How To Service The Gearbox On The Rotax Max 125 Engine - POWER REPUBLIC

In this week's video we show you how to service the gearbox and change the gearbox oil on your Rotes Max 125 Engine.
Subscribe here: / powerrepublic
For more information head to our website:
www.powerrepub...
Or check out our social media at:
/ powerrepublic
/ powerrepublic
#POWERREPUBLIC

[@bm7760]

Checked mine yesterday. Must've been all of 20ml of dirty old oil. Kart's new to me. Just refreshing everything. Thanks for the video.

[@PowerRepublic]

Glad to help legend 🤛🤛🤛

[@mugenmrx5]

I'm finding your videos some of the best on KZbin for Karting generally and the additional tips and tricks (outside of the factory manuals particularly) are the most interesting and useful! Keep them coming!

[@PowerRepublic]

Thanks for the positive vibes. Happy new year 2019

[@linadukstaite6046]

I can’t believe I did it my self! Thank you!

[@PowerRepublic]

No problems Lina

[@jordyschoenmakers]

You are awesome, These videos are great! this is understandable even for the recreational karter. This saves me a lot of costs in the future because I do it myself now. Tinkering is becoming more and more fun. Thanks from Holland, Greetings Jordy

[@PowerRepublic]

Hey Jordy, thanks for the positive feedback. Like most things, once you get started it becomes way easier. Do you have any topics in particular that you would like to see on YT?

[@jordyschoenmakers]

@@PowerRepublic Yes, i would like a video on toe-in/toe-out and the effect this has on the camber/caster and a video on driving height would be awesome. thanks

[@PassosPassos-fn1nk]

Your video is very good and I always follow it. I have a Rotax Evo, and it's not going above 94km/h, I noticed that the valve isn't opening and closing correctly, I've already cleaned it and it's still not working. Do you think this is limiting the speed? as it reached 110km/h. What do you advise me to do? Could it be an electronic problem? Is there any electronic test that can be done? Do you have a video about this? big hug

[@mikewebster20]

Hi there What grade oil are you using in the gearbox? 15W40 or 10W40 fully synthetic? And do you recommend a brand when not using rotax oil?

[@alvarobenaventec.7154]

Great video! I'm a huge fan of this channel. Can you make a video explaining your pre-race procedures for a Rotax 125 engine? Thanks once again!

[@PowerRepublic]

Of corse I can, how long have you been racing Rotax engines for???

[@alvarobenaventec.7154]

@@PowerRepublic Not so much time, I have it back home, and I study in another country. But whenever I visit my country I try to use it

[@johnva7]

Awesome, thanks mate, can you please do one on the x30?

[@PowerRepublic]

Sure can, ones coming in next week for a full rebuild. Stay tuned !

[@anthonymitchell2709]

Excellent video, any videos on replacing the water pump seal? thanks mate

[@PowerRepublic]

No but that is an excellent idea 💡

[@anthonymitchell2709]

@@PowerRepublic look forward to it thanks

[@mukilanganesh]

Thanks for the video! very useful. I recently changed the entire clutch kit through a rotax dealer. When i started the engine after clutch replacement, the sprocket is rotating in the reverse direction. I checked the battery terminals and electrical, all looks good. You mentioned in this video that the gear must be aligned at piston TDC. Does this affect the ignition timing? Could you please advice?

[@PowerRepublic]

Hey mate, nah not sure on that one. if the gears are off it should only effect the balance of the motor. the timing is set with the ECU or coil in older models. I have never seen an engine running reverse directions. maybe take it back and just ask them, there might be a simple explanation as the engines are pretty reliable

[@juanvaldesz7603]

Hi, great video. I just serviced my Rotax 125 Senior DD2 (150ml of oil). I think I put a bit too much oil into it, since it says in the instructions manual that the oil level should be 1/3 of the oil level window and I thought 150ml seemed to be too little. Do I need to do it all over again and make sure I only put 150ml of oil in? I would say it reads between 1/3 and 1/2 in the oil level window now. Thanks in advance 😅

[@PowerRepublic]

I use 150ml’ so you should be sweet. Maybe there was a little left in there that makes it look fuller. I say send it !!

[@jesperek6402]

Yep this was the video I was looking for, but you didn't say anything about how hard you put the screws back on to the cover of the gearbox, and it was fastforward 😐 but it looks like very little force tho 🤙

[@PowerRepublic]

Normally for a M6 Cap Screw it is 10 Nm's, but hand tight with the small end of the Tee Bar will be fine. I will tighten up the Video Producer for you for fast forwarding the critical section ;)

[@JuanGonzalez-oo6hf]

So when aligning the gears, will it give you more speed and power on the long road?

[@Arvid.p.Albinsson]

This is great, just Hope that my engine is the same.

[@PowerRepublic]

yeah it should be, what motor have you got?

[@Arvid.p.Albinsson]

@@PowerRepublic the same it turnés out, have done the job

[@PowerRepublic]

@@Arvid.p.Albinsson perfect !

[@mugenmrx5]

Great videos keep them coming! One question is why do you guys run ATF fluid as gear oil in the ROTAX engines instead of the 'proper' Rotax gear oil? Do you use the ATF oil in the DD2 engine gearbox as well?

[@IggySport1388]

Derek some insight here would be appreciated because in addition to what he's said there's also the fact that on the gear cover it says you can also use 30 weight engine oil, so that's three different options...the rotax fluid, the atf fluid as you've advised and then regular engine oil. Also, have you ever had any issues with oil spewing out the vent when filling with 100cc'? I've heard 50ccs prevents this and provide adequate lubrication

[@PowerRepublic]

Thanks for the great questions. I use ATF as is light and works perfectly. It is also easy to find at any Auto store. You can use the Rotax genuine Gear oil too, its awesome. For the DD2 I generally use the Rotax Gear Oil.

[@PowerRepublic]

Hey Chris, yes sometimes. You can run less oil without any negative issues, probably 80cc is fine. The recommended amount from Rotax is 100cc though.

[@mugenmrx5]

That's great info thanks so much for the reply. I guess the thinner ATF oil can potentially add a little bit of power especially for the ROTAX Micro/Mini categories.

[@mickgee6635]

Be careful ATF has been known to react with the plastic gears and the crank seals. You will find that engine had less oil because it was sucked into the engine via the crank seal.

[@dylanhallracing123]

Hey Dez, my kart only had 60ml of gearbox oil in it when I drained it, will this have caused any damage? Thanks and keep up the good work!

[@PowerRepublic]

Not the best but should be sweet. Top it up and keep an eye on it this time. Maybe check it twice as often as last time

[@mycorvettelife]

How often should you change the oil?

[@PowerRepublic]

every 3 meetings or if you go in the rain

[@teamgrimaracing3607]

How mate love your videos and also from Sydney, Australia. With The rotary engines what should you do to the engine like after every race meeting to keep it fresh.

[@PowerRepublic]

Thanks for positive vibes! are you asking about the 100cc air cooled rotary engines?

[@teamgrimaracing3607]

Power Republic omg I am so sorry I meant rotax engine bloody autocorrect. But any way my engine is a 125 rotax eve restricted.

[@PowerRepublic]

Oh sweet as@@teamgrimaracing3607 , after each weekend I would drain the carby and clean it out with some solvent and compressed air (there is a video on that). Every rebuild I would get the Needle and Seat changed and the fuel line, filter and fuel pump kit too. Also the clutch drum and the clutch bearing can do with a clean and re-lube. and clean your chain and check the front sprocket for wear. Other than that your engine should run for about 15-20 hours in restricted no problems

[@cagninadesign]

When you install the Gear Case Gasket, do you use any sealant or oil on it? or just place a dry gasket in between the aluminum parts?

[@PowerRepublic]

Hi Franco, if you want the gasket to come off easy you can add some oil to both surfaces (DD2 gear cover) On the senior max, because the cover doesn't normally come off between services, you can put it on dry.

[@cagninadesign]

Power Republic thank you man :) Your videos are amazing!

[@BK-it6te]

Does the DD2 takes the same amount of gear oil ? What oil would you recommend?

[@PowerRepublic]

Dd2 is 150ml and you can use atf or motorbike gear oils are better and stronger

[@soccerman4473]

Hello Mate just had a quick question, where can I buy one of those breathers that you have on the gearbox fill plug ? Thanks Tom

[@PowerRepublic]

kartshop.com/shop/new-line-overflow-29209p.html

[@ohhferno]

I couldn't help but notice the extremely large wedge under the engine, what benefits does that wedge give? Whether its an angle wedge or just a flat wedge would they give off a different power benefits? What would be a recommended wedge height?

[@PowerRepublic]

Hi Garrett, it's the top part of a 2 part engine slide mount system from DPE Kart Technology here in Australia. Check them out here www.dpekartsuperstore.com/kartech-engine-mount-slide-type-complete-with-bottom-top-clamps-bolts.html

[@Nickael7]

@@PowerRepublic On another subject, can we use these engines other than just go-karts ? Example: On-road Drift-Trikes and off-road drift-Trikes (with a jackshaft for speed reduction in the offroad scenario). I ask this question, because of the potential T.A.G. and powerband capabilities of the IAME and Rotax engines. The 4 stroke engines are way too big and cumbersome and the electrical motors with their batteries juice drops very quickly, I hate that ! And question number 2, can these engines be use for longer hours, since we aren't using them for competitions in this scenario ?

[@huntingtonhayes]

How often do you normally change the gearbox oil? Do you have a rough number of hours you recommend?

[@PowerRepublic]

I think that 6 hours use s fine or if you have been in the wet race. some guys wait until I rebuild the top end to do theirs, but I think every 6 to be safe.

[@ot77racing27]

Hello Des. I see you, and some others are using ATF instead of SAE30 oil in the box. Does using ATF give less ‘stiction’ on the gears giving a little bit of a benefit to the engine spinning up?

[@mike_kokuz17]

Love your videos mate, given me the confidence to work on my own engine. On top of the regular oil changes, how often would you service the gearbox as in the video?

[@PowerRepublic]

After the wet practise or after 10 hours

[@WeeDanHD]

Do you have to take the engine out of the kart to do this procedure?

[@PowerRepublic]

not really but it does make it heaps easier

[@user-ke2hw2nr8j]

How much oil i sholud put when changing it ? 100ml (as written on sticker) or 60ml ? Motor Rotax Max Junuor Evo. Changing thru the lower screw hole, not disassembling whole cover.

[@PowerRepublic]

100ml is Rotax recommended

[@trentashman9183]

How often do you recommend that you need to change the gearbox oil?

[@PowerRepublic]

Hi Trent, great question. Most of our customers leave until the next rebuild. So 15-20 hours worth of use. Now that you know how to do it yourself you can do it once a month or as often as you like. Maybe combine it with your clutch service as it in much easier to do both jobs on the work bench instead of the kart.

[@IggySport1388]

@@PowerRepublic cutting in here please excuse me, derek is that 15-20 your recommended top end service? If it is then how often do you do full rebuild?

[@PowerRepublic]

Christopher Ramnauth that’s right my friend. And every second piston do the bottom end as well (30-40hours). Other people have gone longer but some fail with unfavourable results

[@olisutton1368]

What's the thing attached to the breather? Do I need one?

[@PowerRepublic]

Hi Oli, great question, its a fuel filter. No you don't "need" one, but you can use it if you like. otherwise get a piece of go kart fuel line and just bend it up 180 degrees and stick the tail down between the cylinder and the crankcase.

[@charliepedersen1900]

This might be a stupid question but I'm brand new to the world of karting so bear with me. Is the Oil change the same on a rotax 125 dd2 engine?

[@PowerRepublic]

Charlie Pedersen hey mate, nah they are different. I use the genuine DD2 oil that is a gear oil and 150ml

[@luccaspenceley2366]

life saver :)

[@PowerRepublic]

Thanks Lucca

[@jwatch01]

When do you need to service the gearbox?

[@PowerRepublic]

every 10 hours or when you have been in the rain

[@rickyhutchings2263]

Hi great video, is it essential to run 100mm of oil ive heard rumours of people running half that .im torn between.

[@PowerRepublic]

you can run less, but how much is debatable. if you are about to win the world title and it hinged on less oil, do it. otherwise top it up to the 100ml and send it.

[@rickyhutchings2263]

@@PowerRepublic lol i dont think we are on that level yet ,it was just in conversation with someone who is racing i was just curious to ask.thanks for the reply great videos by the way👍👍

[@PowerRepublic]

@@rickyhutchings2263 anytime 😊

[@michaelfoey2358]

That's a good question - I put 100ml in my son's kart, but when we started his kart quite a bit of oil spewed out of the breather hole. Is that normal?

[@rickyhutchings2263]

@@michaelfoey2358 i think when i change it soon im gonna put 50mm and change it regularly.

[@jamesc5993]

Is the oil change process the same in a pre-evo?

[@PowerRepublic]

sure is, the only difference was for the pre 2009 rotax engines with the plastic balance gears if they are still in service

[@paudinares7054]

can I use 75W-90?

[@PowerRepublic]

Yes you can. But it’s heavier than ATF

[@paudinares7054]

@@PowerRepublic So it's better for hot weather or what's the deal?

[@juliojtrkarting]

😎😎😎

[@PowerRepublic]

Thanks

[@mathewandersson2102]

Why is it saying 100cc on the moter, but 125cc in the titel? Sorry if it is a stupid question but it would be very Nice if you Answer so i know😃

[@PowerRepublic]

Mathui Andersson great question. The name of the engine is a Rotax 125cc (Engine capacity) with only 100cc oil capacity for the gearbox. (the sticker you see on the gearbox cover). Hope that helps

[@martijngeven4898]

The engine needs 100cc of oil in the gearbox. the engine capacity is a 125 cc 2stroke engine. A suzuki needs 5 liters of motoroil but doesn't have a 5 liter engine. Greets Martijn, Germany

[@ayfzshstz9563]

Here a dot there a dot everywhere a dot dot, Rotax Evo has a dot, e, i, e, i, o.

[@PowerRepublic]

dot everywhere

[@JuanGonzalez-oo6hf]

So when aligning the gears, will it give you more speed and power on the long road?

[@PowerRepublic]

No it’s for harmonic balance of the 125cc engine

[@Solislegend]

Does this guide include the Rotax DD2 Engine?

[@PowerRepublic]

no but it almost the same method except that you need 150ml of gearbox oil

[@oscarchristensen294]

When you buy a brand new Rotax engine, does it come with all the oils and stuff?

[@PowerRepublic]

No too oil. Come with all the engine parts like exhaust, radiator, wiring etc etc

[@oscarchristensen294]

@@PowerRepublic i mean example gearbox oil.

[@PowerRepublic]

@@oscarchristensen294 yeah nah just get some ATF and go your hardest

[@oscarchristensen294]

@@PowerRepublic whats ATF?

[@tamexm8638]

@@oscarchristensen294 Automatic Transmission Fluid