Thank you for making this excellent video. I've been putting off my reduction drive rebuild for a while as there were no warning signs of failure. At 300 hours however, I saw some metal flakes in the oil and knew the time for rebuilding had arrived. Turns out my drive was eating ball bearings like they were PEZ and upon splitting open the drive, the faulty bearing fell completely apart. I found your rebuild video easy to follow and preferable to the approach that the Vittorazi manual describes. I really appreciate your time.
I used a titanium bit that came in a set from Harbor Freight. Those rivets are stainless steel so they’re pretty thought to drill out and require a heavy duty rivet gun to replace.
@@white7684 the shank of the rivets are 3/16”. So that would be a good drill bit size to start with. Also, using a punch to drive out the pin in the center of the rivet (the mandrel) after drilling the head a bit, will sometimes be enough to break the rivet loose.
Hi Dennis, great video with a lot of details.. I have a MY20 that needs a rebuild but its a bit beyond my skills,, so do you build for a fee for others??
Thanks for the kind words. I have rebuilt one or two for other pilots. Usually they’re local though to avoid the shipping costs. Are you on Facebook? If so, we could exchange phone numbers and discuss options on getting yours fixed up.
Havasu was pretty good. The footage in this video was from our trip to Glamis in January. Needless to say, I’m slow at getting these videos processed. 😂 This one took 10 months.
I like your work. But I feel that it will be impossible to do the work you do, with the tools we have normally at home. Nevertheless I am thinking if the mechanics that work on our gear will do the job as nice and carefully as you are doing it. Thank you for all your wonderful videos. They are the bes!
Yeah, the gearbox rebuild does require a decent amount of mechanical know how. I’ve rebuild a few since making this video and a lot of the disassembly can be made simply by heating up the cases and then the bearings will simply fall out. But it is pretty involved. If you’re in the USA, I do know that skysportsusa does do this type of repair if you ever needed it.
Where I live , we don´t have mechanics in paramotor engines; to whom do you think I should ask for advice? A motorbike mechanic maybe? A karting mechanic? At least to make the normal maintenance of the engines...
Yes. Both karting and motorbike mechanics would be good choices if they’re familiar with two stroke engines. Even some lawnmower/landscaping mechanics have the ability also.
This is the best video for ATOM 80 owners. It is my favourite ! Thank you so much for your excelent work and images. Now I want more! Would you please show us the electric system and replacement?
Thanks for the kind words Martin. This video does show removal and installation of the coil and flywheel. Other than that it’s really just the kill switch on the throttle. But the throttle would be different for every frame manufacture. But let me know exactly what you’re looking for and maybe I can make a video.
Yeah. I ended up buying another pull starter so that I’d have a spare on hand. Now I simply rotate the two in and out whenever I have the engine off or need to swap pull starters. This enables me to have somebody hold the engine in place for a minute while I swap pull starters. I don’t have to disconnect all the wiring, fuel lines, etc. Then I clean and inspect the dirty one and keep that as my backup.
Thanks for the kind words Thad. Keep in mind that I made this video a long time before Vittorazi came out with a service manual. This technique though has served me well. When I made this video, I asked Vittorazi how to wrap the packing and which way the inner mesh was oriented. They sent me the picture with the description of the orientation being “towards the final chrome”. So I put it in as per the video. But their maintenance manual, starting on page 36, shows it the opposite. 🤷🏼♂️ vittorazi.com/manuali/Maintenance_manual_Atom80_Eng_022.pdf?fbclid=IwAR3Q-giff3-l5xb9oVDGjdLas3HvJzciFITj2-omuz2YC-93aW-U9LPxfHM Personally, I like having the extra packing towards the baffle because there tends to be a lot of heat concentrating in that area and burning the silicone causing a heat signature on the outside of the exhaust. Also, one technique that I have used since this video is to use an old exhaust bracket (or make one out of flat stock) to secure the exhaust in a vice. Don’t put the vice to any parts of the exhaust that will be used during flight. But holding it in a vice will make it much easier to disassemble.
It should be fine if you pierce the plug wire in it’s center. However, you could still verify contact by running a continuity check between the copper wire and the spring/plug connector.
I’ve rebuilt a few Atom80 gearboxes since I made this video. The newer gearboxes are much easier to split the cases making the job much easier. I’ve also found that heating the the bearings will simply fall out by heating the case halves to the correct temp, no need for special tools. But I’d only heat them if you’re planning on replacing the seals too. Check out this video for the update on splitting the cases. Good luck with the rebuild, let me know if you have any questions. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Ht8ENpR8htA.html
This was a great video, thank you so much for making it. I watched it at least three times while doing my 200 hour maintenance which according to the manual requires all of these steps. That said, my engine looked great and much of the work was possibly unnecessary. I especially appreciated your approach to freezing the crankshaft and heating the crankcase beyond what the Vittorazi manual suggested as that worked great. The solder trick for the clearance measurement was fantastic as well. Again many thanks for the "virtual hand-holding" while I did this work.
Thanks so much David for the nice comments. It took a lot of time to make this video so I’m glad to hear that you found it useful. Hope to see you in the air!!
You’re welcome Dan. I like working on engines, so I think filming and editing this was tougher for me than the actual engine teardown and rebuild. I’m happy to see and hear that others are benefiting from it too. That makes the work worth it in the end. Thanks for the kind words.
If you’re not already aware, this video is an update to a prior complete rebuild video found here. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_mFpdoJdeq8.html Best of luck with your rebuild. Let me know if you have any questions or need help along the way.
Thank you for making this video! My clutch plate just failed yesterday. Do you know if the new, thicker plate fits in place? Should I get the whole assembly instead?
Hey Victor. I pulled out one of my older clutches and compared it to a new one with the thicker backing plate. It does appear that all of the parts on the old one will bolt straight onto the new backing plate. However, I did notice that the new shoes have a slight difference in where it contacts the backing plate at rest. There’s a small nipple on the newer clutch shoes so the contact point is much smaller. Personally, I got about 460 hours out of my original clutch before it started to slip a little bit under high rpm’s and only 165 hours before my last one broke. I hate missing flights, so I’d just replace the entire clutch if you feel like you’ve put a lot of hours on the shoes anyway. Best of luck on the decision. Feel free to reach out if you need any help swapping it out.
I don’t know, I’ve seen better. 😂 But, Thanks for the kind words Bill. I enjoy working on engines. That part comes easy for me. The video part was a lot of work making this one. I’m just happy that other people found any of it useful.
My unit has about 200 hours. I used your video to do that part of the 100 hr. top end rebuild. My cord looked fine, but was replaced since it came in the kit. Most of your video was fine. However you made it look toooo easy placing the clips in the head! I wish you had included how the rope is attached to the pull start wheel. I guess I should have figured it out, but didn't. Now I have an issue that is baffling me. After reinstalling everything, the pull cord now comes over my left shoulder, whereas before it was over my right. And the place to attach the pulley is on the right side of the two 'v' tubular struts from the frame to the cage.
Hey Don. I didn’t replace the cord on this rebuild so I didn’t have any footage on replacing the cord. As far as why the cord is pulling over the left shoulder. All I can think of is that you might’ve installed it 90 degrees off. Maybe take a look and make sure that the outlet for the pull cord is facing upward on the carb side of the engine. Hope that helps.
Jeez dude just watched it again your cases looked BLACK and real nasty inside haha. My large gear stayed on the other case cover so i have to make a tool using a slide hammer to get it off tommorow. Everything is going smooth i did bugger up the original case threads slightly on the top jacking the cover up(MY19)I was not in the mood to make a plate lol.I just ran a tap through them and filed the case flat again.The drive side of both my gears are hammered and 2 of the bearings are grumbling.One on the outer side of small gear and one on the outer prop hub shaft.
Yeah. The little bearings take a beating in there. The slide hammer will work. Another option is to heat the case up a bit with a heat gun or a few minutes in an oven and the cases will expand and the bearings will simply drop out. Same in reverse, heat the cases and freeze the bearings and the bearings will simply drop in. Anyway, keep at it. Glad to hear that you’re getting it done. 👍🏽
@@wednesdaykartingflyingclub8164 Dude Im just waiting for my parts now its all apart. I have two more questions.1.Can all the bearings go in anyway or do the letters always go down.I noticed on one of the gear bearings(larger one with less balls)there are no markings.2.Would it be better to stick the cases back in the oven with the new bearings in them and heat them up before tapping cold gears into cold bearings.Especially when we have to beat on the INNER race to instal which is the weakest part of the bearing?
@@577buttfan I haven’t personally paid any attention to the direction of the bearings. I did notice on the engine main case bearings that Vittorazi does now have a recommendation for bearing direction on those. But not on the gearbox. The easiest way to assemble would actually be to heat the bearings and cool the gears. Then assemble the bearings onto the gears (they should slide right on). Then heat the clutch side case, cool the bearings (with gears now attached) and drop the gears into the clutch side case (might take a slight tap with a block of wood and a mallet). Next, install the Oring, case seal and clutch drum which will finish that side. Then, I’d cool that entire assembly and heat the prop side case. The prop side case should then fit onto the gears with a slight tap of a mallet and block of wood. Then don’t forget to put the thin oring, case seal, prop bushing then finally the prop hub back on. That’s the order of how I’d do it now after a few rebuilds. Check out Vittorazi’s manual. They now break it down too. vittorazi.com/manuali/Maintenance_manual_Atom80_Eng_022.pdf?fbclid=IwAR3Q-giff3-l5xb9oVDGjdLas3HvJzciFITj2-omuz2YC-93aW-U9LPxfHM Also, I’ve found that replacing the bearings will eliminate the grinding noise of the gearbox (provided that there’s no major damage to the gears). But the only way to get rid of the high pitched whine during high rpm’s (if yours is making that noise) is by replacing the gears too. So, if you’re replacing the gears, make sure with your parts supplier that they send a main gear with a psi relief valve built in, or order one to be installed when you get it.
@@wednesdaykartingflyingclub8164 Yeah mine had that high pitched whine and I ordered both gears and all 4 bearings.Not sure if the gear is going to be updated with PSi relief I hope so. Thanks again man!!
@@wednesdaykartingflyingclub8164 Mine has been developing a high pitched whine but it started really slow and would only make the noise for 2-3 seconds on and 2-3 off.Now its louder and more constant plus if I spin the prop CCW it grumbles pretty good. How exactly did you split the cases.I dont understand how putting bolts back in there will jack the covers apart? Thats the only step thats confusing me so far lol :)
@@577buttfan what year is your gearbox? The my20 and newer ones have two threaded spots in the case cover to split the case. However, all model year outer covers have oversized threads on the case cover. There’s a link in the description to an update to this video with pics of a better way to split the case. Hope it makes sense.
@@577buttfan Look at this video before rebuilding. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-2CnCr7I9oes.html After rebuilding a handful of these I’ve realized that it’s better to “lift” the lid of the gearbox (when splitting the case) rather than “jack” it up as shown in this video. This can be accomplished by using a flat plate over the output shaft gear with holes that correspond to the lid retaining bolt holes. Then using bolts to reach through the plate in order to lift the lid.
I really appreciate the step by step video. I have yet to try and get a manual for this motor, but would be interested to hear which pullers you used in your rebuild.
Here’s a link to Vittorazi’s maintenance manual. I made this video about a year before the manual was published. So keep that in mind. I did buy all my parts along with a flywheel and multi (prop hub/ clutch) puller from www.skysportsusa.net. The other pullers/case splitters I made using flat stock aluminum and correctly sized bolts. vittorazi.com/manuali/Maintenance_manual_Atom80_Eng_022.pdf?fbclid=IwAR3Q-giff3-l5xb9oVDGjdLas3HvJzciFITj2-omuz2YC-93aW-U9LPxfHM
Glad that you found the video of some use. For a MY20 or newer model Vittorazi calls for 10Nm for the drain and fill plugs and 3Nm for the check window bolt. Based on those numbers (and since there’s no service manual from Vittorazi for the older design) I’d go with 10Nm for a fill plug and 3Nm for the drain plug on a MY18 or MY19 gearbox. I hope that makes sense.
My guess would be the clutch shoes clanging on the clutch drum. If it is, it’s common with this style of clutch. The engine that my instructor had in training did that. Your engine might be set so that the rpm’s are set right at the point that the clutch engages while at idle. It’s possible that simply dropping the rpm’s will prevent the centrifugal clutch from engaging/disengaging. It’s also possible that a clutch spring is broken. But I haven’t heard of that on an Atom80.
@@wednesdaykartingflyingclub8164 Yeah I hear the bell dinging once in a while but there is also a clacking. I'll have to open her up and take a peek. Thanks for the help dude your the man!!
You’re right, this is without question the simplest way, requiring less tools, to get the job done on a MY18 or MY19 gearbox. This is only one way to get the job done. In fact I’ve used this and one other method where I used a plate to lift the outer case rather than “jack” it up with bolts. (See the video description for a follow up link to this video). Also, the MY20 gearbox does have two threaded holes on the case cover specifically designed to jack it up. Jacking the cover up there would reduce the risk of destroying any threads in the lower case.
Check out Vittorazi’s website for their new maintenance manual. It shows in great detail the breakdown of the gearbox as well using the MY20 or newer gearbox and the two jacking bolts. vittorazi.com/manuali/Maintenance_manual_Atom80_Eng_022.pdf?fbclid=IwAR3Q-giff3-l5xb9oVDGjdLas3HvJzciFITj2-omuz2YC-93aW-U9LPxfHM
