Bit the Bullet

[funky]

Hi all its been a while hope you are all well .
My XS started burning oil the old 75mm sleeves had been rebored to the max 77.5mm... not sure if the could go any further but 707cc pistons were now too small ring gap was at the top end of tolerance at the last rebuild.
Yes I have bit the bullet and have gone for the 750 big bore from heiden tuning, my old cylinder will be re sleved back to 650cc my next project after the big bore and shelved for the future.
The big bore kit is already prepared and ready to fit ......so stripped the engine and cleaned and preped the head, lapped the Valves and fitted new Valve stem oil seals ready for the kit to arrive.
Not sure what to expect in terms of performance but looking forward to the rebuild any advise would be welcomed as allways .
All the best Funky

 

[TwoManyXS1Bs]

Welcome back, Sir Funky!

I don't think that the Heiden 750 kit has the grooved relief for the cylinder o-rings. I believe that you simply omit them at install. Here's a thread:

http://www.xs650.com/threads/heiden-big-bore-cylinder-o-rings-not-allowing-jug-to-seat-fully.42832/

 

[funky]

Thanks TM I will see when it arrives I heard of some people not even fitting them to the stock engine

 

[funky]

Well have been busy today sorted the head out lapped in the valves removed the old sleeves if i order new 75mm sleeves do I have to state the size of the barrels or are they all standard the sleeves have 007 on them ??????? maybe James Bond owned the bike once all cleaned old gasket scraped off ready for big bore.

 

[nighthog]

Can't offer you any advice, just admiration for what you're doing. Hope it all goes smoothly and keep us posted

 

[funky]

Thanks Nighthog its not that difficult my trouble is i am not scared to try But this does have it down falls I have made big mistakes But I suppose thats how you learn

 

[funky]

I have a question for you chaps I am fitting the 750cc Big bore kit and will be using my BS34 stock carbs which i was running on my 707cc engine
Jetting is
Air 130
Main 137.5
Pilot 37.5
Mixture 1.5 turns out
I am worried about this as i dont want to wash the bores out running too rich or over heat due to being lean Any suggestions on jetting in preperation for the big bore. Or am i being a worry guts and should take a chill pill .
Your advise and wisdom would be greatly appreciated on this matter ....
All the best Funky

 

[TwoManyXS1Bs]

The 007 on the sleeves means that they were finish bored to 75.007mm.
Irrelevant to sleeve fitment into cylinder block.

What you're concerned about is the interference fit of sleeve into cylinder block.

Probably not an issue back in the old daze, when engines were only a few years old, but nowadays, with age, many heat cycles, unknown history, possible oil entrainment and fretting, I feel it's prudent to check the interference fits.

With all parts normalized to a room temp of about 70°F, you'll want the sleeve to be about 0.004"-0.005" (0.10mm - 0.12mm) larger than the hole in the cylinder block.

A 0.003" (0.075mm) interference is about as minimum I'd be comfortable with...

 

[TwoManyXS1Bs]

The 707cc is about a 9% increase over the original 650cc.
The 750cc is about a 6% increase over the 707cc.

By itself, not enuff to warrant immediate carb rejet.
Do all that fine tuning after it's running.


So, yes, a chill pill...

 

[gggGary]

Jetting; more about the exhaust and air filters than the cc...

 

[funky]

Thanks Gary and TM
I emailed Heiden tuning and this was the reply
hello

It depends on with open filters and a good free flowing muffler[what I prefer for a 750]
145 main jet 45 pilot jet and mixture screw 3 full turns open.
The other parts as standard.
Best regards,
Jerry

Food for thought i would say

 

[funky]

Hi all Update well i have cleaned everything and checked everything Again changed the cam shaft oil seals ,,,,,The big bore kit should be here mid week next week and i also have purchased some .........
PERMATEX® COPPER SPRAY I still got some Three bond but i am going to go for the copper sealant this time.
My old head gasket seems to indicate issues with the 3bond it looks as if it has burnt or carbonised
I was considering mountring the head gasket dry but to be honest it scares the out of me
Head is pretty flat 0.04 or .0015 not able to fit so i recon it about .0010 clearance
Just waiting for bits now.
Reading some threads on here about re-Torque every 20 to 30 K and doing that a few times will be on the cards for me as i did not do that previously which probably contributed to teadown and rebuild now just was not happy I want an engine that does not use oil up or burn it one can only live in hope ...
All the best funky

 

[funky]

HI all got the big bore kit the only paperwork i got was this ordered new gaskets obviously but what i dont know is ring gaps and piston clearances so have emailed them .... This is advertised as the only bolt on big bore kit on the market but it looks like the Mike xs type could be wrong ...What do you think

 

[TwoManyXS1Bs]

... it looks like the Mike xs type could be wrong ...

Huh???

 

[funky]

What i mean is..... mike xs sells a big bore kit also,,, just wondered if it is the same,,, do heiden tuning make them for mike xs or is there a supplier that makes the bigbore kit for both of them

 

[gggGary]

You are probably right Mike Legrande Leblonde went to the wholesale side of the business and (still?) sells the XS performance brand to XS retailers 'round the world.

 

[grizld1]

750 kits from Mike'sXS and Heiden Tuning are the same. Heiden and Lalonde both sold the same "XS Performance" line, including the godawful PWK knockoff carbs and the "drop in" billet camshaft (knockoff of the Megacycle 250-00 grind, but redesigned in a way that's guaranteed make your motor shake like a dog passing peach pits). I don't know who originated what.

 

[funky]

Hope you are all well...I have been busy started about ten this morning checked all tolerances then rebiult the top end and put the engine back in the frame Piston rings checked top compression ring 0.10 oil rings was fine out the box and the had to take a thou off the second wiper .
Email from Heiden tuning said they were ok out the box which they pretty much was
Piston to cylinder wall 0.06 then carried on finished about 10 this evening after cleaning up my tools engine started first try All seems fine fitted new carbon brushes to stator lovly bright lights now used copper gasket spray seems a good product torqued head to 40newton meters on main bolts and 16 newton meters on the 13mm bolts 10 on the little one at the back that easy to de thread .
I just need to run the engine in done a few heat cycles will take it for a spin on my next day off ...will re torque head after 20 miles or so and re do this a few times ...
All the best funky

 

[TwoManyXS1Bs]

... Piston rings checked
0.08 top
0.10 second
scraper was fine out the box and
the top rings was also had to take a thou off the second .
Piston to cylinder wall 0.06

What units are you using?

 

[funky]

Thousands of an inch . just looked at my post and there is a typo the trouble of posting after a long day at work .