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sburk
10-30-2023, 08:18 PM
hello everyone new to the forum and to china bikes.
i just got a new xpro hawk 250 today. i put it all together and let it run and and cool a few times.
after that i ran the gas station and got some gas and when i got home the exhaust pipe right at the head was glowing red. i have not rejetted it yet
from what every one on you tube has said they run lean from the factory.
is this the problem? if so what size jet do you think i need? i am at 696 feet above sea level. i am keeping the stock carb for now but will mostlikly get a nibbi at some point.

XLsior
10-30-2023, 08:39 PM
If its a tamper proof carburator then prior to any modifications to jetting, try adding a small washer as a needle shim to 'richen' the mix...it might not be perfect but it will be the easiest thing to change to help with an overall lean burn while riding on the throttle.


as the needle position will have little to no effect on the pilot circuit.

JerryHawk250
10-30-2023, 08:40 PM
There is no exact jet size. You will need to get a set of jets and try until you get the correct size for you particular bike. Start off with a 110 main and work your way up until you fine what runs the best.

sburk
10-30-2023, 09:23 PM
If its a tamper proof carburetor then prior to any modifications to jetting, try adding a small washer as a needle shim to 'richen' the mix...it might not be perfect but it will be the easiest thing to change to help with an overall lean burn while riding on the throttle.


as the needle position will have little to no effect on the pilot circuit.

i am aware its tamper proof. i have watched a lot of motocheez videos. i am going to try and slot the screws and switch the main jets when they get here hopefully tomorrow.
am i right about it being to lean that is why the pipe got red?
thanks for your help

sburk
10-30-2023, 09:25 PM
There is no exact jet size. You will need to get a set of jets and try until you get the correct size for you particular bike. Start off with a 110 main and work your way up until you fine what runs the best.

from all the vids i have watched lately it seems around 110/115 seam to be what a lot of people are using
thanks for the reply

JerryHawk250
10-30-2023, 09:30 PM
from all the vids i have watched lately it seems around 110/115 seam to be what a lot of people are using
thanks for the reply
That's a good place to start on a stock setup.

Tomshell
10-30-2023, 11:37 PM
Sure sounds too lean. Pull the plug and look at its color. Should have some color. Reference a plug chart online and see what that says. Or better yet take a picture of the plug and post it...

Tomshell
10-30-2023, 11:55 PM
In fact, I can only remember a few times when I saw a bike exhaust glow red....I would be a bit concerned. Could be a bad exhaust valve too.

JerryHawk250
10-31-2023, 07:29 AM
I would suggest adjusting the valves first. Yew we know it's a new bike but most of these Chinese bikes come from the factory with the valves set with little to no gap. This will save you a lot of headaches when it comes to tuning the carb.

sburk
10-31-2023, 05:00 PM
UPDATE
i pulled my valve cover off and set the valves. first time i did it i set them to what a video said .005 exhausts and .004 on intake. i was top dead center according to the fly wheel and when i got done they the chatter was ridicules. i got on here and looked through the forums and found a post saying that they should be set to .04mm intake and .05mm for exhaust and that the piston hits tdc 2 times once on compression and once on combustion. (didnt think of that but makes sense now that i think about it ) anyway set them and they sound way better.

i got my jets in the mail i put a 115 mikuni jet in after breaking in to the carb with a dremal. she is running great thanks for the help guys its very friendly around here. im glad to be a member

i am going to start a new thread on here at some point and keep all my question and updates there to keep it easy