First ride on Apollo 250 Deluxe
 

Well that didn't go so good, it ran really good for about 2 minutes then it wanted to die thankfully I stayed close to home. I got it restarted and had to really work the throttle to get back. I parked it in the garage to let it cool down some, about 15 minutes then started it to see how it would idle. Just like my short ride it idled perfect, for about 90 seconds then died. Started it again and like my ride I had to work the throttle to keep it running but this time I noticed it missing really bad and making kind of a backfiring sound so I shut it down.
I'm open to any and all advice, tips or tricks. I think the first thing I'd like to do is replace the carb with the Mikuni from what I've read it sounds like a good choice.
That is in advance, Dean

Choke on or off ?

How about the fuel pet cock?

I would get the bike running acceptably as stock before I start throwing parts at it. I had to adjust my idle screw a bit to get it to idle. Remember, these are "old school" and you're going to have to sit with it and massage the throttle for a while to warm them up before you go for a ride.


I'd also pop some octane boost in the tank.

The choke and gas were in they're correct positions. What's strange is it idles fine until it warms up. I did put the NGK plug in it but I'm not sure of what the gap should be.

Another question, how in heck do you get to the idle screw? That is it on the right side right behind the frame?

Yes that's it. Just get a long flat head and angle it. I had to raise my idle and adjust my valves in order to get my apollo to stay running and run correctly. The valves were shut 100% when I took it out the box

Interesting about your valves. Do you think that's possible with mine? I just got it yesterday and I probably started it a half a dozen times and it ran and idled perfect, until I rode it now I can't even keep it running. I put some octane boost in it maybe that will help. Can you suggest what the plug should be gapped at? Thanks

The stock spark plug worked fine and it is gapped to spec, so im not sure if that would be an issue BUT This is the spark plug I bought and I love it, a few guys with apollos have had great luck with it. There are many spark plugs that will work BUT if you want my opinion this is the one I have. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 That right there is an NGK Iridium Plug that was pregapped and good to go. I bought a new spark plug cap too because i didnt like that old looking metal one haha Also about the valves, that may very well be your issue. When the valves are clamped totally tight like these apollos come, the bike does not want to idle very long or it acts funny when its warm. Adjust your valves to spec then go from there. Let me know if you have any more questions about the apollo. I dont know everything BUT id like to help where I can. Other guys on here are very knowledgeable.

Agree on the valve check. Mine were tight as a drum, no clearance at all on both intake and exhaust. I adjusted them before I even fired the bike up. I also put an NGK Iridium plug in the bike. Yeah, the stock carb is funky and jetted super lean, but it will idle now.

With today being another beautiful one here in the Pacific northwest I thought I'd try starting the Apollo after ending yesterday with it not wanting to start at all. I changed the plug back to the one it came with in it from the NGK they included with the bike. And what do you know, it started. I set the idle up a bit then let it run to see if it was going to do what it did after it warmed up yesterday and it did, it died. I could sure us some help trouble shooting this thing if anyone gets the time.
Thanks again, Dean

Buy one of these...
 

Tbolt USA has these knob type adjustors: https://tboltusa.com/store/tusk-fuel...k-p-10604.html

They sell a fancier adjustor for $35 or so that lets you adjust more easily. But the small knob style works fine, you just have to turn the knob with a screw driver end.

https://tboltusa.com/store/flex-jet-p-1063.html

Also can get the knob type on Amazon for $8...free shipping.

https://www.amazon.com/your-orders/p...ntId=DkVqqkG2d

This is for a Mikuni VM26-flange mount (like on most 250 China bikes).

Turn the Pilot Jet Screw "in" (CW) till it just stops. Turn 1-1/4 turn "out" on the screw, then turn out (or in) 1/4 turn increments. Have someone with you to keep the bike running while you turn the jet out (or in). Turning "out" (CCW) increases your fuel into the Pilot Jet since this is on the engine side of the carb (if the Pilot screw is on the intake side, as with other carbs such as the VM26-606, then turning out increases air). Do this until you get a good idle.

If you get past 2 turns out, then you should consider a larger Pilot Jet. If you have to turn "in" (CW) to make more lean (under 1 turn) then you need a smaller Pilot Jet. Order a couple jets (either larger or smaller depending on what you find)..I had to go from a 20 stock to a 30 to get mine to idle at 1-1/4 turns, 1500 rpm.

Once you get idle, then run at mid-throttle for a few miles (5-10) without stopping (much). Check your plug. Decide if rich (black) or lean (white). If tan, then OK. If black, then move the needle clip up one notch to lean out. If white, then move needle clip down one notch to richen. Do the spark plug check again. Look for Tan.

Find somewhere you can run full out for 10 miles. Pull over, remove spark plug. (I didn't shut the engine off at speed and coast to a stop like some folks say...I just needed to be close enough and I don't think going to idle for 30 seconds will change the plug much) Black/Tan/white? Go up or down one Main depending on color. Because I am at a Mile High, I ended up with the 100 Main that was stock (would likely be lean at sea level).

This process worked for me on my RXB150, that came with the "real" Mikuni. Tan plug all the time.

Jetsrus.com: Mains: Mikuni N100.604 (Jetsrus # M21), Pilot: Mikuni VM28/486 (Jetsrus # M24). I get my jets from them in 2 days. They are about $5 each for the aftermarket type and $7 for the genuine Mikuni.

Followed the same procedure when I put a VM26-606 on the TT250. I am down to where I am going to try one Main larger, as I got tan, but still a bit too white I think. I thought with this carb I would avoid the problem of the Pilot Jet Screw location (as with the PWK28 I was replacing it was accessible), but it ends up being the frame. Luckily, with a spigot mount carb it isn't a big deal (time wise) to remove the carb and tweak.

Did you do valves ? I know I keep mentioning but on my old bike, I didn't do valves and had the exact same issues. Maybe its not that but you should troubleshoot down a list so that you can cross things off one by one. Next you can make sure that your air box isn't blocked up...but I'd do that after I first do the valves. Its kind of a pain to get to on the apollo but it has to be done. Have to take gas tank off:/ also your air/fuel mixture can be lean..but again its all going down a list of trouble shooting!

Go to CSC and look over the Valve adjustment for the TT250
 

I agree on checking the valves. It isn't hard to do. Here is the CSC tutorial:

https://www.cscmotorcycles.com/check...lve-adjustment

I don't think it is any different for any CG engine bike. They recommend "looser" gaps than most on this site do, at .07mm for both. I only had a .06mm and .08mm, so I set at .06 and made sure a .08 didn't fit. I set, rotated 2 times, checked (had to reset exhaust), rotated 2 times, checked (had to reset intake), rotated 2 times...then it was OK.

Unlike the tutorial, I didn't take off my seat or gas tank. I only removed the right side plastic. My tank plastics are already off, so someone who has them might have to remove the right side only. For the TT250, the valve cover comes off easily to the right side.

Trouble shooting is definitely key and you've given me a starting point however, I know absolutely nothing about adjusting valves. Looks like I have some YouTube homework ;)
I will be calling Orion tomorrow to give them a piece of my mind. I was also wondering about air/fuel mixture and elevation of which I'm only about 250 ft.
Thanks again