Laser 180 bearing replacement

[Tim Flyer]

I decided to replace the bearings on one of my 180s today after feeling a small bit of sideways play on the prop and hub during my last flying session. It was small and only like a slight movement when applying side force to the propeller tips. There was no noise but I have learned it’s definitely best to replace once an issue is spotted before any damage can be done. 
 

This engine is side mounted in my Acrowot. and has seen a fair bit of use and is about 3years old. It hasn’t been used much this year though. The  engine is side mounted and due to easy fuel pipe/carb access I can easily remove the fuel supply whilst it is still running at the end of a session so corrosion shouldn’t be much of an issue. 
 

I found the bearings to be reasonably smooth although slightly gummy and possibly at the early corrosion phase. 
I decided to replace both as the fuss of pulling the engine apart isn’t worth it for just one bearing and the SKF bearings j bought from Simply Bearings are only about £5 each. 
 

 

The job was fairly simple using a bearing puller to remove the drive hub . Knocking the old bearings out required care as they  were very tight.  I used a large vice and hammering bolts as drifts and some heat and penetrating oil. I managed to save the front housing o ring which I carefully removed before extracting, and heated the front housing with a heat gun.  
I left the engine in the plane and just took the front end off. When remounting the front end I carefully spread a fine layer of thin silicone on the crankcase joint to help it  seal.
 

One thing I noticed about the old front bearing was that some of the original grease remained although in a sticky state. Maybe occasionally removing the drive hub and seal and lubing front bearings would extend their life? The rear bearing does not use any seals so is better bathed in oil . The 180 bearing sizes are front 6201 2rs with a seal removed on the inside of the front bearing, and 6202 rear. 

Edited August 6 by Tim Flyer

[Paul De Tourtoulon]

Only 3 years running 🤢maybe you should try another mixture of fuel, most of my 4 strokes only needed replacement bearings after 10/15 years of running,

 my Enya .90,4c needed them after 20 years,.

[Andy Stephenson]

As far as I can remember, Lasers have a 3rd bearing at the back end of the crank that supports the drive for the timing pinion. It may be worth looking into this but if you do, you will need to make sure the valve timing is correct when you reassemble it.

[Learner]

9 minutes ago, Paul De Tourtoulon said:

Only 3 years running 🤢maybe you should try another mixture of fuel, most of my 4 strokes only needed replacement bearings after 10/15 years of running,

 my Enya .90,4c needed them after 20 years,.

What do you suggest Paul?😉

[Tim Flyer]

Thanks Andy yes they do have a rear bearing for the pinion which is a 608 but I think that’s still perfect . 

[Paul De Tourtoulon]

1 hour ago, Learner said:

What do you suggest Paul?😉

I use Castor oil, a minimum of 2%, you will get 1.000 reply's not to, as modern oils, black exhausts, gummed up motors blablabla etc,,,

Or you can use an after run, another 10 recipes.

LaserPDF.pdf

[Don Fry]

Errrr, our engines have very little use, I’ve got a 40 year old laser 75, had it for 25 years. Estimate, I’ve done 250 hours. The first owner did a lot of hours, a couple of hundred? The second owner messed with it, and tried to run it with the timing out. I bought it as scrap. Back then, I used to use a Southern modelcraft fuel, with some castor in it. It ran fine. For the last 18 years, it run on all synthetic fuel, nowt special, what’s to hand, less gunge, but otherwise no change. Caster does not destroy engines, but castor is a 100 year old technology, not needed.

Rust destroys engines. Lot of hard high carbon steel in them. As in swords, knights used to grease them, and they didn’t use methanol. Also less painful as you got disemboweled, but that’s off post. 
Run them hot, and burn the fuel off, to store, use after run oil if you want, no harm done after emerging from the smoke, dramatically, after it starts again.

Edited August 6 by Don Fry

[Engine Doctor]

As Don says rust destroys engines/ bearings. Poor storage or running can make things worse. Never run a fs rich as you only want un burnt oil in the crank case not methanol. Also last flight of the day while engine is good and hot empty tank and run it dry.

You shouldnt need yo drift out bearings as this can damage the case etc. Just heat the caae and they will almost fall out. Similarly re-fitting heat case and keep bearings cold and thry will just slde in without any knocking needed.

Some of us disagree on this but I will never use castor oil in a modern engine. Castor oil is ftom a bygone age . M9dern engines produce a lot more power than tge oldies and that means a lot more heat. When castor gets too hot it turns to varnish and that will damage a  engine. Modern synthetic oil is the way to go.

Edited August 7 by Engine Doctor

[Jon H]

21 hours ago, Paul De Tourtoulon said:

I use Castor oil, a minimum of 2%, you will get 1.000 reply's not to, as modern oils, black exhausts, gummed up motors blablabla etc,,,

Or you can use an after run, another 10 recipes.

LaserPDF.pdf 98.8 kB · 5 downloads

 

These instructions are obsolete and should be ignored. The Engine in question wasnt even in production at the time. The definitive version for laser instructions is from 2023 and covers all engines 1992-the end of production. 

 

After run used the way modellers do is a total waste of time and money. It is completely ineffective when it comes to rust prevention, particularly in a 4 stroke. 

 

Tim's bearings have gone rusty, and they are dead. The fuel is irrelevant as its rust that caused the damage. 

 

8 hours ago, Engine Doctor said:

You shouldnt need yo drift out bearings as this can damage the case etc. Just heat the caae and they will almost fall out. Similarly re-fitting heat case and keep bearings cold and thry will just slde in without any knocking needed

 

in this instance it will be fine. I pressed them in cold, and pressed them out cold. The fit is too tight for them to fall out just with heat. I had a bench press to aid the process when at the factory....i guess i will have to buy one for home use now i can no longer service my engines at work 

[Andy Stephenson]

Providing you only press on the race that is the tight fit then I can't see how you can do damage whilst fitting them. I'm sure they don't heat up every crankcase in the factory where they make them. It is damaging to press on the wrong race as the force across the bearing will indent the balls into the other race and leaving it running rough from new. Drifting them out on the other hand is not so much of a problem, providing they don't get skewed too much in the process.

[Paul De Tourtoulon]

Back from holiday jon ?

 

I also put it in the freezer for a few hours and like ED, a bit of heat on the aluminium casting, and they drop out, or drop in, if you don't use the right tool and use a press and put them back out of line you will do more damage than good.

 

 

Maybe next time I will try out stainless steel ones, but are they 18/12 rust free ?

[Martin Harris - Moderator]

2 hours ago, Andy Stephenson said:

I'm sure they don't heat up every crankcase in the factory where they make them.

I’m sure you’re right -Jon built all of the later Laser engines (and serviced any that were returned to the factory) so you can take what he says on this matter as gospel. 

[Engine Doctor]

15 hours ago, Andy Stephenson said:

Providing you only press on the race that is the tight fit then I can't see how you can do damage whilst fitting them. I'm sure they don't heat up every crankcase in the factory where they make them. It is damaging to press on the wrong race as the force across the bearing will indent the balls into the other race and leaving it running rough from new. Drifting them out on the other hand is not so much of a problem, providing they don't get skewed too much in the process.

Hi Andy . You are correct in what you say however how many folk have access to an accurate press and the parts needed to press bearings in squarely on the correct race?  Ive lost count of instances over the years where bearings have been pressed out of square on model engines and cars causing damage or pressed on the wrong race ruining the bearing. 

Jon says heat wont work but I have to dissagree . There isnt much we dissagree on but we have our ways and have to agree to dissagree. Ive rebuilt a number of Lasers and they are just like any other engine when it comes to removeing or fitting bearing using heat. Alloy expands more than steel and bearing become loose its just a fact.

[J D 8 - Moderator]

         Agree with ED above, a bit of heat and or cold will often make for an easy fit. 

         Another trick I use when fitting a new bearing [ not just model ones but larger stuff also] is to use the outer race of an old bearing to lightly drift new into place. Old race has a 1mm/1.5mm cut in it so is easy to remove again if it grips.

 

[Andy Stephenson]

I use a socket from a set if I can find the correct size. With the open end towards the bearing, it gives a convenient flat side to push against. A drill press is usually sufficient to do the job.

[Jon H]

7 hours ago, Engine Doctor said:

Jon says heat wont work but I have to dissagree

 

I do, and im right 😛 

 

At least, mostly. As always i post the advice that is guaranteed to work in all cases. Some laser engines will have their bearings come out with a little heat, and some ( a large some) will not....at least, not at safe temperatures. Over the years some tweaks were made to bearing fits after in service experience. The 180 style front housing in particular has a very tight fit as some bearings spun in early engines if they ran a bit hot. You can warm it up if you like, but you need to press them out in the end anyway as you risk damaging the housing using heat alone, so just cut out the middle man. 

 

There were also cases of ham fisted modellers melting parts of their engine with blow torches and the like trying to gear bearings out, even the easy ones. Admittedly, using a press has also caused issues for some with bearings crushed into pieces, but i guess no process is immune to..err...modellers. 

 

21 hours ago, Martin Harris - Moderator said:

Jon built all of the later Laser engines (and serviced any that were returned to the factory) so you can take what he says on this matter as gospel. 

 

You would think, but no, after 13 years working there i came to realise that everyone apparently knows more about it than me. At least, in their own minds anyway. 

 

 

In any case, i will always favour pressing a bearing out rather than cooking it out. Done correctly its a perfectly safe operation. Not always possible of course, OS rear bearings tend to not allow access so its heat or nothing. 

 

22 hours ago, Paul De Tourtoulon said:

Back from holiday jon ?

 

no, i just get a nervous twitch when you post something ridiculous so felt compelled to deal with it before i had a seizure. 

 

Stainless bearings are not a brilliant idea either by the way as they are softer than normal ones. 

[Tim Flyer]

This thread was a just an attempt to be informative rather than a request for instruction or judgment. It was not a criticism of the engine as all bearings are subject to failure. I may possibly be slightly out on the age of the engine as run three 180s and have swapped them occasionally between planes and the years pass quickly!  I’m a bit of a perfectionist and noticed slight play so just sorted it out.  
 

I am a competent home mechanic and have changed bearings in model engines and bikes costing thousands for decades with success. Learning how to use a drift is a useful skill and can be done without damaging shells. I have various sets of blind pullers but drifting was easier in this case. 

 

I am also very familiar with tuning four strokes and especially Lasers with Jon’s instruction .  I have left no visible damage on the engine and it runs perfectly well. 

 

I have also have had the privilege to watch Jon installing and removing bearings in the Laser factory so I do know how it should be done properly with his expert guidance.
As Jon says the housing on the 180 is very tight fit so it required careful drifting and a safe level of heat on its own was not enough. The engine is in perfect condition and my bearing change left no mark. I used a correctly sized bearing press to push the bearings back in . 
 

 

 

Edited August 8 by Tim Flyer

[Paul De Tourtoulon]

I couldn't find the information, but I am looking for the timing for the Laser 180 from a Frenchman who can't find it, he insists that it isn't the same as the 150, any help for him would be appreciated, thanks Paul.

[Jon H]

Note the position of the cams before you take it apart and then just put them back as they were. 

 

 

[Paul De Tourtoulon]

25 minutes ago, Jon H said:

Note the position of the cams before you take it apart and then just put them back as they were. 

 

 

It isn't mine, the man has taken it apart without checking first,,,

[Jon H]

21 minutes ago, Paul De Tourtoulon said:

It isn't mine, the man has taken it apart without checking first,,,

 

I know, i just enjoy pointing out the obvious mistake. 

 

I will never understand why people dismantle complex equipment with care free abandon, then get upset when they cant work out how to put it all back together as they forgot how it all went. It just baffles me completely. It takes but a moment to note/mark/photograph the relevant parts and build your own reassembly guide so why dont people do it? 

 

Anyway he's going to have a difficult time as the 180 had 2 or 3 different timings over the years and there is no chance at all i can explain how to work it out as, frankly, i cant remember the older timing myself as its been 10 years since i did one. 

[Paul De Tourtoulon]

Thanks, I will tell him,

[Ron Gray]

Try this.

 

https://www.laserengines.com/cam-timing/

Edited November 11 by Ron Gray

[Chris Walby]

54 minutes ago, Ron Gray said:

Try this.

 

https://www.laserengines.com/cam-timing/

  ?

[Ron Gray]

Oh yeah!