1985 honda 200x Question

[curtis slawson]

im having some carb issues. fresh rebuild .20 over 10-25-1 wiseco piston.


so when i go to start it on full choke start's first kick run's good. When i shut off the choke it kinda bogs out and die's but if i drive it when the choke is on and then shut the choke off it run's fine no bog or nothing. Also im hearing a pop sometime's coming from the airbox i think.

what iv done already i had a 108 main befor in it ran wost then when i put in the new 110 jet from the carb kit run alot better but still act's up when i first start it up.

so do i need to keep jeting it up


when i had 108 main jet in i took the airlid off and it ran a little bit better

but the 110 main jet working better so far . so what u think i need to thanks:naughty:

[Motorious]

Curtis,

According to the factory service manual, stock main jet for an '85 is a 108. Unless you've got a performance exhaust and air filter, you shouldn't have to go bigger than that on the main; matter of fact, if you're riding around 5500-6000 ft or higher elevations you need to drop down on the main jet to a 102.

Based on your somewhat contradictory descriptions about whether or not it's running lean or rich (and also this part): "im hearing a pop sometime's coming from the airbox i think..." (backfiring a bit perhaps?), I've got a hunch that your timing might be a little off; I'd re-check it starting from the beginning with the "T" mark on the flywheel lined up with the index mark on the flywheel cover, and check that the "o" timing mark on the cam sprocket is aligned with the index mark on the cylinder head, continuing on with the the index mark on the pulse generator being aligned with the index mark on the rotor whilst the "F" mark on the flywheel is aligned with it's index mark. You've got a manual right? Should be able to find a free manual download for a 200X on the site somewhere if you don't have one. The "T" and "F" marks on the flywheel are extremely hard to see (even with a flashlight), and are on the beveled upper outer edge. When I timed my 200X I had to pull the flywheel cover off briefly in order to locate them as the crappy photo in the service manual was no help.

Other things to check: valve clearance, float level, pilot screw adjustment, slow jet (is it the right size?), carb is dirty or needs to be rebuilt, air leaks around the intake and/or airbox, dirty airfliter, clogged petcock, fouled plug (what color is it?).

[350xx]

Sounds like jetting to me. If your timing is right and all the engine components are right, then its jetting.

Sounds like its too lean.
If it backfires through the airbox its too lean.
Check your plug and post a pic of the plug too.
Other riders with built 200x's will help with proper jetting.
But its really test and play, test and play.

[curtis slawson]

Sounds like jetting to me. If your timing is right and all the engine components are right, then its jetting.

Sounds like its too lean.
If it backfires through the airbox its too lean.
Check your plug and post a pic of the plug too.
Other riders with built 200x's will help with proper jetting.
But its really test and play, test and play. yea i dont think it's timming has no problem starting or running its just when u first start it up it run's bad till it warms up here's a picture of the plug

http://i42.tinypic.com/34zd6iu.jpg
http://i40.tinypic.com/rqyv05.jpg

[pcs]

well you should let the engine warm up before you start riding anyways. not good to push a cold motor hard that has not had a chance to properly cycle oil through out.

[Motorious]

Speaking from experience I had the ignition timing a little off on my 200X after I had replaced a burnt valve, lapped the valves, honed the cylinder, replaced the valve seals, and de-carbonized the head. Initially it started and ran OK, but it backfired on deceleration, was down on power, couldn't get it to idle properly (would die unless idle was set high), and started fouling plugs. I assumed it was a jetting issue too seeing as how the PO had put a 122 main on it (stock for an '83 is 110); but I also have a Cobra exhaust and a K & N filter (stock airbox though), and to complicate things even more, I ride at between 5500-7500 ft elevation.

Interestingly, before I did the top end work, the jetting seemed to be spot on with the 122 main based on the perfect chocolate color of the plug. So I wasted a lot of time with carb adjustment and changing the jets and still couldn't get it to run right. Once I decided to re-check the timing (which on a 200X isn't a big deal), I realized it was off a bit, re-adjusted it, and-finally!- it no longer backfires, idles the way it should, has a lot more power, and is no longer fouling the plug. I still need to fine tune the jetting (and maybe move the jet needle) a bit since I'm at high elevation and have an aftermarket exhaust and air filter (still think I might be a tad rich with a 112 main and 40 slow jet), but it's made a huge difference.

Since you've just got done rebuilding the top end, I still think it may be worth the effort to re-check the timing because as I wrote before, a 108 main is what is supposed to be on a stock '85 200X. A higher compression piston alone will not change that. It's obvious now by the color of the plug that it's running lean, but you still haven't told us whether or not your running a stock air filter/exhaust/carburetor, and what your elevation is. A little more info would be helpful to us to help you. Just because a motor is running lean doesn't necessarily mean it's jetting related: timing could be off, you could have an air leak, float levels could be off, carb could be dirty.

[WilliamJ]

Curtis,
Check the timing as Motorious advised. Both valve and ignition.

So it starts okay - doesn't mean the timing is right. I build race car engines for a hobby and you can get them to start with the timing way out. 40 degrees and more. Run like crap though. Spitting and popping.

Also the cam timing. I made a couple of mistakes with that over the years and unless the valves hit the piston the engine will seem to run fine in the workshop. On the track or on the dyno - no power at all!

And remember - there is no point in adjusting your carb unless the timings are spot on. When you do fix the timing you get to adjust the carb all over again!

Good luck.
Bill