xs840/880

papsck · New Member Joined: Sep 30, 2008 Posts: 5

Hi everyone,have a motocross sidecar outfit with a xs motor in it,at the moment it is a badly done low compression 750 using xv 750 v twin pistons and is to slow.Has anyone got the parts to make a 840/880 they want to sell?Also a single carb manifold?
I am in the south of uk phone 01483850024 home.Paul

xs1961 · Posted: September 30, 2008, 7:08 pm Post subject: Re: xs840/880

Paul,I wouldnt bother with the 840 (even less the 880)
Ive owned/built several 840's and even though its a great performer the time/effort/cost just isnt worth it these days..For instance the SP370 pistons cost a bomb, special split/offset collets need to be made for head/gasket location,the large liners that intrude through the cam-tunnel & need to be carefully installed & then youll lose the airflow between the cylinders(so an oil cooler needed), head-gaskets are unobtainable since Tony Hall at HALCO topped himself (he ordered them made in decent enough numbers to make it worthwhile to a manufacturer to bother with,copper DOESNT work!)..
Buy Mikes 750 kit from Holland for the 533 crank , performance is just as good at HALF the price & without any of the above issues !
That along with a gas-flowed head & 34mm carbs is just as good..

yamaman · Posted: October 1, 2008, 5:14 pm Post subject: Re: xs840/880

heres the website
www.users.bigpond.net.au/dave650

xs1961 · Posted: October 1, 2008, 5:21 pm Post subject: Re: xs840/880

Dave Rayners stuff is /was very expensive(+ shipping from OZ ! ) , not as cheap as the Suzuki SP370 pistons we use in the 840 which are expensive anyhow!
Theres a lot of work involved (840)machining the crankcases out , altering the cam-chain tensioner, making offset head/barrel collets , and youll be lucky to get the 88mm liners for a reasonable price & then they might not 'fit' the first time - spare barrels reccomended...
y first 840 kit cost me £450 TWELVE years ago , more like £600+ nowdays ! Stick to Wiseco or Mikes kit.. Much less hassle in the long run as everything you need is off the shelf and no work involved (apart from fitting the new liners if opting for the Wiseco kit)

yamaman · Posted: October 1, 2008, 5:31 pm Post subject: Re: xs840/880

$180 ea pistons, $200 liners and $45 head gasket = $605 to suit 533 or 447 motors =270 pounds stirling or $477 US
Sorry +AU$45 base gasket. This plus shipping has got to be a good deal!

xs1961 · Posted: October 1, 2008, 5:35 pm Post subject: Re: xs840/880

Whats that for mate - 750?

yamaman · Posted: October 1, 2008, 6:04 pm Post subject: Re: xs840/880

840cc

xs1961 · Posted: October 1, 2008, 6:26 pm Post subject: Re: xs840/880

Actually thats a good price for the parts but he'd have to think about the cost of shipping+ import duty + VAT = £200 (ish) .. installing/boring the liners (approx £100) crankcase mods (approx £100)

xs1961 · Posted: October 2, 2008, 3:43 am Post subject: Re: xs840/880

All I was saying is that having owned 840's , the time & expense involved really isnt worth the few extra CC's over a 750 ....
in my opinion performance-wise my 750's (especially with the 533 crank) are as good & at half the price too !

papsck · New Member Joined: Sep 30, 2008 Posts: 5

Thanks guys for info,in talks with Daves 840 parts and sounds best option for me,if i go this way and import from aus is any one else interested in the uk.Paul

xs1961 · Posted: October 2, 2008, 5:53 am Post subject: Re: xs840/880

Ah !
Sorry Paul , I thought you were converting an old motocross/grasstrack bike back for road use ! Embarassed

In that case , youre into racing then 840 is the better option - loadsa torque...I guess for anyone who can actually afford to race these days the extra ££'s for the 840 wouldnt be an issue then..... .Be sure to purchase 3 or 4 of everything though ...

cheers Skull Wink

papsck · New Member Joined: Sep 30, 2008 Posts: 5

Sent Dave a email last wednesday about 840 kit ,had no reply yet,is this normal?Paul Shocked

xs1961 · Posted: October 6, 2008, 12:13 pm Post subject: Re: xs840/880

Took him a week to get back to me once then had a flurry of correspondence from him, he was always keen to help..

What Happened to 650rider.com?

Yamaha xs650