Happy new year ,and the suns out

fred · Post by **fred** » Tue Sep 04, 2012 9:46 pm

just the tank to paint now and bleed front brakes

cheers for all the help,ive learned loads and wont stop now yer never stop learning,cheers again

teerex · Post by **teerex** » Tue Sep 04, 2012 10:06 pm

Looks nice that Fred.

fred · Post by **fred** » Tue Sep 04, 2012 10:16 pm

shame the lad did the seat hump the way he did ,but at 180 deliverd i couldnt grumble and he just took over from his dad who passed away,only unwrapped it today ,need to put some heat tape in the bellypan ,got a roll we use on the graindryers, built as a usable road bike thats easy to clean,i can live with pistons n barrels on the list tho ,

dave32 · Post by **dave32** » Tue Sep 04, 2012 11:36 pm

Lookks good well done!

Love the "test run" fuel tank

Any idea what pipes they are?not Nikons,lomas maybe?
Are you gonna add some livery/decals etc or just keep it plain?
whats wrong with the barrels,has the plating started to flake off or are they damaged?
ATB
Dave

fred · Post by **fred** » Wed Sep 05, 2012 4:13 am

nawts wrong with the barrels n pistons ,but they will be consumables ,to mend ect,pipes done em mesen ,have a read ,ive still got blanks to make 2 more full sets(cheers trish for the good side on photos or it may of been the flutes),i can send u the info ,but i aint tested this yet,

ScottaKR · Post by **ScottaKR** » Wed Sep 05, 2012 7:49 am

Lookin good there fred. I'd all but forgoten about that pipe project of yours. Would be cool to see a back to back dyno of them vs stock S pipes.

dave32 · Post by **dave32** » Wed Sep 05, 2012 12:46 pm

Yep i posted then stumbled across the build thread

have you got stock pipes to test back to back?
probably worth getting a selection of jets say from 160 to 140 as youve modded quite alot of the internals.
Did i read that right that you have removed the curve in the stock B exhaust duct?

just ground out the lower section or welded up the top so its straight?
Bit late now but if you do another set of barrels its better to keep the bottom of the liner and use it to direct the intake towards the transfer ducts,cutting it off doesnt reallly accomplish much as its then aimed at the crank.
Cheers
Dave

fred · Post by **fred** » Mon Sep 10, 2012 8:29 pm

i know what you mean about the back skirt but i had to match it to the other barrel ,and had seen it done on these

does anyone recomend what size jets to start with ,standard headers into diy jim lomas coppied expantion chambers 1mm mild steel,flowed crancases ,mesh filter in stock airbox but i can open up 4x12mm holes in the front of the lid,mot this friday.

fred · Post by **fred** » Mon Sep 10, 2012 10:54 pm

i knew it was somewhere i read it years ago ,marks work has been such a benifit to us .jetting charts
http://myweb.tiscali.co.uk/teamsparrow/kr1sjet2.htm

dave32 · Post by **dave32** » Tue Sep 11, 2012 12:21 am

I guess there are 2 ways of looking at it,use the skirt to direct flow towards transfer area or remove part of it so there's a larger catchement area (transfers).
Whats with the mesh instead of filter foam?
i mean you have the full lid,intake is pointing rearwards,your not gonna get stones in there (which is all mesh will stop),but it wont stop small airborn grit/dust etc getting in (which a foam filter would).
If you want the motor to breathe a bit easier then what i do is keep the front half of the lid but run the foam filter (need to upjet with this).
Personally on the jetting front,just start big (160 ) and work down til it feels good then make some plug inspections to confirm its not too weak,then experiment with the needle (again start too rich and work down),once your happy with this you may need to double check the main is still right (one part effects the next),finally you can get the airscrew set to wear you need it (start on 1/2 out from closed).
first rule of jetting,dont copy someone elses even if the motor is a similar spec,there's too many variables to guess what you and your engine need.
when in doubt go rich until it shows signs it is too rich then work back down.
Dont rely on plug readings,there only really useful as a confirmation not for predicting what size to run and you need to know what YOUR plugs look like when its running well.
bear in mind its a road bike,unless you dont mind changing jets every time the weather changes then dont jet for on the limit performace,a change in temp/rad or humidity and its good bye pistons and friends

Still confused about that exhaust port,the stock B2 roof curves up unlike the straight roof (from the port window) of the S so if you grind the floor out it would be a bit big to say the least.

HTH
Dave

fred · Post by **fred** » Tue Sep 11, 2012 8:57 pm

cheers dave , if i do the plug chops i read about in the late 80`s warm up ,go for a brisk run then try n do say mile n half at 6 grand say in 4th gear (driving easy) then clutch in shut throttle n turn of n coast to a stop , ( i was actually given a producer while i wa doing a plug chop in 1989 other side of leverton hill near retford,microns on a lc125 took performance bikes mag to the cop shop and he photocopied it for the info ,is it pre 85 bikes did`nt need a bs stamp , will order the jets now ,n book mot ,cheers again for all the help =D>

KR-1R · Post by **KR-1R** » Wed Sep 12, 2012 1:50 am

fred wrote:cheers dave , if i do the plug chops i read about in the late 80`s warm up ,go for a brisk run then try n do say mile n half at 6 grand say in 4th gear (driving easy) then clutch in shut throttle n turn of n coast to a stop , ( i was actually given a producer while i wa doing a plug chop in 1989 other side of leverton hill near retford,microns on a lc125 took performance bikes mag to the cop shop and he photocopied it for the info ,is it pre 85 bikes did`nt need a bs stamp , will order the jets now ,n book mot ,cheers again for all the help =D>

^^^ looks like a single malter

dave32 · Post by **dave32** » Wed Sep 12, 2012 11:16 pm

)No worries Fred

Microns,lc 125 that takes me back,i actually had an Allspeed but for a while i ran an short can micron off my brothers 350LC,it didnt fit so was just cable tied at the rear mount

,was always trying mad stuff to get more power

Was great fun though, i had a shelf of pistons that were testament to my efforts,every night was spent with the carb off,different reeds,different carb (i settled on a 35mm keihin off my KX125

).
ahh happy days

My advice for doing plug chops is to ride it around normally and note how it feels,if it feels a bit lean then engage the choke see if it helps (also gives you an idea of what too rich an mixture is if you leave it on)dont do any full throttle top gear runs yet,just get a feel for the motor,if it coughs and splutters but then clears the main is probably too big (it could be the needle though),
Once you know its safe and not running lean (signs are runs good from cold,very clean even when cold,will probably feel responsive in neutral but under load such as a hill will feel flat/gutless) then you can do some short bursts through the gears,say 2nd,3rd and 4th to max revs then whip the clutch in and the kill switch and pull a plug,if its brand new its quite hard to tell,your better off with a decent used plug.
Plug colour depends as much on where you bought your fuel as to what make oil your using,but to generalise the lighter the colour the hotter she's running.
On a roadbike all i use a plug chop for is to confirm its not too lean/over advanced,if it reads a bit dark or sooty then providing it feels good and does what i want i dont worry.
If you search for Eric Gorrs Off Road manual it covers all things that are useful for setting up a 2 stroke,including the "ride and feel" method,pretty sure there's an online version you can download,if i find it i will post it up for you.

ATB
Dave

fred · Post by **fred** » Sat Sep 15, 2012 7:03 pm

sorted gear change today and painted the tank,after running 160 jets yesterday but couldnt try things properly ,changed to 150 `s for a test ,seemed to have fuel starvation probs up the rev range so will pop the 160`s back in and remove the inline filters ,as ive washed the tank out now , so all good apart from cracking my clear screen last thing

dave32 · Post by **dave32** » Mon Sep 17, 2012 5:28 pm

are they genuine keihin jets or RD?
RD flow less,you need around a 150 to flow just slightly more than a genuine 137.5/140.
Better/safer going down one size at a time,160 to 150 is a big step.