Hey, just wondering if any of the gearheads out there could help me out here… I put new spark plugs in my RZR a month or two ago, but for a while it has been an absolute bitch to start, i mean, i have to kick the shit out of i for at least 3 or 4 minutes just to get it to life. I replaced the battery last week too, but this hasn’t helped the problem either… After it’s been running for a while it’s fine, although it does feel kinda sluggish… any ideas?
Did you put them in straight out of the box?
Take 'em out and check the gaps.
Might it be the carburettor?
My Dio used to be a pain to start and it was getting worse then Typhoon Mindulle made it virtually unstartable. One new carburettor and it was right as rain. (Right as no rain, really.)
Cleaning the carb would be a good thing anyway if it hasn’t been done for a while.
Start with cleaning the carburettor. First you look for a screw flush on the side of the carb, right above the float chamber gasket line. That’s the idle mixture screw. Take a screwdriver and turn it gently as far as it will go, counting the turns. Remember how many turns it was, should be between 1 and 1-3/4. Then back the screw all the way out, taking care not to lose the spring behind it.
Clean the tapered end of that screw with carb cleaner, no abrasives. Then squirt a bunch of your carb cleaner into the hole.
Replace the spring and screw, bottoming it out, then back it off the same amount it was originally, or the default position of 1.5 turns out.
The bike will be a bit hard to start because of all the crap and carb cleaner in there, but it will start. You’ll find out the next day if it’s better or not.
General questions:
When was the last time the air filter was cleaned or replaced? When dirty they choke the air flow. When old they crumble and block everything up, and allow all the crap in the air straight in unfiltered.
Does the bike make blue smoke? Does the gearbox oil disappear gradually? The RZ crank seals have a finite life and both sides will leak. The clutch side seal will let oil get drawn in and that will smoke.
When the motor is warmed up, does it idle really high? Rev easy but no power? The alternator side crank seal will let air be pulled into the crankcase and that screws up the mixture. Both these seals can be fixed without removing the engine from the bike.
It’s also possible that after all these years, the coil and/or plug lead are failing. A bad coil may create a fat visible spark outside the cylinder, yet fail to fire under compression. Only way to know for sure is to swap for a known good item. Five minute job.
Good luck.
In old RZRs sometimes the capacitor thingy that generates the spark deteriorates and doesn’t generate enough voltage - chekc the color of the spark - it may not be the plug.
Here’s a similar problem, to which there’s no answer as of yet. I’ll be watching this thread to see if there’s a new idea about it.
My wife had a problem starting after the bike got wet. Here’s what we’ve done so far:
We got the carburetor cleaned.
We got a new starter.
We had the fuel pump replaced as well as the fuel filter.
At that same time, the mechanics put some grease in somewhere to help keep out the water.
Now we have a new problem. It’s horrible to start in the morning. It will start in the afternoons, but in the morning it takes up to two minutes to get it going.
We had the carburetor cleaned, but that didn’t help.
They replaced the carburetor, but the new carburetor didn’t help the problem.
Try the cleaning of the carburetor/adjusting the carburetor/putting in new spark plugs/cleaning or replacing the air filter/checking all the air and fuel hoses.
What else can we do to get our bikes to start?
Thanks for all the info guys, much appreciated! Hopefully this will sort the problem out. Thanks again! 
My idle mixture screw is frozen for all eternity and resists all attempts to free it… 
Same bike, same problem. Fortunately, I live on a hill.
Trapjaw, I’ve heard that parts are more readily available for RZ’s down south than up here. If you find out in the end it’s your carb, can you order two?
Thanks in advance…
WD-40, a moisture/water displacement spray, works wonders for problems like this. It may be a cheap solution to the problem.
Thanks for the advice…Been there done that 
If I can’t adjust the fuel air mixture, then I want to replace the entire carbie. Right now it’s damn hard to start and won’t rev about 7,000RPM. It got significantly worse after the mechanic dumped it on the road at speed… :fume:
[quote=“MJB”]
If I can’t adjust the fuel air mixture, then I want to replace the entire carbie. [/quote]You can adapt a 王牌 or NSR Keihin PE26 carb to fit the RZX for some good power and driveability gains.
You need the 王牌 main jet (IIRC that’s a 128), the NSR needle and the throttle slide. Either idle jet will work ok, though the 王牌 item is optimum. If you get the newer style NSR carb with EGR you’ll have to blank that off. The 130 main jet will work okay, but you’ll have to modify the needle. The late model needle has no grooves to adjust it’s position. You usually need to drop the needle one groove.
The 王牌 carb body has a boss for the oil injection nozzle. Drill it out, extract the original Mikuni nozzle and press it gently into the new body. The NSR already has an oil nozzle, so it’s plug and play.
Last off, the throttle cable has to be modified a little to fit, but it’s pretty obvious.
It’s also possible to fit the 王牌 six-petal reed block, though that’s a bit more work.
I hate to say but that doesn’t sound like a carb problem to me at all. Change the plug and the bike is harder to start? Hmmm… It’s definetly electrical and I would bet money you need a new ignition coil. About 400nt for that bike and it’ll start like a new one again. If the bike starts and stalls multiple times, the engine could be lacking compression or it could the bike could have carburation issues.(low compression causes carb to fail sucking enough gas in.)This kind of symptoms will usually occur slowly and aggravate with time.
Now having loss of performance and hard starts over night because you change the plug is definitely not carb related. It’s an electrical issue and it’s quite common on motorbikes in humid Taiwan.
Good luck!
bobepine
[quote=“MJB”]My idle mixture screw is frozen for all eternity and resists all attempts to free it… 
Same bike, same problem. Fortunately, I live on a hill.
Trapjaw, I’ve heard that parts are more readily available for RZ’s down south than up here. If you find out in the end it’s your carb, can you order two?
Thanks in advance… 
[/quote]
I bought a carb for a RZR in Kaohsiung a while back. If my memory serves me well, it cost just over 2000nt. If you want I can look one up for you.
Edit:[quote=“hsiadogah”]The alternator side crank seal will let air be pulled into the crankcase and that screws up the mixture. Both these seals can be fixed without removing the engine from the bike. [/quote]
The gear oil can leak into the pick up coil as well and it causes troubles reaching high rpm, cause stuttering during acceleration and loss of power as well as difficult starts. The oil doesn’t burn well and the bike smokes more too.
If your bike got worse after being layed dowm MJB, I suspect that a stuck mixture screw isn’t your only problem. It’s really easy to open up the left cover to inspect the seal. You need air tools to remove parts of the pick up coil and then you need the special seal puller to replace the seal. It should be pretty obvious just to open the cover and look for fresh oil deposits without having to touch the coil itself though. It should be bone dry behind that cover. I got that seal replaced and the coil cleaned on a RZR as well and the bike was uncomparably faster and easy to start after that. Cost me 400nt labour included.
bobepine
Bobepine, do you live in kaohsiung? where did you get the parts? I want to know if there are any mechanics down here that specialise in, or at least know a bit about RZRs, since I do need a few other things done to mine. Thanks for all the advice ppl, although I haven’t gotten around to trying any of it yet (been overworked), will try this week sometime. thanks!
Hi trapjaw,
I do live in Kaohsiung, (Tsoying district). I buy my parts from a performance shop on Junghwa road. I know two good mecanics here. I do most of the work myself on bikes though, I have a good machinist near my house too.
Send me a pm if you want, I can send you adresses or I can meet you one weekend and tell you what your bike needs, introduce you to my mecanic and my parts guy. I can fix it for you too but I would charge some labour a bit.(300nt/hr) I fix many bikes for foreigners, fixed three this month alone.
Let me know,
bobepine
Update for MJB’s finicky RZ…It’s dead on the side of the road
Stranded me for a nice 3 mile walk to school, and another 3k up my hill :fume:
Started even harder than usual, then backfired all the way down the hill…Wouldn’t rev over 3k, and then just konked out. Will not start now.
I’m doing two jobs and don’t have any time to tear into it, despite the excellent fix it suggestions supplied on this thread…Thanks especially to Hsiadogah and Bobpine for all the great advice. 
Nobody down here will touch it with a ten foot pole. So now have to figure out a way to get it to Jeremy…If it’s damaged beyond reasonable repair then it’s time for a new machine.
Wife approval for VTEC 400 is pending, but looking good. 
Damn, man, that was your machine I saw on the way up for a bike ride. I remember asking if it was yours or Ironman’s. Mr. He replied, “Neither. Why would either of them park their bikes here. There’s nothing here.” Now I know why.
PS. Very sorry to hear about what happened. Hope you can either fix it or expedite your approval for the bike you really want.
sweet… 
:happybiker:
Pretty soon we will have enough Forumosans with bikes to start a start bike gang. 
I had a good look at trapjaw’s bike today. This is what I found. The spark plug was just the right color and the carb showed no air leaks. Air mixture was adjusted properly and the bike idles very well once warmed up. The bike will rev all the way up quite easily without any stuttering but it doesn’t have much guts at high rev. The bike smokes badly when you accelerate hard. I reduced the oil mix on the oil pump cable by a fraction but it hardly made a difference.
So, the bike has loss of power with hard starts when cold but it has good spark and good carburation. Diagnosis: Worn rings and possibly a nice grove on the piston. We are getting together sometimes soon and we are planning to eversize the engine. We’ll open it up and look at it anyways. All parts including gasket kit, oversized sleeve, new piston, rings, bearing costs 600nt.
Another problem is the head lights. I’ve never seen that before. Only the brights work but the dims do not. The thing is even on brights, they are quite dim as in barely on. I tested the battery at 13.3 volts and the alternator at 15.5 with a reving engine which indicates that it’s not a battery or alternator problem. I guessed that he just needs new headlights for now because that’s what I would do first to see if it solves the problem.
What do you think gents?
bobepine