dooksy72

my bike pops and visibly backfires on deceleration, could this be rich in high revs and lean in low maybe? im still trying to learn

mine didnt have any circlip. as indicated on the instructions that came with the kit it said if your carb doesnt have a circlip then add 2 washers to raise the needle manually, so ill just have to remove the washers or just trial and error etc. worst come to worst ill have to replace the needle/carb. thanks for your input its greatly appreciated and ill get back and let you know how i get on and if i fix it and if so how

I didnt drill the hole as i dont have a drill in my workshop currently. and thank you i will give these things a try. Im sure everything was seated again properly, i checked the slide before i reinstalled it and it appeared normal. Hold on , don't drill any holes ! Unless the Sigma kit also says that you need to . If it does then there should be a drill BIT in the kit . I looked at the DYNOJET instructions so the Sigma kit could be different. To be quite clear, if the Sigma kit says to drill a hole to make an existing hole larger and you didn't do so that could explain the slow drop in revs. If you do have to drill use a HAND drill not an electric drill and do it carefully . Good luck. it said to drill the hole but it was usually only for race applications and it could change behaviour drastically. so i didnt bother atleast not yet, so what do you think my best bet for the slow rev drop is along with the other stuff you mentioned?

I didnt drill the hole as i dont have a drill in my workshop currently. and thank you i will give these things a try. Im sure everything was seated again properly, i checked the slide before i reinstalled it and it appeared normal.

put the stage 2 jet kit in, it runs without chugging now at all RPM ranges from my test ride this evening. However when i rev the bike it takes almost double the time for the revs to return to idle. must be mixture again but i cant do anything as the screw is totaled. it idles consistently but sometimes it sounds a little choppy other than that its fine and a usable bike. Don't be jumping to any conclusions just yet have a good read of the Dynajet troubleshooting guide . I'll have a look to see what sort of carb it is before offering any further suggestions. Its a Sigma jet kit, ill have to have an in depth read but your input would be greatly appreciated.

I'd rather not as I've spent a substantial amount of money on these parts and the aim is to improve the performance as much as possible as I'm going to have the bike for at least another year and a half; also learn along the way. I can't see why you didn't go ahead and install the dynajet kit anyway, most of what you pay for is in the shape of the needle and the appropriate jet might cure rich running. As I have said , the pilot air screw might not play as big a part as you believe. put the stage 2 jet kit in, it runs without chugging now at all RPM ranges from my test ride this evening. However when i rev the bike it takes almost double the time for the revs to return to idle. must be mixture again but i cant do anything as the screw is totaled. it idles consistently but sometimes it sounds a little choppy other than that its fine and a usable bike.

I will go ahead and fit the new jet kit and see how it runs and get back to this post.

I'd rather not as I've spent a substantial amount of money on these parts and the aim is to improve the performance as much as possible as I'm going to have the bike for at least another year and a half; also learn along the way.

Recently bought K+N air filter and Black Widow exhaust along with a stage 2 jet kit to improve the performance of my bike. However while stripping the carburetor I attempted to count the turns of the fuel mixture screw as a starting point before I installed the stage 2 kit and found the screw was rock solid. Due to this in my efforts to try and free the adjustment screw I broke one side of the "flat head" screw rendering it irremovable unless I were to drill it out. The jet kit doesn't come with an additional mixture adjustment screw so I was forced to put the carburetor back together as it was when I removed it with the stock jets. The bike runs acceptably but just rich I've gathered, and between 5 and 7k RPM sometimes the odd "chug" if I linger at those RPM at a consistant speed. I can accelerate hard completely fine and it idles fine from cold. I'm just wondering now what the best move is; to ether go ahead and buy another carburetor for my bike which is hard to find from my efforts, to find another carburetor that would fit my bike and the stage 2 jet kit I bought originally for the stock carburetor or to drill out the existing mixture screw to replace with a new one but risk damaging the carburetor in the process. My plan was originally to install the exhaust and air filter, clean and install the stage 2 jet kit into the stock carburetor and then adjust the fuel mixture to compensate for increased airflow, additionally I was planning on swapping out the stock drive sprocket of 15 teeth for one of 14 teeth to improve acceleration. Any advise and constructive criticism is greatly appreciated. Many Thanks Michael