RPS hawk 250 idle issues

[Harmlesssphinx]

From the start I have not been able to idle the bike without choke. I replaced the carburetor with the mikuni clone and I'm still running into the same issue. I'm not a mechanic so I'm hoping to find some tips and tricks to help me troubleshoot. Thank you in advance.

[Bruces]

What carb did you buy ?what jets does it have in it ?

[Skyd]

When you say you bought the mikuni clone, did you simply buy it and install it? Or did you tune it first? Proper Jetting and adjusting your idle mixture screw are for sure gonna help you out here. I'm not a carb guru, I know the basics but it's not my strength only because I haven't done alot of tuning but the basics aren't that hard.

For idle I believe your pilot jet and the mixture screw are your main points of interest.

[JerryHawk250]

Before you drive yourself nuts trying to tune the carb. Take the time and adjust the valves. They are know for being set with little to no gap from the factory. Read through the stick at the top of the dual sport section. It will have all the info you need for guidance with a new bike.

[Skyd]

Ahhh Good point Jerry - I always forget about that. Tight valves will make it hard to start too if you happen to be having that issue.

They should be checked and adjusted regardless of if you need to tune the carb or not so I'd go with what JerryHawk said first.

[Harmlesssphinx]

Thanks everyone, I'll check the valves, fingers crossed! It would make sense if an aftermarket carburetor provided the same issue.

[grumpyunk]

One other thing to check is open ports. Some have vacuum ports that could be disconnected "back there where you can't see...". If so, you could have excessive air being let into the intake and cause a too-lean mixture that would likely cause an unstable idle.
tom

[Harmlesssphinx]

So I adjusted my valves to .003 and .005 with no luck. So to be more descriptive. If I turn it off choke it sounds like it popping and it bogs down after half throttle.

[Megadan]

Originally Posted by Harmlesssphinx

So I adjusted my valves to .003 and .005 with no luck. So to be more descriptive. If I turn it off choke it sounds like it popping and it bogs down after half throttle.

So, let me start with... Are you sure you are turning OFF the choke? The VM26 clones have a choke that works backwards from the stock carb. Believe it or not, this is a more common mistake that you would think.

Also, you never did answer a very important question asked by another...

What jets are in it?

[Piglife]

Completely agree.
1) Adjust your valves
2) Confirm choke is off (down position on Mik clone VM 26)
3) Elevation has a lot to do with jetting, you can google a jetting calculator for specific jet sizes. Your pilot jet is responsible for idle - 1/4 open throttle
Inspect your spark plug to get an idea, you want a “golden brown” color, not black (to rich) and not to lean either. If your not sure it’s safer to be a little rich than lean.
*Im at ~6700’ and am running a 98 main and 42 pilot if that helps you at all. I’m also (as of yesterday) running a NIBBI PZ 30 (connected to box not AirPod) it’s a good carb, did a little more than 100 miles on it today with no problems but for the cost difference I can’t say that it’s a ton better than the Mik clone-took a while to dial it in to.

[Piglife]

Originally Posted by Harmlesssphinx

So I adjusted my valves to .003 and .005 with no luck. So to be more descriptive. If I turn it off choke it sounds like it popping and it bogs down after half throttle.

Mid throttle sounds like a needle adjustment (assuming it’s a carb issue)

...maybe? It’s definitely worth ruling out and simple enough to check.