Does anyone have a guide or video on how to change the oil in the Vortex ROK GP?
How frequently does the oil need to be changed?
Thanks!
It’s a 2 cycle engine, there is no oil in the engine. Only the oil that you mix with your fuel.
@Rapid1 That is incorrect. It does have gear oil to lubricate the balance shaft that should be changed regularly.
@Jgbedford, the drain plug will be on the side closest to the engine. Depending on how new your engine is, it’ll either have a clear sight glass in it or be just a regular solid aluminum plug. There’s also a 5mm bolt that’s lower on the engine that you can drain any extra oil out of if it all doesn’t come out of the main drain plug.
You can either fill it through the drain plug by tipping the motor on it’s side or through another plug that’s on the top of the case right next to the exhaust. I want to say it’s 100cc of 75w90 but I’m not 100% sure off the top of my head. I would change it at least after every race weekend. That way you can keep fresh oil in it and also keep track if you start seeing metal shavings.
Drain plug is red, fill plug is blue.
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Sorry, thought he was talking about crankcase oil. It’s a question I often hear on 2 cycle engines.
Jason,
Here is a link to our engine documents https://rokcupusa.com/rules/rok-cup-engines/, you will find the info you need under in the owners manual. As for how often, this is probably the least expansive maintenance item next to cleaning your engine, for me I would do it ever 2 track days, or every race weekend, for sure you can go longer but if nothing else you will make sure the fill levels are correct. Thanks for purchasing Vortex
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Thank you @CourterZT,
I see the plug, but can you identify the 5mm bolt you refer to?
Is it as simple as removing the plug, letting it drain, and refiilling through the fill plug after reinserting the drain plug? This can be done from a kart stand and does not require the motor to be removed from the chassis, right?
I appreciate the help!
Hi @Garett_Potter,
I appreciate the link to the manuals, thank you.
I see the type and amount of oil, I must be missing something - I don’t see where the manual specifically shows how to change the oil.
Help?!
The bolt is almost directly below the drain plug, just slightly to the right.
Yep, it can be done on the kart it’s just a slight pain to get to. I normally remove the engine just to make it easier and give everything a thorough clean but it’s not necessary.
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Hi Everyone, sorry with Covid-19 I never got back to my kart until today - I wanted to get it all ready for the summer, hopefully I will be able to get out and use it soon.
I can’t find a drain plug on the side. I took some pictures while it was off of the chasis. I ended up holding the motor upside down for a few minutes, the oil that dripped out (and there wasn’t very much of it) was pretty discoloured.
Hopefully there is an easier way to change the oil if I’m going to start doing it more often.
The one directly in the center of your second picture is the one that should drain (at least it used to). It seems like they also got rid of the sight glass/plug which is odd. If you pull that bolt out you should be able to get some oil to come out still. Unfortunately ROK’s seem to consume gear oil so that’s why it’s so important to keep up on changing it.
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Hey @CourterZT, I did take the crank cover bolts off and one had a copper washer, the bottom middle one as you indicated (maybe this is the drain plug?). I haven’t run the motor all winter, and it was still a cool day in Canada, maybe I didn’t have enough patience to drain it out that way. I’ll have to try that bolt again after a few sessions on a warmer day when we are allowed to go back out and start karting… for now, I managed to get it all back to gether and rev it in the driveway to impress my neighbours ;).
As mentioned, the oil I did get out from turning it upside down was very discoloured (bad me… the sport is new to me and I didn’t realize it reuqired frequent changing). Maybe the drain plug on the bottom of the motor has some sediment collect over the winter preventing it from draining.
I appreciate the help - I got another 75 CC back in there, so I am ready to go when the tracks open back up.
Hey @Jgbedford, do you mind telling me what gear oil you used in your case? The best I could find in writing is in the ROK GP Manual they call for 40W90 oil… I can’t seem to find it anywhere and I’m questioning if its a typo…
Thanks for your help!
It’s impossible to find, I’ve looked everywhere. It drove me crazy! In the end I used motul trans-oil 10w-30 and never had any issues.
Thanks for your help! 10W30 it is.
Cheers
Hi @Bakaboo -
I run Fuchs Silkolene gear oil SAE 90.
When I drained it last, it was really thick so I let it drip for a few hours.
I believe I bought this at Goodwood Kartways.
Never had any issues after 2 seasons so far.
Hope this helps!
Dealing with this oil and the information from Rok (there is none) and on this thread was an exercise in frustration. Garret Potter links to a series of downloads which mentions nothing at all about where and how to drain the oil. Others in this thread talk of 100cc and 75cc of oil, which seems to be 2 to 3 times as much oil as is actually recommended (30cc).
First of all - maybe once upon a time there was a drain plug in these engines, just as once upon a time there was a fill window, but I am convinced no such thing exists on my version of the engine at least. I tried the hole recommended by Zach, it definitely is not a drain hole for me. Also, I found this photo (see below) of the disassembled counter balancer part of the engine, and I don’t see how any of those bolts could possibly be drain holes - the balancer seems walled off from everything else in the case.
In any case, I pulled the engine, flipped it upside down, drained the oil, and then filled it back up with 40cc (10cc to grow on) - until someone can show me photos, a video, or explicit documentation of a different process, I believe that is the only possible way to do an oil change.
Majority of the things while working on ROKs are frustrating. I have little experience with the newer, sight plug-less, version. With the older version you would remove the sight plug to get majority of it out quickly and remove the lower bolt to get the remaining oil. On the case there would be a copper crush washer on that one bolt only to create the seal. They must have ditched that on the update.
The gasket shows where it’d allow oil to pass to the bolt.
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Yeah, that’s what I pulled. Nothing came out. I even started pouring new oil in just to see if I could get it to flow. Still nothing. Also, notice that the counter balancer gears appear to walled off from having oil even reach that area. Whoever can pull that, or any other bolt, and get anything to come out of it congratulations. I never could. (and it sounds like in all probability it’s because I don’t have the same version engine cases)
Yeah that’s one of the most annoying things about the GP. When they deleted the internal water pump they changed the gasket and where the oil goes so it cannot get to the drain hole anymore. The GP also seems to be really bad at losing gear oil to atmosphere so it must be kept up on. I considered cutting the gasket and allowing that lower area to fill up and then be able to drain from that bolt as originally intended. On the occasion we run a GP anymore we just fill up the gear oil almost completely, it spits some out but it’s better than frying a set of gears.
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Thank you so much for that explanation and additional tips for how you deal with it. Ultimately, it’s not that big of an issue. Thanks again. 