Rotax 787 RFI Rebuild

Rotax 787 RFI Rebuild - Part 1

Рет қаралды 13,420

2 жыл бұрын

Welcome to part 1 of the Rotax 787 RFI Rebuild. In this first episode of this series i install the new crankshaft, install the rotary valve shaft, time the balance shaft, and join the cases.
For more awesome 2 Stroke videos check out my Rotax 951 Rebuild Series!
• Rotax 951 Rebuild
Patreon link
/ kolederacer
Favorite Engine Clearing Supplies
Gunk Gel - amzn.to/3nyeauD
Gunk Original - amzn.to/3tDfFsm
Gunk Orange - amzn.to/3C2Kee6
Simple Green - amzn.to/3tBgHFz
Music
www.epidemicsound.com/

Пікірлер: 35

@andrewcalk878 2 жыл бұрын

Hey , isn’t there an o-ring that goes on the pto end of crankshaft before the main seal?

@DeWoodysShop 2 жыл бұрын

Yes there is sorry did not film it or mention it specifically.

@JOSERGMMXX 8 ай бұрын

having that issue right now air leak by pto area cause didnt put that o- ring i guess

@andrewcalk878 8 ай бұрын

@@JOSERGMMXX oh yeah dude..same with another big channel “todaywewrench” both of them forgot a critical part..useless

@freelectron2029 5 ай бұрын

everyone wants to go make a video "showing you how to do it" but doesnt know what they are doing themselves then doesnt take responsibility for spreading false info. really annoying.

@andrewcalk878 5 ай бұрын

@@freelectron2029 really frustrating

@ansissvars3523 Ай бұрын

Good video. But why you do not whant to show deetails. Like balanser shaft, timing point have 2 teath diapason.

@ansissvars3523 Ай бұрын

Or precision in ther is not so important?

@JOSERGMMXX 6 ай бұрын

i purchase a crankshaft from ebay brand wsm looks like the one you install gold color center seal in the center , cause old cranksfhaft are red color anyways is been 3 times already replacing the rotary valve shaft cause keep damage the brass gear ,only last 5 min running and goes bad so i decide to split motor again and check diameter of both middle gear crankshaft and are not the same old crankshaft is little bit not much but is bigger of the wsm brand do you think this may be the issue of keep the damaged the brass gear maybe is not completly grabing the tooth of the brass gear

@kyletaylor6935 2 жыл бұрын

When you were putting the sealant on the case halves, what was the little bolt you were using on the tube to help squeeze the sealant out? That looks very cleaver and convenient

@DeWoodysShop 2 жыл бұрын

Its like a hollow little tube winder thing. It came with the yamabond in the package. It is really useful for sure.

@flyingkevo 19 күн бұрын

how much did it cost you to rebuild it yourself?

@ripptydevibes2581 Жыл бұрын

I installed a brand new SBT 787 carb engine, on my oil deleted jet jon boat. Unfortunately when I filled my oil loop (rotary valve bath) there must have been an airlock bubble. Luckily in the first 3 minutes of light throttle on the water, I saw that the oil loop ran dry on one side, not the other. Immediately halted the mission and came back t the shop and ended up putting in again as much oil as originally. So, the valve bath was HALF full of oil on a brief run. Do you know the internal design of these blocks well enough, was half full enough oil for the crank to sling around and keep everything wet? Or do you think we need to pull and inspect anytihng? My full time mechanic career tells me everything should still be fine but these seadoos are not yet fully understood in my mind!

@DeWoodysShop Жыл бұрын

It should be fine if you are talking about the internal bevel drive inside the block. Normally the oil is "pumped" through there, I think its the bevel gear itself moving the oil through there. But its all ball bearings and just a gear so long as a reasonable amount of oil was already in it i would not be worried. The disk itself is the sensitive thing in the system that can quickly get ruined. But if you are a running pre-mix should not be an issue for you.

@martinkx250f 2 жыл бұрын

I see you bolted the cylinders to the upper half of the case pretty quickly before flipping it up! Is it a mandatory step or is it also possible to first close the crankcase and then assemble the cylinders? Thanks

@DeWoodysShop 2 жыл бұрын

Its not, I mentioned it was just sitting on it for somewhere for the rods to go while I assembled it.

@grast5150 Жыл бұрын

Question, Should you not use 515 or 525 gasket maker on the crank shaft seals?

@DeWoodysShop Жыл бұрын

Rotax does not call for it, There should be no need for that on good modern case that fit and seal correctly. There is gasket maker on the edges but if you mean putting it all the way around the seal no.

@genetemplet7022 Жыл бұрын

I agree 100%. I was told nothing was needed on the inner lip seals when I did my first engine. Now I have a "shut off" valve on the rotary valve feed line because it leaks internally. LOL Second engine I tried moto seal on the inner lip seals but didn't like it as it set up too fast. I use 518 as it is anerobic and won't get hard till oxygen is removed. I will not assemble an engine without something on those inner lip seals. I also use a very light coat of sealant on the outer edges of all the lip seals and end caps but not Motor Seal. :D

@jasongrenon9129 2 жыл бұрын

Any tips on getting the motor out of the 3D? About to embark on this journey at the end of the season

@DeWoodysShop 2 жыл бұрын

Its really not bad as far as skis go. I think I took the pipe and throttle bodies off if I remembered right

@saracondon7115 Жыл бұрын

I bought a 3D with the same problem, were you able to buy the complete crank assembly ready to install?

@DeWoodysShop Жыл бұрын

Yes just bought a rebuilt crank from sbt I believe. Has all the bearing and seals on.

@bradleycarroll5038 Жыл бұрын

where do you recommend to order parts from ? thanks great vids

@DeWoodysShop Жыл бұрын

Partzilla.com or my local deal since they price match and give me a discount.

@jeanpaulrodriguez3367 2 жыл бұрын

What type of oil are you using in the red tank

@DeWoodysShop 2 жыл бұрын

Its two stroke oil. I think pre-mix Yamaha "yamalube"

@papadonjetski9535 2 жыл бұрын

Who did you purchase the crankshaft from?

@DeWoodysShop 2 жыл бұрын

Its a WSM rebuild kit.

@rashpaldhaliwal1713 Жыл бұрын

You have 787 Or you can rebuild for me Where are you Your video is really good

@DeWoodysShop Жыл бұрын

Only the one in the 3D. I am in north east Texas.

@shannonwilliams601 2 жыл бұрын

The sky made a huge mistake I have been building two-stroke jet skis for over 20 years he did not put any sealer between the two case halves it's very important and you also put it around the edge of the main seals otherwise you will have a pressure leak eventually these engines are so old you're not dealing with totally flat surfaces anymore this is a big No-No

@DeWoodysShop 2 жыл бұрын

If you refer to this video between 6:50 and 8:40, I spend almost two minuets putting case sealant on and talking about it.🧐

@genetemplet7022 Жыл бұрын

Yup, ALWAYS put something on the outside of the lip seals. No leaks.

@tg5509 Күн бұрын

He did. Thanks for the video man!