First Timer w/ Apollo 250

[blanc12]

It is probably your jets. I have a hawk. Looks like the same engine. I too have the mikuni carb. I am currently running a 27.5 slow jet and a 115 main jet. Runs like a top.



as far as the valve adjustment. Pull the spark plug. bring it to top dead center. the line on the stator will be in the window on the left side. Both valves should be fully closed now. If they are not you need to turn the engine over again. Ok. Both valves are closed. Take your feeler gauge and try to place it between the top of the valve and the rocker arm. If it goes in and their is a slight drag you are done. If not, loosen the nut on the rocker arm and then move the screw down until their is a slight drag. Tighten the lock nut. Recheck the clearance. I believe the valve setting is .05mm or.002in. I set mine at .003in. loose is better that tight up to a point.

[culcune]

Originally Posted by 603Dirt

If changing the jets doesn't solve the idling/bogging down issues I suspect I should look into replacing the spark plug and if all else fails adjusting the valves. How hard is it to adjust the valves?

I've watched this video on Youtube
where he explains how to do it but doesn't exactly show how to do.

I am fairly certain you can watch other Chinese bike videos for adjusting the valves. i.e. Motocheez's video(s?) on the Hawk or the ones for the Bashan bikes. However, make sure you watch one that matches your engine whether it is OHC or OHV.

[Weldangrind]

Originally Posted by 603Dirt

Hey Weldangrind,

Sorry for the long delay. Busy summer so far but I'm looking to invest more time in this to get ready to ride for later this summer into the fall.

In NH I'm anywhere between sea level and 1500' above it. Would you recommend changing the stock Mikuni jets and does it make a difference whether I'm at 200' 500' or 1500' ? I plan on taking the bike through the state to different elevations and want to plan accordingly.

There were two hoses that connected to the air box before and I'm not sure where those should go now?

If you optimize jetting at sea level, it'll be fine to 2000 feet. If you continue to climb, it'll probably refuse to run around the
6000 foot mark. I like to use a #30 slow jet at sea level; it makes it a bit tough to start in hot weather, but it's easier when it cools off. A 115 main should do the trick for you.

Show us where those two hoses lead. I'm guessing that one goes to the crankcase vent and the other to the AIR valve, but I'd like to be certain.

The video you linked is for a pushrod motor, but that doesn't matter. Just follow the instructions blanc12 provided and let us know how it worked for you. I'll add that it's easier to turn the motor with a breaker bar and socket than it is to use a ratchet. Also, only turn the motor counter-clockwise, as viewed from the left side. When you line up the T mark in the viewing hole, you should be able to wiggle the rockers. If not, turn the engine one more complete rotation.