work well. I drilled my jet yesterday so if I need to go back, I'll have to by one (they have them on bladepowersports.com). Going with a new carb might be better. I didn't know you could get one for these so cheap. I got one for my son's 110cc a while back on ebay for $60 or so and I thought that was a great deal. Where can you get one for $30? and what size is it. Mine is a 24mm CV carb like in the web site above. It has a diaphram that raises and lowers the needle which has its advantages and disadvantages and an electric plunger that blocks the fuel enrichment port when it warms up, at least in theory. I took my tank off and washed it out and got about a thousand black flakes out of it. I'll use a good fuel filter this time, not the factory cheap one and hopefully be ok. I'll let you know how everything turns out and I appreciate you doing the same. Thanks.

 

rocketmagnet,

Don't worry if you wreck your main jet, I just ordered a bunch of them. I will send one or two your way if you run into any trouble. As long as your carb is the PD24J. I'm not going to change out the needle. I agree with you, those guys did not change them out. Not only that, I could not locate a replacement. Not worth the time. I will just do the carb upgrade if I have to. I will P.M. you with the place where you can get the carb and cable.

 

I WAS WONDERING WHAT TYPE OF SILENCER THAT IS YOU HAVE ON YOUR DAUGHTERS BLUE ATV...?...Thanks My daughter has a Hi-Bird cHINESE aTV 200ST AND WE ARE HAVING FILTER PROBLEMS

 

XMUDCAT22,

The silencer is a Big Gun Race Pipe. The pipe was used on one of my CRF150's. The pipe had to be modified to fit the BMS.

If you are still using the stock air filter I would strongly suggest that you replace it with a UNI or a K&N. If you do replace the filter, make sure to check your spark plug color to make sure the quad is not running lean. Rejet as necessary.

You really don't need to upgrade your pipe. I did mine mainly because the pipe had a USFS approved spark arrestor in it. Here is a nice replacement pipe to think about if you do decide to replace yours. Pipe The cost on the pipe is not that bad either.

Good Luck.

SB.

 

I just checked the Spark Plug it was black...I just finished test riding it and it still seems to not have that much power like it used to and its only 4 months old...I did take the exhasut off back when i purchased it and cleared out the header it had some restrictions,But that shouldnt have done any damage,from what I understand that should have helped...I just dont know what else to do to get more power out of it,sometimes when we are out trail riding she can barely make it up steep hills and it wont even pull a wheelie and in your video you seem to be ripping it up on yours,should I try and rejet and if so what size should i start with...Any help would be greatly appreciated...Thanks

 

XMUDCAT22,

A black plug indicates a rich condition. The first place to look would be the air filter, make sure it is clean. The next place to look would be the carb. I do not know what carb you have but make sure the choke is not on after warm up. I have done this before, I left the choke on in the middle position, the bike would lose power and sometimes stall. If you have a CV carb you may have a leaking fuel enrichment condition. This will occur if the heating element does not close once the circuit warms up. Since you removed the insides to your pipe you should be ok there. I would also clean your carb and you may want to adjust the valves.

SB.