Honda ATV Forum banner
1 - 20 of 27 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter · #1 ·
Hi, my trx recently started acting up during acceleration. kinda sounds like an old jalopy getting a loud constant blap blap blap blap sound and losing it's mojo.

I pulled the sparkplug and its loaded with carbon so I tried changing the plug that worked pretty good for about 2 days of riding then it started over with the same thing, now when I tried a new plug it starting fouling out almost right away.

I have a Clymers manual for my Kawasaki Lakota and it says for fouling out like that theres probably an issue with the carb or with the timing being off.

I guess this would still apply to this quad. is there a way I can check the timing without a portable tach? or perhaps a way I can look to see if the gear is lining up correctly?

And with the carb does anyone know what the proper float height is?

Any other ideas on what to check for would be greatly appreciated.

Thanks
 

·
Premium Member
Joined
·
23,581 Posts
And with the carb does anyone know what the proper float height is?
You might just need to clean the carb. It might just have some debris under the float valve, but here is how to check the float height.

 

·
Super Moderator
Joined
·
18,230 Posts
I agree^^^^ also check the drain plug behind the petcock on the fuel tank. It sounds like you need a good carb cleaning. Also check your choke lever the metal tab that holds the lever into position will wear and cause the choke to be slightly on I've seen this before on these carbs. Also make sure your air filter is good and clean.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #4 ·
Thanks guys, I'll give the carb a good cleaning tonight, I also finally got a hold of the proper spark plug gap size. Seems it was closed too much by .010 hopefully that will make a slight difference as well.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #5 ·
Well I just got around to taking apart the carb and cleaning it really good last night. All the jets and everything looked clear, the fuel is flowing smoothly and the float was fine. Put it all back together and no change

What gets me is it'll idle perfectly then about 1/2 throttle it'll start sputtering. try to hammer the throttle and it'll die altogether. Maybe the ICM is dying.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #6 ·
Another thing about the quad is the battery is dead so I generally pop start it, the lights when idling and or riding flicker a lot but when I was jump starting it with the car today the lights were constantly bright, Does this sound like an issue with the stator? Seems like the quads not getting enough power from running with the stator alone.
 

·
Premium Member
Joined
·
23,581 Posts
If the battery is completely dead, the lights will usually flicker like that. I would try a new battery, maybe that's the whole problem with the sputtering.

If you put a good battery in, you can use a voltmeter and check and see if it is charging right.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #8 ·
It was still doing the sputtering while I had my car hooked up to it. I have a new battery but don't want to install it yet. I read the voltage on the coil and got 120V which is good but on the regulator side all I got were phantom readings, so I'm thinking that would be a good place to look for the issues.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #9 ·
Hi all I'm back. 7 months later and the quad is still acting the same, I've tried replacing the rectifier on the back of the quad, no change and replaced/tested everything connected to the wiring harness except for the ignition module, I'm really hesitant to replace that due to the high cost of the part, can anyone tell me if that goes bad would my symptoms be the same? sputtering and fouling out the plugs instantly.
Before a new plug would last 2 days now a new plug fouls out as soon as I start the engine.

Getting ready to fix it with a special tool, a firecracker in the gas tank lol

Thanks
 

·
Registered
Joined
·
3,003 Posts
Hi all I'm back. 7 months later and the quad is still acting the same, I've tried replacing the rectifier on the back of the quad, no change and replaced/tested everything connected to the wiring harness except for the ignition module, I'm really hesitant to replace that due to the high cost of the part, can anyone tell me if that goes bad would my symptoms be the same? sputtering and fouling out the plugs instantly.
Before a new plug would last 2 days now a new plug fouls out as soon as I start the engine.

Getting ready to fix it with a special tool, a firecracker in the gas tank lol

Thanks
I can't say for sure, but that's exactly what happened to my TRX250EX. It would die after 2 minutes. Pull the plug and no spark. Replaced the plug, start it up, runs for 2 minutes and dies. Pull the plug and ground it to engine, no spark. Did that 3 times before I realized a fairy in there wasn't going to magically stop fouling the plugs. Took it to the dealer and they replaced the CDI. No issues since!

One thing you might be able to do is find a buddy with a 400 and put his CDI in yours and see if it helps. I don't know if any other model CDI will work (300/250 etc), but unless you know for sure, I would stick with another same year 400EX.
 

·
Registered
Joined
·
3,003 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter · #12 ·
might have to go that route... it's just hard dropping more $$$ for parts if they are not going to make a difference... one thing with mine, I never loose spark it'll stay running and idles like a champ but just cant ride it without it hesitating and going blap blap blap
 

·
Registered
Joined
·
3,003 Posts
might have to go that route... it's just hard dropping more $$$ for parts if they are not going to make a difference... one thing with mine, I never loose spark it'll stay running and idles like a champ but just cant ride it without it hesitating and going blap blap blap
Yeah, I thought you said yours fouled the plug. It's nothing like mine. Mine was on like a timer. Weird. I didn't know enough about them at the time, so I just took it to the dealer. I would be hesitant spending that much money on it too, if it wasn't a guarantee that it would fix it. Do you have any friends or fellow riders that will let you put their CDI in?
 

·
Registered
Joined
·
3,003 Posts
I went back through and read your post. I think Helmut was right. You should click the link in my sig and read about the carbs and how to read spark plugs. 1/4 to 3/4 is the Mid range Circuit (Jet Needle, and Needle Jet) and WOT would be your main pilot jet. The reason your quad runs fine for a few minutes is that the plug has a good spark, it hasn't yet been completely soaked. Immediately after it starts sputtering, you should shut it off and pull the plug. Is it wet? A black plug means it is running rich. I would get a carb rebuild kit, or take EXTRA EXTRA time and clean that carb well. Better than you did the last time. Soak all the jets in carb cleaner. (submerge them all)
 

·
Premium Member
Joined
·
4,389 Posts
Correct me if I'm wrong but can't bump starting it cause the timing to slip if you do it a lot? I thought I had heard that before somewhere. And if so your symptoms sound like timing to me.
 

·
Super Moderator
Joined
·
38,618 Posts
Correct me if I'm wrong but can't bump starting it cause the timing to slip if you do it a lot? I thought I had heard that before somewhere. And if so your symptoms sound like timing to me.
i've never seen a bike lose timming from bump starting..i guess it can happen...as for it did happen..i doubt it..if it did lose timming.it would not even idle. the c.d.i's control the timming..well..in a way they do..they tell the coil when to fire the spark plug..this is just part of the process..the rest involves pick up coil..timming chain..flywheel..but..as for his running @ idle..it's not the timming. the c.d.i is the brain behind a motor running..it has alot programed into it, rev limiter..timming..along this line.
 

·
Registered
Joined
·
3,003 Posts
I haven't heard of that, but I guess anything is possible right? I sure would like to know if that could cause timing issues. What I can say is that I don't think his timing is the issue, or it would be hard to start/not start at all. His issue is with 1/2 to WOT. At least that's what I suspect. I'm thinking he may need to replace the jet needle or check it.

I can see right now, that it is very difficult to troubleshoot over the internet! Good Luck!
 

·
Super Moderator
Joined
·
38,618 Posts
first thing you need to do..is go through your carb..make sure it's spotless !!..then check your valves..yes..if the valves are out of sink..they won't let your motor run right. check your compression..this is where your valves come into play. check your timming chain slack adjuster..make sure your timming chain is tight.
 

·
Super Moderator
Joined
·
38,618 Posts
I haven't heard of that, but I guess anything is possible right? I sure would like to know if that could cause timing issues. What I can say is that I don't think his timing is the issue, or it would be hard to start/not start at all. His issue is with 1/2 to WOT. At least that's what I suspect. I'm thinking he may need to replace the jet needle or check it.

I can see right now, that it is very difficult to troubleshoot over the internet! Good Luck!
you pretty much said what i did on it runnng period !..lmfao..timming is not off..as far as the timming chain goes..or it would not even idle or mid range.
 

·
Registered
Joined
·
3,003 Posts
first thing you need to do..is go through your carb..make sure it's spotless !!..then check your valves..yes..if the valves are out of sink..they won't let your motor run right. check your compression..this is where your valves come into play. check your timming chain slack adjuster..make sure your timming chain is tight.
Yes, true, just thought of something while reading this. He said 7 months later. Replace the fuel and do what shadetree said...clean that carb spotless. Put them in a bath of carb cleaner after removing all plastic and o-rings.
 
1 - 20 of 27 Posts
Top