davefrombc

Does it start and run if you use a manual starter ? If not , it is likely a bad neutral switch or relay

Try adjusting the idle air screw. Also may be valves set a little too tight or if the timing chain is loose it may have skipped a tooth. I'd try the idle air adjustment first , then check for vacuum leaks. If that doesn't do it, pull the carb again and make sure all passages are clear and jets checked for tiny missed holes . Blow the passages out with "Canned air" for cleaning computers and electronics if you don't have access to a compressor. If the problem remains then you'll have to dig deeper and check valves and timing. Usually running fine at idle and crap revved up or the reverse indicates a fuel rich or lean burn problem.

Links to download the service manual in 2 parts were posted earlier in the forum . The second part of the manual unfortunately is too large to download to our service manual section so I'll repost the links here. For the complete manual download both parts. \ https://www.hightail.com/download/OGhkUXVqQ0M4aU94djlVag https://www.hightail.com/download/OGhkUXVwTlFqV0FUWThUQw

View File 2007-2014 Honda Rancher TRX420 Service Manual 2007-2014 Honda Rancher TRX420 Service Manual Submitter davefrombc Submitted 10/16/2017 Category Honda ATV

The TRX 420 Service manual is now in the downloads section.

It is starving for fuel when you open the throttle . . Pull the carb and clean it again. Check all the jets for blockages and blow out the passages. Make sure the float level is correct so the float bowl fills to the correct level. When cleaning the jets , make sure to look for some very small holes in the main jet tube that might have been missed in the last cleaning .. Running good all day and then going to crap tells me the carb most likely picked up some small dirt that was missed in the first cleaning and became mobile to pug a jet . It often happens in machines that have sat for a long time and have sediment missed in the bottom of the float bowl, or maybe got by the screen on the fuel valve .

I can't offer any advice on it , but there's a service manual available in the downloads section . Go to browse/downloads/ ATV service manuals ( and more) and then the Yamaha section.

Can Am Error codes View File Complete list of Can Am error codes. Submitter davefrombc Submitted 10/01/2017 Category Can-Am BRP ATV  

I found a complete list of Can Am error codes on another forum and saved it to our download section. Here's the instructions for pulling the codes. 1. Turn Ignition to Lights On position 2. Set speedometer to Engine Hours 3. Press and Hold selector button while switching the Hi-Lo beam 3 times in a row (quickly) 4. Diagnostics mode is activated now 5. Use selector button to go through codes 6. END will come up when all codes are displayed 7. To end mode hold the selector button for more than 2 seconds Here is the direct link to the error codes in the downloads section.

Pull the carb and clean it . It is quite possible when he rolled it some dirt that was in the float bowl was shaken loose and is now plugging a jet. Bogging, quitting when "nailing it" and backfires are symptoms of too lean or no fuel flow on open throttle.

My best guess would be to go with the stock jet. In the good ole days of carburetted cars those symptoms would point to a faulty acceleration pump. Sudden opening of the throttle causes a drop in vacuum and with it a momentary starving of fuel . That's where the accelerator pump gives it a shot to make up for that momentary starvation .. It could be with the larger than normal main jet and air screw opened up ( most of them work best around 1 1/2 to 2 turns out from seated ) you are getting that vacuum drop and fuel starvation when you suddenly open it up. By opening the throttle slowly you don't lose the vacuum and fuel delivery.

Here is a direct link to the Warrior service manual in the forums Download section .. The wiring is the same throughout the Warrior model years.

The two metal tabs with the holes are for mounting the coil . The only electrical connection is to the thin flat tab your black probe is touching .. The trigger from the CDI connects there. the spark coil earth side connection is through the mounting tabs .

Quite possibly some water laying in the bottom of the float bowl again.. Some carbs have a bowl drain so you don't need to remove the whole carb to drain it out. Very possible there was a little water left after the carb and tank cleaning .... or a little bit of rust/ crap came loose from somewhere and is blocking a jet.. I'd pull the carb and give it another blowing out and check jests and passages . No need for a new kit . .... just pull, clean and it'll likely be fine . If you don't have air available to blow out the carb passages, the "canned air" used for computer cleaning works well.

I can't give you any specific instructions on how to access it, but can give you a tip on breaking loose and removing the nut holding in on the shaft. Most try to do it with just putting the quad in gear to try to keep the shaft from turning , but the nut is usually so tight it turns anyway .. Put the chain on the sprocket and then clamp the chain so it holds the sprocket and keeps it from moving while you undo the nut .. There are videos on Youtube showing others changing the drive chain so you can see how it is done and adjusted. I didn't see one on changing the Polaris sprocket though . Search Youtube for changing the front drive sprocket on your machine . You may not get a full video of your machine but you will get videos of others being done . . I didn't see any mention using the chain to keep the shaft from turning when you go to remove the nut but it is a trick I've used many times removing sprockets on machines a lot bigger than a quad.. LOL... Wrap that chain around the sprocket and clamp it so the chain can't move and the nut will come off without the shaft moving.

It is likely labeled pilot air jet on your carb . Most carbs have only two adjustments . .The idle speed screw which is the throttle stop setting and the idle air ( pilot) mixture .

Nobody in your quadding acquaintances have a small wire feed welder? They're pretty common out here among the ATV and 4x4 clubs. A light duty flux core wire feed is not expensive and will do all the welding you want to do on ATVs and most things that need welding repairs around a home and yard. They're not hard to learn to use and it's surprising how many projects you will come up with if you have one. Sorry I can't help out from the other side of the continent. My wire feed gets a fairly regular workout.

Rock it back and forth a bit as you try to shift it into neutral.

Likely all it needs is the idle air screw adjusted .. Turn it in until it just seats, the back off 1 1/2 to 2 turns . Adjust in or out 1/4 turn at a time to find where it idles. Adjust it until it starts to "lope" and then enrich it about 1/8 turn. \

Is it something a little cleanup and re-weld can't fix ?

I can't help directly , but there is a service manual in the forum's Download section . . Click Browse / Downloads then ATV Service manuals / (and 9 more) and look in the Yamaha section .

I've never tried it. Glad it worked for you; but I'd keep that new box handy. As long as you're riding with at least one buddy and not too far off the beaten path I'd leave the resurrected box in the machine. It may live on forever or it may die tomorrow, but that can be said about just about everything.

Try running a hose from the overflow to a small bottle to catch the water. . If the hose in the bottle stays below the water level in it , it will draw back as the engine cools . If it continues to push out it could be a very small leak on the head gasket .. One just enough to allow combustion gasses to push out , but not large enough yet to allow water to get into the cylinder. If it only does it for a short while after you fill the rad to the top , it might just be the excess water being pushed out past the pressure cap as the motor heats up. If that's the case, it will stop bubbling once the motor is fully up to temperature.. When the motor cools , water will be drawn back in. After it does that for a few cycles , you should not see any bubbles in the overflow bottle, only the level change a little as it heats and cools . Continued bubbles would indicate a head gasket going bad , or less likely , but possible , a small crack in the cylinder or head if the rad did not have antifreeze in it and froze. \