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Jan 20, 2020, 03:27 PM
Registered User
Thread OP
Thx Hansen, I woke up today determined to knock it out, I managed to get a flat screw driver under the inner race, which is loose as hell, and gave it a few smacks 90 degrees apart, few more case smacks on the wood and out it came....Now clean up and BB time...so much fun...so far.
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Jan 20, 2020, 03:35 PM
GloBroz PowerLab
1QwkSport2.5r's Avatar
Quote:
Originally Posted by Pylonracr
Getting that Jett to idle below 1800 would be tough... I never put a tach to the idle so I don't know for sure. My best possibility is my Novarosse R61 Speed13. With a carbon 8.9 x 10.25 prop it will turn 20,500. I never checked the idle, but if it will idle below 2K it would qualify. Next time I run that engine I will check the idle.

Scott
My .56 will idle down to 1600rpm and it’s peaking over 18,500rpm with the pipe I have. My .35 is tighter than the .56 and as such wont idle down below 1800rpm yet. I think my best examples with low idles are my K&B Sportsters. The .65s will idle down to about 1400rpm or better with a 13x6, but they’re low rpm engines and as such don’t like to peak above 12k. I have a video of my .65 in slow motion and it’s interesting to hear it running - at sub-2000rpm idle speed, it only fires every third revolution or so.
Jan 20, 2020, 03:35 PM
AMA 46133
SeismicCWave's Avatar

Bearing puller tutorial....


Seems like this has been a topic that has been asked a lot. So I did a bit of thinking and here is what I come up with. I can make some tools with my lathe and other machines but let's say some other hobbyists with limited tools.

So I did this just now with basic hand tools.

I am going to load the pictures but I am not sure which order the pictures will appear in the post. So I start with the finish product first.

1) Start with a need....that will be a stuck bearing inside a crank case that won't come out.
2) Find a suitable item to make a tool......this one I am using a carriage bolt with the head just a little bigger than the ID of the bearing in question.
3) I put the head of the carriage bolt to the bench grinder. I can also use my lathe or the belt sander. I imagine some one can actually use a hand file but it will take longer. Grind the edge of the bolt head sharp and the diameter just fit through the ID of the bearing snuggly.
4) Put the carriage bolt on a vice and start a slit with a Dremel disc (#409 abrasive disc).
5) Then I put a hacksaw on the slit to cut it deeper. If you use a hand operator hacksaw it will take a little while depending on the sharpness of your blade.
6) Cut the slit 1" to 1.5" deep.
7) The idea is to be able to wedge a flat blade screw driver in the slit.
8) Push the carriage bolt into the bearing. If it is loose just take it out and wedge the slit a little with the screw driver. You want some friction.
9) Push until you can feel the small area between the end of the bearing ID and the start of the crank case.
10) Turn the engine so the carriage bolt is against something solid.
11) Hammer the end of the screw driver until the carriage bolt head is spreading against the area between the ID of the bearing and the crank case snuggly.
12) Take the whole thing and put it on a vice or some thing solid.
13) Apply some heat to the crank case and tap with the hammer.
14) Voila, the bearing should pop out now.

Ok I just looked. Stupid old me. I loaded the pictures backwards. So you follow the picture from the last one first.
Jan 20, 2020, 03:37 PM
AMA 46133
SeismicCWave's Avatar
Quote:
Originally Posted by Sam Ehab
Thx Hansen, I woke up today determined to knock it out, I managed to get a flat screw driver under the inner race, which is loose as hell, and gave it a few smacks 90 degrees apart, few more case smacks on the wood and out it came....Now clean up and BB time...so much fun...so far.
That's good. I guess my tutorial may be beneficial for others as well. Maybe I will start a new thread to make it easier for some one to search for answers later on.
Jan 20, 2020, 03:42 PM
Still gassin' it.
Quote:
Originally Posted by 1QwkSport2.5r
My .56 will idle down to 1600rpm and it’s peaking over 18,500rpm with the pipe I have. My .35 is tighter than the .56 and as such wont idle down below 1800rpm yet. I think my best examples with low idles are my K&B Sportsters. The .65s will idle down to about 1400rpm or better with a 13x6, but they’re low rpm engines and as such don’t like to peak above 12k. I have a video of my .65 in slow motion and it’s interesting to hear it running - at sub-2000rpm idle speed, it only fires every third revolution or so.
vid or it didn't happen....
Jan 20, 2020, 03:54 PM
AMA 46133
SeismicCWave's Avatar
Quote:
Originally Posted by 1967Brutus
vid or it didn't happen....
I concur.
Jan 20, 2020, 04:24 PM
Scott
Pylonracr's Avatar
Tim, this will give you a good opportunity to test your Macs pipe against your new carbon fiber pipe....

Scott
Jan 20, 2020, 04:26 PM
Registered User
Thread OP
Great home made tool Hansen...Next time I'll make one up if needed.
The Rossi 40 parts are soaking in old 15% nitro fuel, brushing and re-brushing. Today MLK day I was planning to fly but weather is bad so I have some time to spend on a few engines that need TLC.
Jan 20, 2020, 04:47 PM
Scott
Pylonracr's Avatar
That is a right nice looking rear bearing you have there Sam. Good thing you planned on replacing it...

Scott
Jan 20, 2020, 05:02 PM
Still gassin' it.
Quote:
Originally Posted by Pylonracr
That is a right nice looking rear bearing you have there Sam. Good thing you planned on replacing it...

Scott
why? very "used but usable" as they would say in my workplace…
Jan 20, 2020, 06:07 PM
Registered User
Thread OP
Quote:
Originally Posted by Pylonracr
That is a right nice looking rear bearing you have there Sam. Good thing you planned on replacing it...

Scott
Yeah Scott, it fooled me, it felt really good, maybe due to hi compression in the piston/sleeve and a good front BB I didn't feel any play.

I was mistaken, no balls are missing but the inner race is too loose indicating massive run time or lack of lube, or both!

I think this engine was run a lot, then stored wrongly then cleaned on the outside and oiled before I got it. If I had run it, all the junk would have ended destroying the piston/sleeve.

I'm excited to get it running soon!
Jan 20, 2020, 06:19 PM
Still gassin' it.
Quote:
Originally Posted by Sam Ehab
the inner race is too loose indicating massive run time or lack of lube, or both!
Not necessarily: ball bearings have severely limited life expectancy in this application anyway. Front bearings, depending on starting method, starting manners and prop balance can last quite long, but main bearings usually don't last much beyond 200~400 hours, many times MUCH shorter (I have seen them letting go within 25 hours, on OS engines predominantly, they had several production runs equipped with bearings made out of Play-Doh).

But mind you, that's a bearing with a phenolic cage, best replace with one like that as well.
Jan 20, 2020, 06:27 PM
Registered User
Thread OP
Do you guys recommend fully sealed? half? no seal?
I think I should have at least the front half sealed (front) in case the shaft doesn't seal agaisnt the case due to corrosion/pitting.
Jan 20, 2020, 06:37 PM
Scott
Pylonracr's Avatar
I typically run no seals on either bearing. I have seen some (taken engines apart) with one front seal.

Scott
Jan 20, 2020, 06:43 PM
AMA 46133
SeismicCWave's Avatar
Quote:
Originally Posted by Sam Ehab
Do you guys recommend fully sealed? half? no seal?
I think I should have at least the front half sealed (front) in case the shaft doesn't seal agaisnt the case due to corrosion/pitting.
Definitely no seal nor shield on the rear bearing. The front bearing will depend on the engine. If the crankshaft to crank case fit is loose from rust and wear then you need seals for the front bearing or you will be spitting raw fuel. I have had Rossi's spitting raw fuel. I had to resort to the black rubber seal for front and back of the front bearing to slow it down. My rebuilt YS 61 is the same way. Also an old OS I rebuilt. So far I see there are two types of seals. The blue more plastic feeling seals and the black more like rubber type seal. The black rubber ones have a bit more friction but seal much better.

I have had engines that I changed front bearings three times just because fuel is spitting out the front.

If you ever take apart a YS 91 four stroke you will see a pretty elaborate rubber seal right behind the front bearing.


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