By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

ASP prop driver stuck!

All Topics | Latest Posts

Search for:  in Thread Title in  
Keith Miles 210/08/2019 17:19:21
301 forum posts
6 photos
Posted by Alan Gorham_ on 10/08/2019 17:14:05:
Posted by alex nicol on 10/08/2019 10:14:23:

I could be off the mark here, from memory I think the ASP also has a woodruff key that locates the prop driver?

Alex

Someone did....

Wasn’t me!

smiley

Keith Miles 210/08/2019 17:23:45
301 forum posts
6 photos
Posted by Martin Harris on 10/08/2019 16:05:20:
Posted by Keith Miles 2 on 10/08/2019 15:48:48:
Posted by Martin Harris on 10/08/2019 15:18:24:

This is what I use (bearing separator) and no engine has ever given more than token resistance to its efforts:

20171001_115601.jpg

One day I might find a better piece of steel for the bridge piece but it's always worked so far.

It's difficult to see how enough wear would occur to close up the tolerances enough to lock the engine. Are you sure there's no washer supposed to be there? Although my keyed 180 has one, I didn't see one shown in the parts diagram when I checked earlier...

Edited By Martin Harris on 10/08/2019 15:26:22

Thought about that method, but there is currently only a few thou gap between prop driver and crankcase so probably would not be able to get that in even if I had one.

No no no! Please don't think I was suggesting levering it off!

It fits into the machined groove in the middle of the driver. Tighten the bolts and if it doesn't pop off easily, strike the bar smartly over the prop nut...

Edited By Martin Harris on 10/08/2019 16:08:35

Ah, sorry!

Got it now!

DuhI

Keith Miles 210/08/2019 17:29:42
301 forum posts
6 photos
Posted by bert baker on 10/08/2019 16:22:27:

Have you tried knocking it on further with a deep socket or bit of tube

???

I’m trying to do the opposite!

Keith Miles 210/08/2019 18:10:37
301 forum posts
6 photos
Posted by Martin Harris on 10/08/2019 16:54:24:

Re-reading the OP it has just struck me that there was no mention of removing the driver at any time. This deepens the mystery a little and leads me to start wondering about a bearing or crankshaft failure...but I'm struggling to work out quite what could have happened?

Nope, driver has never been off and I reckon I might have remembered it if it had!

In fact, I’ve never taken anything off a four stroke other than glo plugs and rocker covers!

Yes, Martin, a mystery indeed which has a number of people puzzled. Immediately before refitting the cowl, prop and spinner as I’ve done many times for various reasons, the engine was as sweet as a nut and running absolutely fine. It still feels okay now that I can turn it by hand. No grittiness or similar in the bearing that I can detect.

My main concern is that the prop driver could jam again unless I can nail down the cause. It isn’t as if I tightened it with a spanner and a metre long extension bar!

As I said, though, this scenario could not happen with keyed type arrangements so this one is making me a little nervous and certainly cautious!

I also wish that I’d noted the prop driver/crankcase gap unless someone on here can help? Might be giving Just Engines a ring on Monday, anyway.

I must say I am a little reluctant at present to resort to anything more than a heat gun, then again I don’t want to spend any more money on tools that might never be used again although I could source a kindly lender or two!

My best hope is that I can get the prop driver off and perhaps replace it along with the collet assuming I can track down the necessary spares!

Viv Letherby10/08/2019 18:30:30
avatar
9 forum posts

Give Brian Winch the details, his email follows every article he writes for RCM&E. I've found him very helpful with such problems.

Denis Watkins10/08/2019 19:27:30
4177 forum posts
83 photos

Exploded view of parts Keith

Screenshot png, converted to jpg, hence adverts

screenshot_2019-08-10-18-46-37 (1).jpg

Martin Harris10/08/2019 19:33:20
avatar
9160 forum posts
229 photos
Posted by Keith Miles 2 on 10/08/2019 18:10:37:

I must say I am a little reluctant at present to resort to anything more than a heat gun, then again I don’t want to spend any more money on tools that might never be used again although I could source a kindly lender or two!

My best hope is that I can get the prop driver off and perhaps replace it along with the collet assuming I can track down the necessary spares!

I can't think of any reason why the driver would have moved back unless it had either been spinning in the hub for an extended period (not really possible) or had cracked, allowing the taper to over spread. However, you would assume that it would then have come off very easily! There is a direct path from the collet through the bearing hub to the shoulder of the crankshaft - that dimension can't change without the intervention of a superhero giant gorilla with the aid of a 36" Stillson wrench!

I can't see any scenario that would resist a good pull/shock blow from a rigid extractor - perhaps an idea of your location might elicit an offer of help?

Keith Miles 210/08/2019 20:16:21
301 forum posts
6 photos
Posted by Denis Watkins on 10/08/2019 19:27:30:

Exploded view of parts Keith

Screenshot png, converted to jpg, hence adverts

screenshot_2019-08-10-18-46-37 (1).jpg

Thanks, but I already have the one that came with the engine!

Denis Watkins10/08/2019 20:20:53
4177 forum posts
83 photos

Well use the diagram to determine, the parts that went on, will come off

Keith Miles 210/08/2019 20:30:01
301 forum posts
6 photos

Martin,

I share your bewilderment.

As for assistance, I have access to a few retired engineers if necessary. One is already aware of my problem and is equally bewildered!

Keith Miles 210/08/2019 20:31:56
301 forum posts
6 photos
FPosted by Denis Watkins on 10/08/2019 20:20:53:

Well use the diagram to determine, the parts that went on, will come off

I have and, currently, they won’t, as explained in my previous posts! That is what the thread is all about as per the title!

Edited By Keith Miles 2 on 10/08/2019 20:36:24

Denis Watkins10/08/2019 21:16:20
4177 forum posts
83 photos

Try this Keith, put the motor in the freezer now until morning

In the morning, boil some water and pour into a deep mug.

Get a hardwood clouter nearby

Take the motor from the freezer, the put all of the aluminium prop driver into the boiling water

Give the the hot prop driver a clout with the hardwood

Repeat the aluminium warm up as necessary but the crankshaft should still be frozen

You see the idea, small crankshaft, large prop driver

Keith Miles 210/08/2019 21:54:09
301 forum posts
6 photos

For those who are not yet bored, some visual info for you!

Note heavy duty removal tools which, thus far have only increased the prop driver to bearing housing clearance from nil (i.e. stuck solid, couldn’t turn engine by hand, even with the prop on!) to almost nil (so that I can now turn the driver with my fingers!). Note also, the apparently previously successful home brewed adaptor that I borrowed. Yes. It should be straight not bent which makes me wonder if the previously suggested wiper puller (which I did look at online) wouldn’t end up the same way!

Thanks for all constructive suggestions including the recent freezer/ boiling water one although whilst understanding the theory, if the hardwood clout doesn’t work, warming the driver again I would have thought will unfreeze the crankshaft but happy to give it a go if necessary. I also forgot that I have another heat gun (1500w rather than the 900w previously used).

Edited By Keith Miles 2 on 10/08/2019 21:59:07

Keith Miles 210/08/2019 23:09:45
301 forum posts
6 photos

Keith Miles 211/08/2019 00:31:58
301 forum posts
6 photos

Have twice uploaded a photo, seemingly successfully, but it has disappeared when I log back in.

What exactly is the correct process because I don’t understand the info that pops up when I click the camera icon?

Have, instead, been copying and pasting on I-pad from my photos folder. Seems all that does is leave a small square in the message box!

Martin Harris11/08/2019 00:38:53
avatar
9160 forum posts
229 photos

You need to upload photos (.jpg) to your album on the forum site first. Click on the albums tab at the top of the page to start the process.

Then when you want to include a picture you position the cursor and click on the camera icon.

You can also link to a photo on the web using the icon on the left of the camera one.

I think there's a guide somewhere in the "stickies"...

(there is - look here ...and then here.)

Edited By Martin Harris on 11/08/2019 00:43:04

Keith Miles 211/08/2019 01:27:45
301 forum posts
6 photos

Martin, thanks for the photo posting info, I’ll get on the case tomorrow...oops....later today. Bedtime!

I have found some photos on line of the ASP80 and can now confirm that, somehow, the prop driver on mine has DEFINITELY moved back too far because there should be a very visible gap between it and the bearing housing.

So, it definitely needs removing and the reason ascertained for the failure!

The saga continues!

Engine Doctor11/08/2019 08:56:23
avatar
2408 forum posts
31 photos

Hello Keith . You will probably find that the prop driver has split allowing it to go further onto the tapered collet and foul the crankcase. It happens quite a lot on ASP etc as the prop driver seems to be made of varying hardness of alloy . It will need a replacement. Just engines apparently still stock parts for them .

cymaz11/08/2019 09:06:18
avatar
9019 forum posts
1187 photos

Have you considered cutting it off. Drastic I know.

bert baker11/08/2019 09:57:48
avatar
1524 forum posts
317 photos

Or you could set the nut on the crankshaft at the end And gently tap it in slightly with a mallet,

oh is that the time

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E! 

Latest Forum Posts
Support Our Partners
electricwingman 2017
Slec
Wings & Wheels 2019
Sussex Model Centre
CML
Cambridge Gliding Club
CADMA
Advertise With Us
Sarik
Latest "For Sale" Ads
Has home isolation prompted you to start trad' building?
Q: The effects of Coronavirus

 Yes - for the first time
 Yes - but Ive bashed balsa before
 No - Ive existing projects on the bench
 No - Im strictly an ARTF person

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us