Picked up a Fushin 90 for basically nothing and I'd like to get it going for my son,

When I tested it while purchasing it, it cranked, but wouldn't start and I assumed it was dirty carbs. Brought it home, and they were dirty as hell.. I cleaned them, put everything back together and now I have no ignition at all..nothing. Before it was cranking fine. I've checked the wiring harnesses and they appear to be OK, I bypassed the kill switch so it isn't that (unless there's something weird about it)

theres at least 2 electronic moduals (I don't know what they're called) between the battery and the starter solenoid, I'm wondering if one of those are bad, if theres any way to test, and where to get parts for this thing, a quick search brought me here:

70cc to 90cc ATV - $49.00 : Chinese ATV Parts

Is there some way to jump the starter to get it working??

Let me know what you guys think!

thanks in advance

 

What do you mean by "no ignition at all" coupled with "before it was cranking fine"? Are you trying to say you have no spark? Or is the starter motor not turning when you push the start button? Or it cranks but just won't start and you don't know why?

Whenever someone says they "bypassed" the kill switch that is a big red flag. Exactly how did you bypass the kill switch? If you shorted across the kill switch wires then that's wrong. Kill switches (there is usually more than one on chinese quads, and often three or four) are disabled by unplugging them, or disconnecting wires, but not shorting them.

There is nothing between the battery and the solenoid but a big fat red wire. There is nothing between the other side of the solenoid and the starter motor but another big fat red wire. There are two smaller wires on the solenoid that actuate the solenoid. When you say there are two modules between the battery and the solenoid are you referring to the small wires or the big wires? Is it possible that you misidentifying the solenoid?

Follow the big fat red wire from the battery positive terminal to the solenoid. Follow the other big read wire to the starter. Then go back to the solenoid and short those two big terminals together with a screwdriver (don't mind the minor sparking). Does the starter turn? If so, turn on the ignition, turn off all kill switches, and repeat the screwdriver test. Does the quad start?

 

Thanks for the quick response.

Let me clarify. Before, it would crank but no start. Now, I get nothing when I press the button at all(as if theres a wire disconnected). No noise or anything.

I'm so happy to hear you say that!! I couldnt get the kill switch up I to stay down, I think it may just be very warn. Is there some way to bypass it easily? I just jumped the wires together. How do these switches work then?

I guess I just meant there looks to be two electronic moduals on the bike, and I was thinking one may have gone bad. Now that you tell me I can't jump the switch together, I fear it may be that.

I will try your suggestion and report back, thank you for your help thus far!

 

and btw, yes, I misidentified the starter with the solenoid.

 

You've got two things going on here:

1) The starter doesn't turn the engine.
2) You've got problems with, and have messed with the kill switch(es).

These two are not related. Let's start with the starter motor not turning the engine:

Starter not Turning:

Turn on the ignition switch. Turn on the headlights. Jump the quad battery to your car if necessary. Do the headlights light up? If no, then check the main fuse, look for loose wires around the ignition switch.

If the headlights do light up, then step on the brake (ignition switch still on). Try both front and rear brakes. Does the brake light light up? The brake light *must* be on before your quad will crank the starter. This is a safety interlock that keeps you from starting up the quad in gear and lurching unexpectedly. If your brake light is not on then maybe the switch needs adjusting. These are notoriously finicky.

Kill Switches:

Kill switches don't keep the starter from turning. Instead they kill spark at the spark plug, keeping the engine from starting. The engine will crank and crank with the starter motor, but just won't fire. Obviously you need to get the starter motor cranking first before tackling kill switch problems.

Kill switches work backwards form how most people think of switches. When you short the two wires of a kill switch together you are actually shorting a high voltage (but low current) power supply inside the CDI (which generates spark) to ground. This kills spark generation. Opening the switch allows the high voltage supply to build up in the CDI and generate spark. Thus to bypass a kill switch you unplug it, not short it.

There are up to four kill switches on chinese quads. They are all wired in parallel - such that *any* kill switch which is shorted will kill the spark regardless of how the other kill switches are positioned. Not all quads have all these switches, those that don't are just missing them. They are:

1) Ignition switch: One half of this switch shorts the kill wire to ground when you shut the quad off. This is why your quad stops when you turn off the ignition.

2) Left Handlebar Kill Switch: When you activate this switch the quad stops. In an emergency this is easier and safer to use than reaching for the ignition switch.

3) Tether Cord Pull Switch: A safety switch which is held in an open state (disconnected, or not shorted) until a plug is pulled out. This plug is tied to the rider or tied via a long cord to an adult surpervising a child. To get spark you must have this plug inserted firmly.

4) Remote Control Module: This is a radio controlled device that allows remote start up and remote killing of the engine. This is mostly installed on smaller quads designed for kids.

Hopefully this will get you started in the right direction. If things look like further help is needed then get yourself a voltmeter and prepare to learn how to use it (with help of course).

 

thanks for the plethora of information.

I've got it running now, I had to jump the solenoid with a screwdriver. The switch does not work. Does this mean the solenoid is bad??

Also, when it turns over, it takes off. I have to kill it quick other wise it causes hell, lol.. its stuck on like WOT - do these things have a neutral? or no? it doesn't appear to me that they do. I disconnected the throttle cable (from the thumb end) and pushed it in the carb as much as possible (in theory so that it would sit still when I started)...but it still wants to take off. Why do you think this might be? Can I disconnect the throttle from the carb and start it without and problems? or would that be like WOT?

Also, when it took off by itself the first time, it flipped over (hit something) and broke the brake handle mount right in half Can I order these from somewhere? I'm going to see if I can make it work, but chances look slim.

thanks for your help Lynn.

 

also Lynn, if you could tell me how to go about tightening the chain, that'd be great. Does it involve pulling the swing arm out?

 

Does your solenoid go "click" when you push the start button? If yes, then most likely the solenoid is bad. If no, most likely it is something else. So what about the headlight test from the last post? Brake light test as well? These will answer a lot of questions.

I don't claim to be an expert on carburetors. So take any advice from me with a grain of salt. I've read elsewhere that if the piston/slide from the top of the carb is installed backwards it will go full throttle when it starts up. Try this link for a youtube video on how atv carbs work:

YouTube - how motorcycle and atv carbs work

I wrecked my quad a couple years ago and had no trouble finding the same broken part for my quad in several places on the internet. The economy has made it a bit tougher these days so I can't say the same is true today. But I would still search around.

 

Thanks Lynn!

the solenoid makes NO sound. I will try the lights test tomorrow, I had to clean up yesterday after the mess it made (lol) and then my son was coming home from school so I couldnt work on it any more (gonna be a surprise) so today or tomorrow I will check.

again, happy to hear you saying that! haha I had the throttle cable in and out 2 or 3 times, its very possible that I put it in backwards. I will try it

yes, I've searched and already found a replacement for cheap, which is great. Thanks again and I'll post back with more results... soon

and Lynn, do you have any advice for tightening the chain? thanks.

 

On most quads the swing arm holds an axle assembly which includes the axle bearings and the bearing housing. This assembly is held in place with four bolts onto the swing arm. Two are pivots (the upper two), an two bolts are in slots (the lower two). You need to loosen all four bolts, then pivot the whole axle assembly back using the pivot points and the slots. There are two adjuster devices sticking out the rear of the quad that you tighten with a wrench that pulls back on the axle assembly. If you can't identify these then go to ebay and search for "chinese atv chain adjuster" for a picture. Tighten all four bolts when you are done.

A less common method uses an axle assembly where the axle and axle bearings are mounting in a cylindrical housing where the axle is off center with respect to the axle housing axis. In this case you loosen a housing clamp and rotate the axle housing, which rotates the off center axle through an arc which changes the chain drive length. Then you tighten the clamp back up.

Don't overtighten the chain. When the rear suspension compresses it tightens up the chain. Make sure you leave an inch of deflection in the chain to allow for the tightening during bumps.