XR400 Four - Skunkworks Special

just started stripping down an 81 gsx400F that i grabbed for $400 a couple of years ago, the intention is to get it road worthy for a mate to ride on his L's but we'll see what happens (looking at a DR or something similar for more adv type riding soon after) I might have it ready in time to tag along to this (if i can get loki another bike to ride by then)

First thing i noticed when i pulled the sump plug is that fuel's been getting into the oil (stuffed rings i suppose) and i mean a lot of fuel obviously over some time. it's a 2600ml capacity sump and i pulled 7 ltrs of oil/fuel mix out of it....:huh any of you guys who know something about engines got any ideas where i should start with trying to fix it?

Between the tank and sump there is:
fuel tap -- very likely
floats in carbs -- even more likely
1 open valve -- positively likely
2 years to degrade ring seal -- yep
Start at the top.....and enjoy

cheers mate, looks like i've got a bit more work than i'd planned but at least i have some idea what to look for now... :eek1

im gonna need a lot more beer before i start working on it again this weekend

here ya go Pezz - make something like this



or something like this



or you could just do up the XR like this

Powdercoat - Blue

I'm with Carmina, just love street trackers, have done all my life.......only now that style even has a name!

Classic satin black always looks cool, especially when accessorized with a few colour highlights, like a chrome pirate "skull-and-crossbones" (if u c it on a black 640 Kato, say hi ), tasteful red/yellow/white flames, gold-leaf (?!?!?) scallops edged in blue, the possibilities are endless........

Sorry Guys, things are a bit slow as I had a bout of appendicitis and was in Westmead Hospital Last Friday to have them removed. At 46 :huh

Must have used a blunt axe as I am pretty sore at present. Actually they were really good and I have no complaints at all. I however will take a little while to recover, given my other conditions.

I will be back on the work really soon.

OUCH!! :eek1

Only a year behind you, know (sort of) how you feel.

Take it easy man, get better soon.........and don't lie there dreaming up ideas and sending yourself nuts!

Well things have been quiet, Im about to pull the carbies down and the Oil pump and clean up the head.

I will post some pics soon

Cmon cmon cmon! You've been threatening to do this all day! Have you got em cleaned yet? I got the body on the truck like i said i would

All that on your Birthday OldDog . . . . . .

<o:smarttagtype namespaceuri="urn:schemas-microsoft-comffice:smarttags" name="country-region"></o:smarttagtype><o:smarttagtype namespaceuri="urn:schemas-microsoft-comffice:smarttags" name="place"></o:smarttagtype><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <wunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if !mso]><object classid="clsid:38481807-CA0E-42D2-BF39-B33AF135CC4D" id=ieooui></object> <style> st1\:*{behavior:url(#ieooui) } </style> <![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> Well it’s been a while since I updated this thread, so here goes.<o></o>
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I had Odeano and ATGreg over for a cup of tea and a chat to pull the head and barrel off to get bored and overhauled. We didn’t do much but it was good to catch up, Thanks Guys. <o></o>
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The motor looked like this inside<o></o>
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The head looks like it may need a clean<o></o>
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It now looks like this, the valves have been de-carboned and cleaned, just need some valve stem seals and it can go back together.<o></o>
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I have the parts fische for the CB400 Four and looked up some of the parts needed to get the bike built. It was amazing the price difference between here and Overseas. The list mainly made up of Seals, Gaskets and O-rings etc<o></o>
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David Silver Honda in the <st1:country-region w:st="on"><st1lace w:st="on">UK</st1lace></st1:country-region> worked around $280 + freight<o></o>
Service Honda in the USofA worked out $256 + freight<o></o>
Honda Australia worked out $596 <o></o>
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After some sourcing O-rings locally I got the <st1:country-region w:st="on"><st1lace w:st="on">US</st1lace></st1:country-region> order down to $116 Aussie + freight.<o></o>
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It pays to shop around. One o-ring from Honda was $9.75ea from CBC Bearings $0.17ea, when you need 4 it saved me close to $29.00. Another o-ring from Honda was $11.25ea from CBC Bearings $0.30ea, when you need 4 it saved me close to $44.00.<o></o>
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The barrel has been bored and just need to gap the rings and wait for the parts to arrive. I decided to paint the barrel satin black, for heat dissipation. Looks nice too.<o></o>

Pezz...what are you doing mate - you let Deano loose near your bike :huh

Good to hear there's some progress though

Well Im at a bit of a stalemate with the back end of this build . . . .

The front end will be a snack, I want to match the travel, front and rear. The XL steel swing arm is 540mm long. However the top shock mount is way too far back to make it work with what I have in the shed.

In wanted to be sympathetic to the little 'Supersports' and try to make everything reversible. But it just doesn't work the way it is????
If I butcher the frame I will condemn this bike to Off-Road for ever

Probably not the worst fate . . . . but it will take a lot of time to get it right, and I only have 4 weeks to finish the build, with the parcel arriving any day from the UK with the Parts I ordered to finish the engine.

Decisions, decisions.



I have a LC4 sub-frame and seat unit there . . . . Just cut the 400 back end off and bolt on???? . . . . :huh

Welcome to the Asylum Mr Viking

The Banshee shocks will not work unless I move the top shock mount forward.

How about scrounging wreckers for a swingarm off a 750/4K, they're 2.5" longer with the shock mount in the same spot?

Longer arm for better traction and travel, and need longer shocks by about 2" to fit in the gap left over. If it's not long enough, then cut and shut both to make it long enough to suit.

Works on old-school drag-bikes running 2 Dellorto's off an Alfa.......
AH, those were the days!

Thanks Modnrod, if it was a road bike that would be fine, as this is an Off-Road bike the geometry doesnt stack up. I need to get the travel the same front and rear and the XL swingarm is already 100mm longer than the CB one.

Dellorto's mmmm and what was the fuel economy like on that bike

Just won these on Ebay USofA

Twin Ohlins off an old Husky - 500mm between the centers.

That should lift the back up a bit

I think I will still have to butcher the back of the frame to make it all work.

nice score mate...hopefully there in good working order

Mark