How can I tell if my engine has been rephased ?

[007sparky]

Hi peeps , I have a question for all , I bought a project bike that's had an engine rebuild for sure , plus it's had a battery free ignition fitted but I wanted to check if its been rephased and need your help ! !

I can't contact the person who last had the bike so that's out of the question so how else can I tell ? ?
I thought well maybe by feeling the exhaust when running A May feel a timing difference ?
By the way not ripping the engine open either I need a damage free way of checking , regards mark ......

 

[650Skull]

If you cant tell by the sound. Take out both spark plugs, revolve the engine by hand till you have a piston at TDC. Have a look through the other spark plug and if that piston is at TDC then it hasn't been re-phased. Cant see the piston then it probably has, unless they left it out in the rebuild.

 

[TwoManyXS1Bs]

Or, if you have that deft feel, you could slowly kick it over, sensing for unequally spaced compression strokes...

 

[007sparky]

Cheers all , skull I feel dumber for not thinking of your method , can't understand why the engine was designed to have both pistons in alignment anyhow ? Obvious to me that it would rattle like mad

 

[007sparky]

I'm thinking it hasn't been rephrased as the electronic ignition units seem to be set identically and would of thought they would have been different possibly or maybe not ?

 

[650Skull]

I'm thinking it hasn't been rephrased as the electronic ignition units seem to be set identically and would of thought they would have been different possibly or maybe not ?

Plural???????.

Maybe some pics and/or all the info would help.

 

[007sparky]

Skull I suppose if I take out both spark plugs and gauge their positions as is they should be the same if not phased ? With a dipstick of some sort like myself lol

 

[007sparky]

Ok Skull it seems I'm a lucky boy , after taking out the plugs and using dip test the pistons are out by over 2 inches ! ! Also can visually see when one is at TDC the other clearly isn't , please see photos of dip tube and ignition system , not sure if its a good one or not but its battery free I know that .

P.s. I gather this will have more poke then this engine ?

P.p.s how do I get photos onto here as can't copy and paste ?

 

[Nailbomb]

I had to get my photobucket going to copy pic links.
Upload the pics on another site, copy the pics URL by right clicking it and selecting that, then when posting there is a portrait looking button above the text block. Click that and paste the URL in.

 

[007sparky]

Cheers nail bomber

 

[007sparky]

 

[Nailbomb]

that'll work but try putting [ IMG] before the URL and [ /IMG] at the end without the space I just added there. should make it visible in the forum without opening the links.

Never seen a ignition like that, but if the pistons are out that far its looking pretty solid its been rephased. If its running with that setup, I wouldn't mess with it.

 

[weekendrider]

007sparky, your ignitions are from
http://www.vape.cz/en/

re: pics, In the advanced reply scroll below the text box to "manage attachments".
You can add photos from your system there. These will be the thumbnail pictures that expand when clicked. And will show only at the bottom of the post. The number of photos you can add seems to be unlimited.
Once uploaded they clear the "browse to add" so you can just keep adding photos.
HOWEVER if the pics are large resolution you will do better to upload one at a time.
4-5 large photos uploaded at once seems to clog the software.
Another option would be to upload them to your album on the site. These can be inserted anywhere in the text and will show full size.

I've used your pics to illustrate.
This is from my album

And this is using the manage attachments in the advanced reply.
Hope it helps.

 

[007sparky]

Nice one weekend rider , will give it a go

 

[XSLeo]

When you are writing a post you will see a Go Advanced button. This takes you to a place to do advanced things, like add smileys.
There you will find a Manage attachments button. This leads you to a bunch of Browser buttons, these lead you to your computer. Just find and select the pics you want. Below the browse buttons is a list of maximum sizes for different pic formats. Resize to match these maximums and they will upload.
That's how I do it. Every time I try to use an online pic place I just lose the pics.
Leo

 

[007sparky]

Cheers Leo , I'm working from an iphone maybe that's why I'm struggling lol

 

[XSLeo]

Need a big magnifying glass to use one of those don't you? I always laugh at people trying to do online stuff with such a tiny screen, as well as no storage space. To each their own I guess.
Leo

 

[ANLAF]

007sparky, check out YouTube rephased XS650 videos. On one of them Hugh explains what's happening, and it shows the difference in pistons rising and falling. Ideally a rephased engine offsets the pistons at 270 degrees, but difficult on the XS crank to get beyond 277 because stuff needs cutting. Ignition? never seen that set-up, but as Nailbomb says: 'If it ain't broke don't mend it!'

ANLAF

 

[fredintoon]

- - - can't understand why the engine was designed to have both pistons in alignment anyhow ? Obvious to me that it would rattle like mad

Hi Sparky,
why a 360º twin? Like the song in "Fiddler on the Roof" sez, Tradition - - -
Folks have been trying to make a better Triumph ever since Turner's late 1930s Speed Twin.
Pro:- it's cheaper to build like that and has an evenly spaced firing order.
Con:- balancewise it's just a big single and the only way to balance one of those is with a balancer shaft; add one of those and there goes the budget.
OTOH a 270º parallel twin ( or 277º on an XS650 because that's as close as it gets with a 13 spline center shaft) is closer to being balanced and so vibrates far less, 40% reduction is claimed.
Rephased XS650s run smoother so they'll rev higher without shaking your fillings loose but "more poke?" Not really. Nicer smoother poke? Oh yes.
Thing is, most rephase conversions also include a 750cc upsize and a hotter cam grind and that's what gives the extra power.
BTW, lucky you to accidentally find a rephase.
To get your XS650 engine professionally rephased in the USA will cost ~US$3,000 plus shipping.

 

[650Skull]

These links from xs650.org.au will give you all the information regarding re-phasing 277 and 270 degree cranks.

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