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Polini 165 install

PostPosted: Wed Aug 27, 2014 8:15 am
by Hoolio
Hi all - decided to log the installation of the Polini 165 cylinder kit.

Got the engine out and it's on the bench. Next step for tonight is to degrease and take off the mudguard/airbox assembly.

First question - I'm planning to get a thicker gasket made by gasketstogo.com to reduce the compression. The head gasket that came with the kit is a thin steel thing (feels like spring steel) with an embossed pattern, and the base gasket is a flat waxy card type gasket. I'm thinking that it would be better to make a thicker base gasket as it looks easier to copy, and maybe would be under less stress that the head gasket. Anyone have any ideas on this?

Re: Polini 165 install

PostPosted: Wed Aug 27, 2014 9:18 am
by Shaunbond
Thanks for sharing the progress it will be interesting to follow. :D

Re: Polini 165 install

PostPosted: Wed Aug 27, 2014 9:23 am
by tipper
'Tablet' is the man to speak to as he did exactly the same as what you are doing a couple of months ago. He hasn't logged on to the forum for a few weeks but he posts on the facebook group every day under 'Dave Tablet Smith'.

Re: Polini 165 install

PostPosted: Wed Aug 27, 2014 1:34 pm
by Howscoot
I've got a polini kit sat in the garage, I'm just waiting for the courage to do something with it. Keep us posted on how you get on

Re: Polini 165 install

PostPosted: Wed Aug 27, 2014 10:04 pm
by Hoolio
Cheers guys.
heh heh - I'm sure I'll make plenty of mistakes you can learn from.

First tip - use a proper hex head socket to remove the clutch cover bolts. I first used a socket with 18 indentations and it stripped the head of the bolt - they're pretty tight and pretty soft. NOTE - in the pic it says 10mm but it's really 8mm!
photo(9).JPG
use a proper hex socket for clutch cover bolts
photo(9).JPG (93.38 KiB) Viewed 10822 times

Got the airfilter/mudguard off and cleaned up the engine a bit with degreaser.
photo(10).JPG
engine a bit cleaner
photo(10).JPG (37.46 KiB) Viewed 10822 times

I sprayed the remaining clutch cover bolts and the bolts on the head end with WD-40 to get them more in the mood for shifting.

I'm kind of dreading the next bit (clutch cover off to get to timing chain) etc

Re: Polini 165 install

PostPosted: Thu Aug 28, 2014 7:58 pm
by tablet
I can't figure out how to put pictures on here !!!!

Re: Polini 165 install

PostPosted: Thu Aug 28, 2014 11:38 pm
by tablet
why are you removing the clutch cover ? are you upgrading the clutch as well ?

Re: Polini 165 install

PostPosted: Thu Aug 28, 2014 11:52 pm
by tablet
[ihttp://i1383.photobucket.com/albums/ah296/tablet647/IMG_20140527_150621198_zps3902b706.jpg[url][/ur[URL=http://s1383.photobucket.com/user/tablet647/media/IMG_20140526_154519681_zpsfa257afe.jpg.html]Image[/url][img][/im[IMG]http://i1383.photobucket.com/albums/ah296/tablet647/IMG_20140527_150601297_zps90c34556.jpg[/img][img][/im[IMG]http://i1383.photobucket.com/albums/ah296/tablet647/10333560_455101104625699_6820671134096990417_o_zps1f7ec50b.jpg[/img]g]g]l]mg][/ihttp://i1383.photobucket.com/albums/ah296/tablet647/IMG_20140527_150621198_zps3902b706.jpgmg]

sorry if these pictures don't come on - having a go at posting some

Re: Polini 165 install

PostPosted: Thu Aug 28, 2014 11:53 pm
by tablet
[uImagerl][/uImagerl]

Re: Polini 165 install

PostPosted: Thu Aug 28, 2014 11:58 pm
by tablet
ok - I've got the hang of it now [uImagerl][/url]
you can make your own with a piece of 1mm aluminium and some tin snips and a dremel ( or other rotary hobby tool )
[uImagerl][/url]
to drop the piston back 1mm I would use the base gasket ( as I have ) as the head gasket takes a lot more pressure

Re: Polini 165 install

PostPosted: Fri Aug 29, 2014 12:44 am
by tablet
Howscoot - do it bro , disconnect your gear and clutch cables ( easy ) take the carb off , disconnect the rear shock (remove the wheel first , and drain your oil out ) find TDC (top dead centre ) , I used a wooden clothes peg to then jam the fly-wheel so it wouldn't move , remove the 4 head studs and the cam cover , the cam sprocket is then accessible and it has a mark in the 12 o'clock position , remove the nut and slip it off , I then use a piece of garden wire in the position on the chain where it needed to be replaces on the timing sprocket , this will keep the correct position and serves as a way to re-thread the chain when you have changed the barrel and piston , remove the cam chain tensioner , slide off the cylinder head , there are 2 more nuts holding the barrel in place , remove them , carefully slide up the barrel , threading the wire through the cam channel , the piston is now free , remove the circle pin from one side of the piston , slide the piston wrist pin out towards the circlip side that you have removed , the pin might take a little persuading to start with but don't twat it with anything heavy , - ---------- reassembly ------- a good tip is to insert one of the piston circlips first , while you have the piston free , put the piston in place , slide in the new wrist pin , (fiddly bit ) replace the last circlip and make dame sure both circlips are in their groves , oil up the piston , you will have put the rings in place before you began reassembly ( I hope ) locate the new barrel onto the 4 guide pins , ( another fiddly bit , keep the band-aids handy ) as your new barrel gets to the pistion rings it will stop , you have to squeeze the rings to get then to enter the barrel , and you will trap your skin more than once , slide the new barrel down onto the new gasket ( or gaskets of you have fashioned a decompressor gasket ) while threading your garden wire attached to your cam chain up through the cam channel , replace the cylinder head threading the wire at the same time , replace the cam sprocket ( it only goes one way ) put the cam chain on before you slip the sprocket on , take the wire off before , the cam tensioner will be all the way out , you can wind it in from the small external screw , refit it , cam cover on , now check your piston is moving properly , no snags or drags , all bolts tightened up , engine back in frame , cables re-seated , shocker re-attached , plug in , DO NOT USE YOUR ELECTRIC START ,,,,,,,you will break it ( like I did ) , 500 miles with fresh oil and half throttle , oil change --------and as Bruce Forsythe used to say " that's all there is to it "

Re: Polini 165 install

PostPosted: Fri Aug 29, 2014 6:08 am
by Howscoot
Tablet thanks for the encouragement. Did you place the decompression gasket at the bottom or top of the new cylinder-your photos look like it went on the bottom but some articles I've read seem to suggest it should go topside, between the top of the cylinder and the head gasket.
Also did you use sealant between the decompression gasket and the cylinder- something like Stag Wellseal Gasket Jointing Compound.
Why do you think the starter motor packed in after you fitted the new kit and did you upgrade your clutch?

Re: Polini 165 install

PostPosted: Fri Aug 29, 2014 11:58 am
by Hoolio
tablet wrote:why are you removing the clutch cover ? are you upgrading the clutch as well ?

Tablet! Just the man!
I asked myself the same question last night. Nah not upgrading clutch just yet - was following the instructions in the Stella service station manual. Realised I didn't have to remove clutch cover.

I've ordered 1.5mm thick copies of the base gasket from gasketstogo.com (original is 0.5mm). I've ordered 2 of them. Howscoot do you want one when it comes (assuming it looks OK)?

Re: Polini 165 install

PostPosted: Fri Aug 29, 2014 12:53 pm
by tablet
Howscoot - I chose to put the decompressor gasket at the base of the barrel and not at the head because the head gasket takes a lot more pressure and should be made of steel , the purpose is to drop the piston 1mm , so whether you put it at the bottom or the top , it would have the same effect , you could use high temperature gasket seal if you want , but I used the new gasket and the supplied one , I have had no leaks yet , I think I put too much pressure on the starter , that's why it broke , should have used the kick only until it was run in a bit
Hoolio - the clutch in the star (stella ) is based on the cosa mk 1 , and is the same clutch that the 150cc uses so it should be ok for at least a while , my gut feeling is it is safer to increase the gap in the piston head from the base of the barrel rather than at the head , a blown head gasket would be possible if you weren't careful of what kind of gasket you used

Re: Polini 165 install

PostPosted: Fri Aug 29, 2014 12:56 pm
by tablet
tipper - I do come here quite often , but unless I have something to add or anyone I can help , I just don't bother signing in mate - I'm not one your idle chit-chat as you know (HAHAHA)

Re: Polini 165 install

PostPosted: Fri Aug 29, 2014 4:42 pm
by Hoolio
Tablet do you recall your approach to loosening the timing chain tensioner screw? I think mine was screwed in by the beefiest guy in the LML factory cuz I can't budge it and don't want to do my favourite strick of stripping the head. The Stella service station says to unscrew clockwise but is that right?

Re: Polini 165 install

PostPosted: Fri Aug 29, 2014 4:57 pm
by Howscoot
Tablet-thanks for the info mate.
Hoolio-you've answered the questions I asked you in my pm on here, thanks. Yea if you find that you've got a spare thicker head gasket at the end of the upgrade, let me know and I'll buy it off you.

Re: Polini 165 install

PostPosted: Fri Aug 29, 2014 10:46 pm
by tablet
Hoolio - anti- clockwise winds the tensioner strut in so you can re-fit it mate , no problem Howscoot , I'm here to help if I can my friend , you will both find you have very little increase in top end speed , but the other changes in the scooters behaviour are well worth the task at hand , it will walk up hills ( all but the largest ) in 4th , in 3rd you can keep 45 mph up all but mountains , and in general day to day use they are very egger to go , I love mine , I did before , but now I find myself wanting to go out with no particular place to go just to drive ---- hope I have helped , if you need me again , I'm like Superman ---- i'm always around

Re: Polini 165 install

PostPosted: Thu Sep 25, 2014 2:53 pm
by Hoolio
Cheers for that Tablet. I had been following the Stella service manual instructions which said to undo the tensioner before removing the timing wheel cog, but I followed your list of steps and took off the the timing wheel first and all was fine. The tensioner screw came undone after a soaking with WD40 and being able to get to it at a decent angle after the cylinder was off.

This "packer" gasket thing is really doing my sweed - the ones I ordered from gasketstogo.com were about 3mm short and the holes didn't line up properly, so a bit of a waste of 12 quid. I ended up transferring the gasket shape to an AutoCAD file and asked them to redo but have not heard back from them. Ended up ordering a piece of aluminium and will do it meself! Ordered 1.5mm 1050H14 aluminium.

I tried to upload the AutoCAD dxf file (well, converted to pdf) but the system wouldn't let me so rough jpg attached. If anyone needs the dxf file just give me a shout. I thought it might be handy if anyone could laser cut/water cut one.

Re: Polini 165 install

PostPosted: Thu Sep 25, 2014 3:15 pm
by Hoolio
Jeez have I really been doing this for a month?
:)