850 Destruction

[Snowbird]

Can you drill and helicoil, they are easy to do but best done on a pillat drill or mill to keep tap straight.

[dapleb]

Don't mind if I do .. lickety lick.



Head looks good.



Bugger about that bolt. Not much metal aboot that hole?

[dablik]

I've drilled the original bolt out cos it was loctited with red and not blue, however it's quite shallow so cant really be redrilled to helicoil (done a good few) and the smallest helicoil wont fit me thinks, as daps say's not much metal around the bolt as i 1st thought maybe one size up to M8 but reckon it's a bit dicey so, now i'm thinking of drilling straight through the side case so a bolt right through the width of the side will support where the aluminium is drilled out, just might have to take it to the engineering shop for an opinion..

[Catteeclan]

7mm bolts are available?

[Snowbird]

How about a weld up and redrill option.

This post was last modified: 09-08-2019, 06:23 AM by Snowbird.

[dablik]

7mm bolts are available?

 

Thanks, i did notice that last night might be an option possibly.

[dablik]

How about a weld up and redrill option.

 

I did consider that also but, would need advice from eng shop as would need to be the correct grade alloy, otherwise if it's to soft were back to square one, i was pursuing the helicoil option again last night which might be vialble, said hole actu.ally only has a thread depth of approx 5mm so if it was possible to drill to a further depth off 5ml and put in a 2D or 2.5D helicoil.

[Snowbird]

Is there any reason that hole can't go all the way through to give a bit more thread for a slightly longer bolt? Also check out twinserts as they can take a bigger hole back down to original (a helicoil in a helicoil), we used some at work as one of the engines we do is a b'stard for pulling out cylinder studs and then pulling out helicoils leaving a stripdown and weld up the only option but twinserts have got us out of a few sticky situations.

If we can do it to aero engines a tdm should be fine, I'll bet yamaha castings are better quality than teledyne continental, the phrase 'aircraft quality' usually means a trail of paperwork for something that's worse than you can get off ebay.

[madmopedracer]

what about a good quality chemical metal and retap

its only for retention and not under pressure like a cylinder head bolt

[dablik]

Is there any reason that hole can't go all the way through to give a bit more thread for a slightly longer bolt? Also check out twinserts as they can take a bigger hole back down to original (a helicoil in a helicoil), we used some at work as one of the engines we do is a b'stard for pulling out cylinder studs and then pulling out helicoils leaving a stripdown and weld up the only option but twinserts have got us out of a few sticky situations.

If we can do it to aero engines a tdm should be fine, I'll bet yamaha castings are better quality than teledyne continental, the phrase 'aircraft quality' usually means a trail of paperwork for something that's worse than you can get off ebay.

 

Cheers, my 1st idea was to do just that,drill right through, i imagine a bolt all the way through will hold up the integrity of the c.case as it's fulla metal, also been having a look at ideas re inserts.

what about a good quality chemical metal and retap

its only for retention and not under pressure like a cylinder head bolt

 

Yep i have Milliput which goes off really hard so it's an option, either way if i do it myself the thread hole will have to be longer, and i think it only torques to 12nm so some locktite around the housing could help also.....need to ponder awhile..

This post was last modified: 09-08-2019, 05:35 PM by dablik.

[dablik]

The thread hole in question is actually a blind hole so dont know if that should make a difference really to how it's fixed so, dropped at the shop this morning for a proper fix, ya man was off today so not sure if it will be an insert or summit else.

[dablik]

Got some shimerooing in on the bench.

[attachment=o12379]

 

 

Specs are....... Inlet 0.15 - 0.20 & Exhaust 0.25 - 0.30

 

 

                     Cyl 1                                             Cyl 2

Inlet   0.18     0.19     0.19                        0.19    0.19    0.18

 

Ex           0.29       0.29                                   0.29    0.29

 

Be interesting to see how quickly they tighten up once running.

 

 

[dablik]

Been a bit quiet while awaiting parts, been painting which is really frustrating outside, now all the parts have finally arrived i can crack on..

 

Got a pair of these today, lovely quality, and a rotor to replace the destroyed one offa me boyfriend you know who you are 

[attachment=o12455]

[alanfavell]

:drinks:

 

"It'll all be over by Christmas
".............  :hide:

[dablik]

?????????

[alanfavell]

Pressie to yourself :good:

[dablik]

Things are not going as planned visited Aircooled Sunday morning to beg borrow and steal some tools and udder stuff and as the afternoon got sunny took advantage and got a little more painting done.

 

I wanna know who stole the thrust washer then !! Haynes makes a point of telling you not to lose it but i aint got one in me replacement, and remember my original rotor got binned so no reference from that.. not one in the replacement starter i have either, i wondered if Haynes had made a goofy but Fowlers fiche verified it as well, guess i better get one then....you'll have a lot of fun iffin you go lookin for oneodem daps me old fruit

[attachment=o12464]

[attachment=o12465]

 

Also previously dismantled the output shaft as far as possible without resorting to pulling cogs of with gear pullers and ordered a replacement circlip per Haynes method of measuring only to find the fit is a bit looser than i would like, so phoned the nice chaps up at simply bearings for a bit of circlip info and repalcement on the way, had been wondering iffin the mk1 output shaft circlip (which is actually a snap ring) would fit the mk2 shaft but the mk2 2001 is approx 3mm wider in girth around the shaft groove, whodathunk it ?

 

And while i think on, the rotor windings bolts are always a pita to get out and often get drilled out, i wonder if they were originally staked like the other bolts in the pic above ??

 

Onwards..

This post was last modified: 09-09-2019, 06:39 PM by dablik.

[wicklamulla]

Do ya mean the 4TX output shaft has a larger diameter versus the 3VD one? I guess they are different part numbers.

[dablik]

The 2001 shaft for sure, dont know about previous mk2's though, i measured the shaft groove for the external circlip and compared it to a 92 mk1, 2001 is bigger,not checked part numbers though.

[dapleb]

So that washer should be captive in the rotor assembly dabbers!?? Don't think I have any other rotors pulled other than that 9er Juan.



Will have a brevity though not really sure what I'm looking for aS can't remember that part.



Weird that it wouldn't be in that spare rotor if part of assembly!!

This post was last modified: 10-09-2019, 05:31 AM by dapleb.