[stroker]

Nice, thank you for that. Dont take this the wrong way, but thats a weird way of jamming the crank shaft. I would just take the clutch cover of and put an aluminiun washer/spacer between the two gears, works like a charm everytime and doesnt leave marks.

[Old Painless]

I didn't really have anything better to hand.

I've used a block in the gears before and managed to chip one of the cogs teeth. It needed replacement.

This post has been edited by Old Painless: 08 June 2008 - 08:46 PM

[PJ ENGINEERING (PROX)]

Old Painless, on Jun 8 2008, 09:14 AM, said:

As well as the above i noticed on the Prox website where you can compare the piston kit pictures and specs that the single ring and twin ring Wiseco pistons are different sizes but fit the same engine ? The twin ring piston is wider (and more expensive).

Now i have looked on www.pro-x.com and www.wiseco.com and can not see any photos ? or different sizes.

Wiseco list 8536M05600 to fit a std bore of 56.00mm and has 1 piston ring and a flat top,
The dome top is a 854M05600 still a 56.00 mm bore but has 2 piston rings

The 853 is £78.37 and the 854 is £90.98 you pay more for a twin ring piston as it has 1 more ring.

I have a OEM cylinder here 279B that has been Replated to 56.00 mm I would want £188 for it.

If you send me your crank in before you order your parts i will fit the rod to the crank for free.

Hope this helps
Yours Paul

[Old Painless]

Oooh, freebies ! :plus:

Now i have saved on the crank rebuild i might as well go the whole hog and have the cylinder too mate, ta very much.
So now i get the OEM cylinder i wanted and the forged piston too ..... Muahaha

The poor little rear wheel is going to suffer. lol

Thats a very nice price you've given me for the full rebuild kit Paul, thanks very much, i appreciate it. It will be nice to have it working smoothly again without it being like sitting on a road drill at idle.

[cagivamitoevo]

Old Painless, on Jun 9 2008, 04:09 PM, said:

Oooh, freebies ! :plus:

Now i have saved on the crank rebuild i might as well go the whole hog and have the cylinder too mate, ta very much.
So now i get the OEM cylinder i wanted and the forged piston too ..... Muahaha

The poor little rear wheel is going to suffer. lol

Thats a very nice price you've given me for the full rebuild kit Paul, thanks very much, i appreciate it. It will be nice to have it working smoothly again without it being like sitting on a road drill at idle.

if you contact bdk race engineering he will give you a replate OEM cylinder for £97 + your old cylinder iirc but have to say good deal paul

[cagivamitoevo]

Old Painless, on Jun 7 2008, 12:25 AM, said:

By special request :

http://www.savefile.com/files/1594722

Feast your eyes people.

I am assuming you don't need a blow-by-blow description although i could do one.

The guide assumes several things: -

You have the following tools-

Basic allen keys, T-bar allens are better
Basic socket set including 17mm and 22mm sockets
Basic screwdriver set including 4mm flat blade and No 2 pozi/philips
Dead blow hammer
Flywheel puller
Protective gloves, many, many pairs
Facilities to avoid getting oil everywhere, newspaper etc
Drain all the fluids before you get a couple of litres of oil and coolant on your carpet
Strip the engine so all you have is the bottom end
Half a day to spare
I ran a tap and die over all the bolts i pulled out and into each hole on the outer casing and engine mounting bolts, also had to drill out and re-tap a snapped bolt in the fairing support bar

A good thing to get would be a decent pair of pieces of wood to block the conrod with as i had to use spanners and screwdrivers, you'll see. Not pretty. 2x1 would do

Its not a perfect guide but it will have to do as its 1.20AM and i just finished taking photos.

4.5 hours from start to finish.

I'm f*cked, off to bed.

Sorry for any spelling mistakes, can't see the screen anymore. lol


Reders, your welcome. :thumbsup:

good effort OP perhaps a detailed write up for each picture will make it spot on mate then my topend rebuild thread and your bottom end thread can be stickied aye good job

[Old Painless]

My old cylinder went in the bin a long time ago mate.

From talking to paul i think he knows what he is on about. I trust him to sort my crank far more than the dumbf*cks at SEP in Kegworth.

With the freshly replated cylinder from Paul and the Wiseco piston i know i have a 56mm cylinder and a 55.96 piston giving a 0.04mm clearence in the bore which is exactly the minimum reccommended in the WSM, i have checked it out (0.05mm +/- 0.01mm).

If you need a more detailed write up for the pictures and the WSM doesn't suffice you shouldn't be doing it yourself. lol

[cagivamitoevo]

Old Painless, on Jun 9 2008, 05:08 PM, said:

My old cylinder went in the bin a long time ago mate.

From talking to paul i think he knows what he is on about. I trust him to sort my crank far more than the dumbf*cks at SEP in Kegworth.

With the freshly replated cylinder from Paul and the Wiseco piston i know i have a 56mm cylinder and a 55.96 piston giving a 0.04mm clearence in the bore which is exactly the minimum reccommended in the WSM, i have checked it out (0.05mm +/- 0.01mm).

If you need a more detailed write up for the pictures and the WSM doesn't suffice you shouldn't be doing it yourself. lol

sometimes its easier to understand it when someone as skilled as yourself ( :lmfao: sorry made myself laugh ) writes it because the manual is sometimes abit vague thats all

This post has been edited by cagivamitoevo: 09 June 2008 - 05:14 PM

[Cagiva4ever]

hey ! dude

Wössner and wiseco needs defenitely a 0,06mm clearence. im not saying it without experience.

ring end gap must defenitely be 0,25~0,3mm.

bye:)
m

[Old Painless]

The single ring piston has a clearence of 0.05mm and the twin ring 0.04mm, the single ring piston is listed as fitting the Mito 'sport'. Probably due to higher compression and leaner runing the psiton will expand more and with the single ring not be as thermally effecient at transfer than the twin ring, just guessing really.

The piston is the correct one as listed in the parts library on the Wiseco website and it matches the information in the Cagiva workshop manual. I can't see any reason for it be wrong ?

From what i read (lol, the internet of many wonders) a forged piston is stronger than a cast piston, i have seen my bikes eat so many pistons its not even funny.

Slightly lean - seize

Cold weather - seize

Just past 8000 kms - seize

I'm f**king sick of it so i am going for the best i can afford, which as it happens is the very best PJME sells.

Forged pistons seem to have come a very far way from there roots and i have my doubts as to the longevity of the mitaka parts i was going to buy, i would never buy hand tools made from the same stuff as those pistons.

The expansion of the piston is only a problem if the piston cannot get enough cooling, the mito has by far and away the biggest radiator i have ever seen on a 2 stroke bike. This is also the reason i am enquiring about increasing the flow via altering the coolant transfer ports around the head/cylinder in another thread.

Is there any definite information you can give me such as a link to something i can read ?

[Cagiva4ever]

Hi !

as a adding to topic, here is a Zip file about 7-Speed '89~91 engine explode views.
"bottom engine" same as evo1 exept hex cut Primary Drive and heavyer Clutch casing cover/FlyWheel cover.

http://www.badongo.com/file/7433902

bye:)
m

[Cagiva4ever]

Hi !

W.S.M(s) lists cast pistons and W.S.M clearences are ONLY4 casted pistons.

forged pistons need bigger clearence than 0,04~0,05mm. they need the 0,06mm, also forged pistons are more delicate to ringend gap.

ohh and as experience, my client (carting racer4 10years) seizured his assy as the clearence was too small (0,04) thx to gaywiz.de. unfortunately this pro didnt check the items b4 re-assembly. runnin in period was carefully started and done with my notes with evo1 parts..it seizured at 200km

Asso Werke boxes have sometimes the label on them saying 0,04~0,05
Wössner has manufacturers recomandation for 0,06. i think Wiseco is the same

bye:)
m

This post has been edited by Cagiva4ever: 10 June 2008 - 05:56 PM

[Cagiva Gezzer]

Cast expand less and more uniform than forged piston. I'll stay out of this argument, but why not just use a OE (forged?) Asso Werke one? I had a long debate with PJ years ago about OE and pattern pistons.

From distruction of some units i came to the conclusion that pattern ones were very britile units and OE ones were much more ductile. -> Cast Vs Forged conclusions.

[Old Painless]

I can't find any information about the sizes of the OE pistons though ! The Asso Werke website is down. ffs

The Wiseco piston information from there selection list gives that exact piston which gives a 0.04mm clearence. Why would they make that specific piston for that specific bike if it doesn't work properly ?

Why would PJME sell that piston for that bike if it doesn't fit ?

Bearing in mind Wiseco and PJME know an awful lot more about pistons than me.

This post has been edited by Old Painless: 10 June 2008 - 06:47 PM

[Old Painless]

If the OEM piston is an Asso Werke and is forged and the WSM states a 0.04-0.06mm clearence surely the Wiseco piston will fit being as it too is forged, you can get at what i am thinking here i hope.

[Cagiva Gezzer]

In theory, yes. However Wiesco are not know as Siezeco for no reason. (that goes back to people using cast clearances with aftermarket forged pistons).

All depends if an Asso Werke unit is cast or forged. PJ will say cast. I'll say forged.

[Old Painless]

Well i need to know the sizes before i pay for it and fit it, obviously.

The asso werke could be some fancy high silicone job ?

halp.

This post has been edited by Old Painless: 10 June 2008 - 07:17 PM

[Old Painless]

The Vertex piston for the RS125 has a clearence of 0.02mm. The vertex piston is a the same size as OEM even for there 'racing' kits from what little i can see.

It looks from the information i have that the Wiseco piston for the mito uses a clearence which is double that of standard, if cross comparisons can be made like that, which i wouldnt trust a few hundred quid on.

Thats if the RS uses a similar cleaerence and if the mito wsm isnt for the wrong type of piston *sigh*

This post has been edited by Old Painless: 10 June 2008 - 07:31 PM

[Cagiva Gezzer]

The way i've always approached it is to buy the piston, give it to PJ / Stan Stephens and ask them to plate the cylinder to the piston.

[rambo_sil]

you lot know what your talkin about n i dont know much but ive got a standard barrel and a twin ring wiesco piston

Ive done 350 mile throttle response is alot sharper and smother, ive done 120 mile in one day and had no problems

Ive taken her up to 8000 a few times and not had any probs in 350miles so it must be a good fit if ive not had any problems and on stan stephens website he says forged pistons made out of same material as barrel so expand the same a heat transfere better