PEAK SEEKER
Active VIP Member
Hey folks, I've been having problems with my Pro; I just bought it back in December and have only had 1 of 3 trips go well with it.
This is going to be very lengthy and drag on, but bear with me here.
It's a 2014, with an RK-TEK 858 big bore w/ boondocker fuel controller and team tied secondary clutch.
The very first trip (two full days of riding) it ran well, but would hesitate slightly at 6900rpm only on the trail, but it would pull about 8200rpm all day after that no problem.
The only thing that changed between this trip and the second is that I put the spare belt into its holder, where it pushed up against where the wiring loom for the boondocker box was poorly routed (not by me).
Now the real issues started the second trip, when I unloaded it off of my sled deck and into our trailer, it barely had the power to do so and was bogging quite heavily. When we got to Golden it didn't even have the power to get itself out of the trailer. After pulling it out by hand and swapping the plugs it seemed to run fine. But about 2km down the trail the thing wouldn't push past 6900rpm, and if I held it WOT (wide open throttle) it would stay at that rpm and start bogging, unless I let off and let it run under 5000rpm or so for a bit, where it would smarten up and run smoothly back up to 6900 rpm. Now if I held it WOT it would bog to the point that it would foul the plugs and would hardly move, and would backfire continuously until the plugs were swapped and the whole process would repeat itself. Also the PTO side plug was fouling up, yet the Mag side plug stayed in decent shape. Eventually it brought up a code, that if I remember correctly said that the Mag side injector was shorting to ground.
So after getting it home, I brought it to Discovery Motorsports in Saskatoon after being told that they had lots of experience with boondocker boxes and the whole aftermarket world. All they did was unplug the boondocker and tell me it was the issue and then they read the code and tell me to fix it myself as they didn't want anything to do with it.
So I went through all of the boondocker box's connections with a fluke and made sure they were good, I found one suspect connection and righted it. I then rerouted the boondocker box's harness, and mounted the box on the hood, and removed the electric start, and installed a tether. I did a few test rips at home, but couldn't pull past 7000rpm for any length of time. But I figured maybe it had something to do with being clutched for a much higher altitude, so I figured it'd be best to test at altitude.
So now this gets us to this past weekend. We were in Fernie, the same place where the first trip I had on the sled a few months prior. I went to ride up the trail, thinking I had magically fixed all the issues. But as soon as I tried to get the sled up past the 6900-7000rpm mark, the exact same issues as before happened. So we packed it up and hauled it to Pincher Creek where I bought the sled and told them everything that was happening. Here's a list of what the mechanic determined:
So he gave me a new set of injectors that we threw in the sled that same night in the trailer. With it up on a lift, it would pull up to 8100 rpm, but not all that smooth. So doing all that we could at that point we figured a test run on the mountain would be the best way to determine how much the new injectors helped. It smartened it up quite a bit, and it would pull 7900rpm (after yet another new set of plugs), however, if I held it WOT it would bog temporarily and drop RPM, then pull back up to 7900rpm, and throughout the rpm range it felt like it was lacking in power. Now according to RK-TEK, these engines should be able to pull 8500rpm when they're happy. So I knew the sled was still having issues.
So we got back home last night, and I tore into the sled this morning to look into some possible causes. First I did a test run to see what rpm I could pull, now it wouldn't get over 6900rpm, and had all the same issues as before. So I pulled the exhaust valves and cleaned them. And found that they had some scoring, is this normal? It doesn't seem like it'd help my issues at all. As well as the keeper washer and sliding washer thing under the bellow on both valves being scored from what looks like vise-grips. Also, the top of the pistons looked pitted, but had a rough film that could be easily scratched off. And the plugs looked like it was running a bit lean. I'll post pictures of all these things at the end.
Both valves had scoring, but the Mag side valve was worse.
Here is the scoring from pliers/vise-grips on the bellows keeper. Both valves had scoring like this.
Here's what the plugs looked like this morning, slightly grey, so possibly too lean?
These are the best pictures I could get with my phone. In the last one you can see how this porous film could be scratch/wiped off pretty easily with just a small led pen light.
So as of right now, here's my thoughts on what the issues could be:
So tomorrow I'm going to have the dealer check out my TPS to get that knocked off the list, if that doesn't get me anywhere, then I'm going to order the stator and swap it out.
Does anybody have any ideas as to what else the issue could be? Or any experience with this kind of problem? I'm getting a little desperate, and quite frustrated with this sled.
On a side note, what does everybody run for adjustable clutch weights? What'd you pay, and why did you pick them?
Thanks for any input! - PEAK SEEKER
This is going to be very lengthy and drag on, but bear with me here.
It's a 2014, with an RK-TEK 858 big bore w/ boondocker fuel controller and team tied secondary clutch.
The very first trip (two full days of riding) it ran well, but would hesitate slightly at 6900rpm only on the trail, but it would pull about 8200rpm all day after that no problem.
The only thing that changed between this trip and the second is that I put the spare belt into its holder, where it pushed up against where the wiring loom for the boondocker box was poorly routed (not by me).
Now the real issues started the second trip, when I unloaded it off of my sled deck and into our trailer, it barely had the power to do so and was bogging quite heavily. When we got to Golden it didn't even have the power to get itself out of the trailer. After pulling it out by hand and swapping the plugs it seemed to run fine. But about 2km down the trail the thing wouldn't push past 6900rpm, and if I held it WOT (wide open throttle) it would stay at that rpm and start bogging, unless I let off and let it run under 5000rpm or so for a bit, where it would smarten up and run smoothly back up to 6900 rpm. Now if I held it WOT it would bog to the point that it would foul the plugs and would hardly move, and would backfire continuously until the plugs were swapped and the whole process would repeat itself. Also the PTO side plug was fouling up, yet the Mag side plug stayed in decent shape. Eventually it brought up a code, that if I remember correctly said that the Mag side injector was shorting to ground.
So after getting it home, I brought it to Discovery Motorsports in Saskatoon after being told that they had lots of experience with boondocker boxes and the whole aftermarket world. All they did was unplug the boondocker and tell me it was the issue and then they read the code and tell me to fix it myself as they didn't want anything to do with it.
So I went through all of the boondocker box's connections with a fluke and made sure they were good, I found one suspect connection and righted it. I then rerouted the boondocker box's harness, and mounted the box on the hood, and removed the electric start, and installed a tether. I did a few test rips at home, but couldn't pull past 7000rpm for any length of time. But I figured maybe it had something to do with being clutched for a much higher altitude, so I figured it'd be best to test at altitude.
So now this gets us to this past weekend. We were in Fernie, the same place where the first trip I had on the sled a few months prior. I went to ride up the trail, thinking I had magically fixed all the issues. But as soon as I tried to get the sled up past the 6900-7000rpm mark, the exact same issues as before happened. So we packed it up and hauled it to Pincher Creek where I bought the sled and told them everything that was happening. Here's a list of what the mechanic determined:
- The fuel controller isn't the issue, he tried multiple boxes with multiple tunes
- The compression is good
- The fuel pressure is good (How do they test the fuel pressure??)
- The exhaust valves are good
So he gave me a new set of injectors that we threw in the sled that same night in the trailer. With it up on a lift, it would pull up to 8100 rpm, but not all that smooth. So doing all that we could at that point we figured a test run on the mountain would be the best way to determine how much the new injectors helped. It smartened it up quite a bit, and it would pull 7900rpm (after yet another new set of plugs), however, if I held it WOT it would bog temporarily and drop RPM, then pull back up to 7900rpm, and throughout the rpm range it felt like it was lacking in power. Now according to RK-TEK, these engines should be able to pull 8500rpm when they're happy. So I knew the sled was still having issues.
So we got back home last night, and I tore into the sled this morning to look into some possible causes. First I did a test run to see what rpm I could pull, now it wouldn't get over 6900rpm, and had all the same issues as before. So I pulled the exhaust valves and cleaned them. And found that they had some scoring, is this normal? It doesn't seem like it'd help my issues at all. As well as the keeper washer and sliding washer thing under the bellow on both valves being scored from what looks like vise-grips. Also, the top of the pistons looked pitted, but had a rough film that could be easily scratched off. And the plugs looked like it was running a bit lean. I'll post pictures of all these things at the end.
Both valves had scoring, but the Mag side valve was worse.
Here is the scoring from pliers/vise-grips on the bellows keeper. Both valves had scoring like this.
Here's what the plugs looked like this morning, slightly grey, so possibly too lean?
These are the best pictures I could get with my phone. In the last one you can see how this porous film could be scratch/wiped off pretty easily with just a small led pen light.
So as of right now, here's my thoughts on what the issues could be:
- Stator, it can't provide the voltage at the higher rpm
- Voltage regulator, although this doesn't seem as likely
- TPS, but I don't see why it would cause the engine to run lean
- Primary clutch, broken spring, worn rollers etc. (sled only has 500km so that doesn't seem likely)
So tomorrow I'm going to have the dealer check out my TPS to get that knocked off the list, if that doesn't get me anywhere, then I'm going to order the stator and swap it out.
Does anybody have any ideas as to what else the issue could be? Or any experience with this kind of problem? I'm getting a little desperate, and quite frustrated with this sled.
On a side note, what does everybody run for adjustable clutch weights? What'd you pay, and why did you pick them?
Thanks for any input! - PEAK SEEKER
