Quadzilla XLC 500 Engine Issues

[Zilla28]

While riding my Quadzilla XLC 500 I was cruising along about 60 mph then opened it up, but once I hit 70-75 mph it died on me so I rolled to a stop and it wouldn't start for about 20-30 seconds. I then noticed the Temp light occasionally flashes on but its so quick you wouldn't notice in the day so not sure how long its been happening. The engine has started pinging when I accelerate which can be caused by many things so I drained the fuel and replaced with hi octane, fitted a new spark plug, adjusted the little washer on the high jet in the carb twice to make it run more lean which made no difference.  I tested the thermostat which opens at the correct temperature, I removed the radiator cap and started the engine and no bubbles were showing and the oil is on maximum and very clean as I have not long serviced it.

The last time I took it out I went 14 miles and the coolant in the bottle has dropped about 1/2".

I am now leaning towards a head gasket and have purchased a full gasket kit but was wondering if there's anything else it could be before taking the engine apart.

[Frank Angerano]

Have you checked to see that the cooling fan is coming on ? And if so is the radiator clean ? Also look up and see if the engine shuts down on the hot side. When it’s at that point is it killing he engine. And btw dam that’s fast ! Slow down a bit brother! 

[Zilla28]

1 hour ago, Frank Angerano said:

Have you checked to see that the cooling fan is coming on ? And if so is the radiator clean ? Also look up and see if the engine shuts down on the hot side. When it’s at that point is it killing he engine. And btw dam that’s fast ! Slow down a bit brother! 

Yes the fan does come on but not every time and I have not had a close inspection of the radiator but it should be clean as I pressure washed it and have only used it on the road. I have no temperature gauge on my display so I can't see how hot its running.

[Frank Angerano]

Ok great.  What about the water pump it could be possible that there is no circulation? You can buy an infrared thermometer and shoot the head to see temperature under the same circumstances. 

There can only be a few things going on here 

1. Thermostat 

2. Water pump

3. Cooling fan/temperature sensor that brings fan on.

If you have a bad head gasket the oil will be discolored (greyish) in the crank case and a lot of white smoke.  

 

[Zilla28]

But I don't know what its suppose to run at and what is classed as too hot. The thermostat is fine as I tested it and it opened at 71 degrees which is stamped on it. If the coolant on the tank has dropped by 1/2" after 14 miles of riding it must be going somewhere which is leading me to think the head gasket but im hoping its not.

[Frank Angerano]

It’s not supposed to really go over 160 I would think on a good day. Have you checked the oil for color ? And also is there a leak you are not seeing ? And the water pump... you should see that coolant flowing with the cap off the radiator after it’s good and hot. If not I’m thinking the water pump. And the seal on the water pump as well and that’s why your loosing coolant. 

[Zilla28]

I've not checked the oil for colour, only looked at it on the dip stick. I will try and find time to check the water pump tomorrow as I do have a new water pump seal in my gasket set.

I just remembered, last time I warmed the engine up the pipe from the water pump to the bottom of the radiator was warm and I could hold it but the pipe from the top of the radiator to the engine was too hot to hold.

[Frank Angerano]

Yea brother I think it’s a pump issue. Never know but that’s where my guess is. The good thing about these problems are the limited things it can be when it comes to a water cooled system so get after it and narrow it down so we can get this figured out and get back to riding!!!  Let us know how you make out.  

 

 

[Zilla28]

OK today I removed the water pump cover, dained the engine of coolant and turned the engine over and the impeller is spinning ok. The gasket on the cover was knackered but I didn't want to replace just that gasket as I had not seen any leak from the cover which makes me think it must be leaking internally. I have managed to remove some of the internals but cant get any further.

What I expected to take a few hours looks like its going to take much longer.

Do I need to split the crank case to remove the rest?

Edited December 3, 2018 by Zilla28

[Frank Angerano]

Was the impeller spinning or just the shaft?  I’ve seen the same thing and when the bike was being cranked the owner was able to hold the impeller and the shaft spun not the impeller  so make sure that the shaft and impeller are not slipping   

That back end of that shaft looks chewed up. What goong on in there ?

Heve yiu checked the oil ? Any coolant in there ? 

That seal on the back of that impeller looks shot and could be leaking fluid into the crank case.   

[Zilla28]

As far as I am aware the impeller was spinning with the shaft as it was locked on to the shaft, not overly tight but tight enough.

I saw some videos online of people removing the pump seal and the only way they could remove it was to prise it out with a screw driver so that's what I done, hence the reason it looks a mess.

The oil does look a little watery and I done a test with dropping the oil in a hot saucepan to see if it bubbled which it did, so this confirms there is antifreeze in the oil 😞 

[Frank Angerano]

I can see by the color it looks as if there’s coolant in the oil.  So now it’s on to find out where it’s coming from! 

[Zilla28]

OK, I have finally got somebody to change the head gasket on my quad and also needed to have the valves seated as one wasn't closing. All is now back together but when I took it for a test ride it's still pinging and the Temp light still flashes on.

I guess the engine will need to be taken out again and to split the crank to inspect the water pump? 

[Frank Angerano]

You should not need to take the engine out or split it to replace the water pump.  I would have done that while the head was off just to eliminate the possibility of it being bad.  But no way should you have to pull the engine or split it open.  

[Zilla28]

The water pump seal has also been replaced after me trying to remove it and making a mess of it. I am beginning to think it's something internal within the case that's making the impeller not function but im no mechanic so have no idea. Just very frustrating having only owned it for 5 months and its been off the road for a month.

[Frank Angerano]

I know it’s frustrating.  Take a deep breath.  Is the shaft spinning when you crank the engine ? 

[Zilla28]

Well the impeller was before (video posted above) but I didn't check the shaft.

I just removed the thermostat and took it for a 10 mile test ride, it's still pinging but I didn't notice the Temp light come on. I will have to check the shaft on the impeller tomorrow.

I notice the top pipe on the radiator gets very warm but the bottom pipe is hot. Surely it should be the other way around 🤔

[Frank Angerano]

If you took that bike for a 10 mile ride and the temp light didn’t come on and the bike didn’t over heat then it should be good.  I’ve seen instances where you have what’s called an “air bound” system.   It’s essentially a stuck airball in the system that takes a big push of water pressure to push it through the system.   Much like an air bound radiator in your  house on a hot water heating system.  Only difference is that home radiators have bleeders on them to get the air out.   It’s very posable that this happened.  So just keep an eye on it and you can look inside the radiator cap for fluid movement which will only happen after the thermostat  is open.  Take the cap off and start the bike and after about 10 min or so the water should start to flow.   Is the cooling fan coming on properly also ? 

[Zilla28]

I let the bike idle from cold for 6 minutes to gently warm up, took it for a 10 mile ride and turned it off when I got back. After a few minutes I started it again letting it idle and the fan kicked in so I turned the quad off and let the fan do its job but it's the engine pinging which is worrying me as I can't afford to spend much more money on it if I end up knackering something else by riding it with a pinging engine.

[Frank Angerano]

What are you running as far as octane high test ? If not boost the octane.  See if it stops.  Also when you put everything back together was the timing spot on? That’s important. 

[Zilla28]

I use to run Unleaded but when it started pinging a while ago I drained the tank and filled with Super Unleaded.

My mate done all the mechanical bits for me and yes the timing is spot on according to the service sheet from Quadzilla.

[Frank Angerano]

Ok I would recommend high test and maybe an octane booster if need be.  See if it goes away. One last thing I would check is the quality of your spark. Make sure it’s a strong blue spark and the gap is correct. And the pick up coil, ignition coil are in good shape.  The quality of the spark will tell you. 

[Zilla28]

Today I noticed the coolant in the radiator was filthy so I drained and flushed the radiator and checked the colour and spark on the plug which seems fine and also tested the water pump by touching the impeller when the engine was running and by removing the cap on the radiator I can see its pumping fine.

 

 

I called Quadzilla and they said it must be a fueling issue.

As running lean can cause pre-ignition I adjusted the needle to run as rich as I could then took it for a 10 miles ride and still the engine is pinging. I added half bottle CVL turbo octane booster which is suppose to prevent pre-ignition but no luck.

 

 

Edited January 21, 2019 by Zilla28

[Frank Angerano]

Nice work. Try to raise the clip on the needle and see if the pinging changes. It’s going to take some testing and time but it will be dialed in.  Only thing I can go back to is the timing. I know you said it was all good just double check.  Can’t hurt.   

[Frank Angerano]

By the way that plug should be a toasty brown.  Was that a new plug ?  Or newly installed ? 

[pokerl0w]

5 hours ago, Frank Angerano said:

By the way that plug should be a toasty brown.  Was that a new plug ?  Or newly installed ? 

is this what you mean by "toasty" - a dark/bold coffee bean color? (not the optimal one)

[Frank Angerano]

The optimal color has that brown toasty looking tip on it. See that light brown? That’s what I’m talking about.  

[Zilla28]

That was a new plug.

I then set the jet so it was running richer and put a new slightly cooler plug in which came out very brown.

Now I have leaned the jet off a bit, took the carb off and tried to give it a wash with petrol and blow it out but couldn't really get to much. I took it for a ride and the Temp light flashed once and the engine pinging is still there. Not quite as bad but still noticeable 😕 

[Frank Angerano]

Wow that’s a funky color plug.   So not to confuse the two, the temp light and the pinging are two separate issues and one should have nothing to do with the other.   

Having said that it seems like your slowly making improvements and getting it dialed in.  The only thing I can add at this point is to keep making small changes in the carb and get it as close as possible and keep track of the changes so you can go back should any new changes make things worse.  

As for the temp light thing it’s just a matter of coolant running through the system and creating dead/hot spots where the sensor is would be my guess. Especially since you said you took it out for a few 10 mile rides without over heating.   

I hope your keeping some tools and extra fluids like coolant out on these long rides. 

[Zilla28]

Yeah I usually always ride with a backpack with all the tools I need for removing screws and adjusting the chain 🙂

I have just been reading about the carb settings and I may have found the issue. I remember when I removed the pilot jet I wound it all the way back in as (I think) it was already like that. I will have to remove the carb again and set it to 2.5 turns out which is factory setting. Hopefully this will cure the pinging, although it use to run fine when I bought it and before I took it out 🤔

Only one way to find out.