Evo 58GX mystery part
 

This look familiar to anyone?

I can't find it on either the MVVS or the Evolution exploded views. Crankshaft collar EVO30010208

I have my own theory as to what it might be for!

http://www.horizonhobby.com/Products...ID=EVO30010208

RE: Evo 58GX mystery part
 

It measures: ID 15mm OD 19.5mm width 6.5mm

RE: Evo 58GX mystery part
 

Pretty sure this is the order,I sent this pic to P.E about shim order,how is my 58 runnin?

RE: Evo 58GX mystery part
 

http://www.horizonhobby.com/ProdInfo..._Explosion.pdf

RE: Evo 58GX mystery part
 

MVVS has used two types of prop drive in the past. One with a steel insert, on which the seal could rest with the sealing lip. This has a lesser taper crankshaft.
The other version had no steel insert. With this version, the steel ring was fitted with loctite in front of the bearing so it could provide proper sealing combined with lipseal 0204. How these parts work together is not very clear from the exploded view.

Current production has the steel insert in the prop drive. If fitted properly, the crankshaft has about 0.1mm axial play before the insert buts up against the front bearing. Max play is 0.4mm.

RE: Evo 58GX mystery part
 

Thanks Pe, you confirmed my theory, two different prop drives. Not sure how or why I received one but it came with my gaskets etc.

Hi Skip,
The 58 is a monster, I pulled it out of the Yak to do some pre season touch ups. I'm dropping some new bearings in, drilling out the jet in the 201, inspecting the reeds, new diaghrams and finishing with new gaskets. It's going to be a great season :D

RE: Evo 58GX mystery part
 

201 on the 58? The 201 blong 45!

RE: Evo 58GX mystery part
 

Hi Pe,
I thought the 201 would be okay on the 58 as long as the high needle was drilled out to 1.2 mm?

I'm having a hard time locating, I believe it was a 603. It crosses to something else which crosses to something else and it now comes with a primer bulb [:-]

RE: Evo 58GX mystery part
 

The wt201 will do if drilled to 1.2mm.
However, the power will be lower than when using the HDA189B that is standard for the 58. HDA has 16.7mm venturi, the WT201 only 13.5mm

RE: Evo 58GX mystery part
 

I can't imagine getting more power, my god! :D

Perhaps I should just rebuild the stock carb then!

Thanks

RE: Evo 58GX mystery part
 

What is the stock carb on your engine? It should be the HDA189

BTW, The photo that Skip published shows the right order of the parts.

RE: Evo 58GX mystery part
 

So, looking at Skip's picture, I don't see any shims in mine.

The picture is a little blurry. Are all three shims pulling the crank back or are two of them around the rod?

Also, is the small round spacer not in front of the front bearing? In the picture it looks like it's behind the front bearing.

I may have to get some shims!

Carb, yes HDA 189B. Skip says he hates it ;)

RE: Evo 58GX mystery part
 

I cant hate it! I just threw it in the pile cause I didnt have a kit on hand,anywho,I think some dont use shims but you will have to verify that w/P.E. or only certain amount of shims on certain assembly runs,or somthing like that,I would not touch your carb untill engine overhaul to verify changes if any,what style exhaust are you using,the big carb might be good for t/pipe,good luck

RE: Evo 58GX mystery part
 

Hi Skip,
14 inch custom header with the MTW RE2 tuned pipe, instant throttle response! I would like to load the engine to 6500 RPM this year; I have a 26A Xoar on order.

RE: Evo 58GX mystery part
 

For IMAC, 14" header with RE2 is minimum length. If you want to go to larger props and keep rpm down 15.5" would be even better.
PS
all shims should be added AFTER fitting the engine and determining axial play, which should not be eliminated altogether. Shims to be placed between prop drive and front bearing. With loose sealing ring, between prop drive and ring.

RE: Evo 58GX mystery part
 

I received my bearings today, plus a free Boca Bearings mouse pad with a conversion chart, love it!

I installed the bearings and crank, the play is quite heavy 1.5 to 2mm. There are no shims any where!

Recommendations?

RE: Evo 58GX mystery part
 

Is that AFTER you torqued down the prop drive to the shaft?

RE: Evo 58GX mystery part
 

Yes, it was like this last year as well. I honestly thought it was getting held up on the key so I tried it without, same thing.

RE: Evo 58GX mystery part
 

Make a shim 0.1mm less than the axial play, and insert it. Max axial play should be smaller than or equal to 0.3mm.</p>

OR,</p>

send the engine to MVVS for overhaul. They have a ISO qualified maintenance workshop.</p>

RE: Evo 58GX mystery part
 

Brass shims okay?

RE: Evo 58GX mystery part
 

yes.</p>

Are you sure you torqued the prop drive on well?</p>

Sequence:
1) insert 12.10 M8 bolt in crank thread. On the bolt is a nut and press ring that butts up against the steel insert of the drive so the mounting force is on the inner drive part only.
2) while holding the prop drive, torque the nut to 33Nm, pulling the drive up the taper
3) remove the 12.10 M8 bolt, and fit the MVVS central bolt with flange. Torque with 25Nm.
</p>

now there should be 0.05 - 0.3mm axial play.
When fitting the propeller, be sure not to torque the central nut more than 20Nm (is not very much!)
</p>

RE: Evo 58GX mystery part
 

Thanks Pe
No, I never went through anything like that. I would have bet money that the crank was flush with the prop drive after I was finished. Looking at it now I see I have close to a 2mm space still.

RE: Evo 58GX mystery part
 

The "mystery part" proved useful. I used it on the hub with a nut and bolt and a large washer. I torqued the nut pulling the crank but I only gained about .010 I'm still looking at a large gap!

Brass shim coming up!

RE: Evo 58GX mystery part
 

I believe at some time MVVS used to bond the extra ring onto front of the bearing, thus providing a good seal between shaft and housing.
In my old model 43cc I replaced the front seal with a bearing and now have 2x 2rsr bearings up front, both bonded to the crankshaft  (loctite 648)