atc 200 wont start, need help!!!

[hheywire]

Ok so here's the deal. I just reassembled the motor after taking it apart and it wont start. It has spark color of spark blue. It has compression, can really feel it
due to no compression release. It's getting fuel, I left the carb tuned the way it was when it was running before the rebuild. Spark plug gets wet when I choke it. I tried push starting it with an atv got the motor turning some high rpms and still nothing. Didn't even pop. I pushed it like that for about a quarter mile full choke,
half choke, no choke. Nothing happened. Brought it back home again checked the plug still getting spark and fuel. Tried pull starting it for gits and shiggles and it
popped but didn't turn over. Kept doing that but all I would get is pops. Then my pull start seized and that was the last straw I was done for the day. I'm going to get back to tomorrow. Any suggestions on what is going on with my trike? I'm just flabbergasted! It really is a mystery.

[NeverLift]

Sounds to me like the cam timing my be off. When you had it apart did you inspect the cam chain, tensioner and adjust the valve clearance?

[hheywire]

Oh yea I forgot to mention that. Yes the timing chain is on its mark and valve lash is set properly.

[barnett468]

Hello hheywire


CAM TIMING - I would recheck the cam timing, put the T mark in the window [not the F] with the piston at tdc.

GAS LEVEL - Check the actual gas level by putting a 10” clear tube on the float bowl drain fitting hold it next to the carb with the open end even with the carb top. Open the drain screw with the gas tank valve ON. The gas should be from even to the bottom of the upper carb body where it meets the bowl to 3/16” below it. If it’s above the carb body it is flooding your engine and the float needs readjustment.

START TECHNIQUE – Try starting with no choke and 0-1/8 throttle. If it doesn’t start after a few pulls check plug, if it is wet it is likely flooded. Check gas level and pilot jet size.

JET SIZES – I know it ran fine before but it is rebuilt now so it would help to know what the jet sizes are?

VALVES – Recheck, they can have a nasty habit of seemingly changing clearance for no obvious reason.

FLYWHEEL KEY – Is it possible you forgot it and the flywheel is in the wrong position?

CARB FLOAT - Might have a stuck float. If gas level is even with bottom of carb bore check it.

CARB NEEDLE - Might have debris in it holding it open flooding engine or simply dried up and leaks. Gas level test will determine if it has a BIG leak only. Turn gas off when not in use.

[barnett468]

If plug is black replace it don't clean and reuse it.

[my1423]

One other thing to add.

The advance unit for the trigger on the end of the cam.
It separates into 2 pieces.
The magnet and the advance weights with mount.
It can go back together 180 off and look like factory.
If it is off it will do nothing but an occasional backfire.

Pull the valve coves and the pulse cover.
Put the motor on f and see if the magnet side of the rotor faces the pulse coil. Has black line on face.
Make sure both valves are up at the time.
Move the crank 90 degrees both directions of f and see if any valves move.
If they do you are off.
Just pull the advancer apart and reassemble at 180.
Test it.

[tommerp]

I could add a couple simple things.. and I'm sure you already tried ....

Check your gas. If it's old... get some fresh and try again.
Check the intake between the carb and cylinder and make sure you are not sucking in air . the smallest crack will mess you up.


My 2cts

[hheywire]

Thanks for the advice yall, I'll try some of these tips and I'll let ya know how it comes along.

[kb0nly]

Sounds like the cam is off 180... Don't feel bad, plenty of guys have done that before!! LOL

Lots of good advice here, i will just add its definitely timing related.

[hheywire]

well I know the cam is timed right but the magnet for the pick up coil might not be. I think I have it 180 off.

[hheywire]

ok figured it out. The spinning magnet for my pick up coil was 180 off. Now it runs great. But something didn't feel right when i went to top it out. I was still accelerating in last
gear still had some more rpms to go and suddenly started loosing power so in case anything was about to blow I let off the throttle and nursed it back home. When I got back I
tried some hard accelerating again to see if it would still do it. It's fine again. Engine is working properly again. I might have to test it in last gear again to see if it happens again. Any one got any ideas what it might be just in case something catastrophic is about to happen?

[my1423]

Sounds like a gas flow problem.
Check the flow from the tank.
Rust plugs them up.





Just to be sure pull a valve cover and start it up. Make sure oil is getting up there in a continuous flow.

[barnett468]

Hello hheywire



it runs great. But something didn't feel right when i went to top it out. I was still accelerating in last gear still had some more rpms to go and suddenly started loosing power so in case anything was about to blow I let off the throttle and nursed it back home. When I got back I tried some hard accelerating again to see if it would still do it. It's fine again. Engine is working properly again. I might have to test it in last gear again to see if it happens again. Any one got any ideas what it might be just in case something catastrophic is about to happen?


PISTON SEIZE - When a cylinder is bored too tight and a bike is instantly ridden at WOT like you said yours was instead of being properly broken in which takes around 5 hours for a properly clearanced piston and up to 40 hours or more with one that is too tight, they occasionally minor heat seize exhibiting exactly the symptoms yours is. The only way to determine if this happened is to remove the top end and re inspect it. A minor seize condition can also possibly be partially contributed to the use of engine oil with insufficient amounts of zddp in it wehen used in a new tight cylinder.

What is the exact brand type and viscosity oil did you use?

REAR BRAKE STICKING - Make sure it has plenty of freeplay and that pedal moves and returns freely. A slightly dragging brake can expand when hot thereby putting drag on the wheels and subsequently slowing the bike. They free up when they cool allowing free movement of the wheels again.

CDI AND REGULATOR – A CDI that is failing CAN do the exact same thing. if it does it again try another CDI if you have one otherwise toss the CDI in the fridge for 20 minutes, reinstall then try again. If it still has a problem immediately then do to the same with the regulator although the regulator should have had enough time to cool off by then.

GAS CAP VENT – It occasionally happens that the cap vents quit venting and occasionally cause this exact or similar problem. If the problem reoccurs jut immediately loosen the cap and see if it fixes the problem. You can also probably try to blow through the vent in the open condition to see if it is venting.




while i had the engine on the table i took the courtesy of taking the whole thing apart to take care of the oil burning problem. I replaced the piston with a used one from an extra honda fat cat bottom end i had

Did you install new rings and hone the cylinder?




i checked the jug for scoring and it was minute.



PISTON/RING REPLACEMENT – You must measure the cylinder for taper and “out of round”. They can look fine but be out of spec. It should be less than .015 taper and out of round or rings will not properly seal and it will have low compression and burn oil. The cylinder should be honed and new rings installed or the will not seal properly and it will have low compression and burn oil.





i think the previous owner bored it out and put a stock size piston in it. IDIOT!!! the fat cat piston barely fits snugger than the old one though so it is a bit bigger but not by much. the previous owner must have bored it way large for the fat cat piston to still be a little loose. the old piston in there was way too loose! its no wonder it burned some oil.

What was the clearance?




i'm hoping i fixed the problem though.

You can’t fix low compression or a smoking problem caused by worn piston, rings, cylinder that way, it must be bored out with new parts installed.


ENGINE SMOKE – I think you said it smoked and klunked and the piston was loose after you "repaired" it in the post you cancelled.