21 replies to this topic

[Lee Harris]

After reading Glenns rave review of the Classic trial OKO setup on his 240, I took my old pwk 28 keihin from a 300 raga out and put it on my 340.

I made an adapter ring out of alu first and fitted the std airhose. The main jet was 130 and the pilot 30. The bike would only run if the pilot jet was nearly fully screwed in, ie no air. The jet was too small. I then went to 36 which allowed it to run but the screw was max 1/2 turn out. More than that and it would die when revved off idle. The main jet was too small at 130 so I went to 150 which was too rich...it would not rev out and chocked up. It is now on 38 pilot and 138 main but still is not perfect.

My biggest problem is not the jetting but the total performance. Whilst the jetting needs refining, the carb shows a a problem when hitting steps or dropping the sumpguard on to stones or rocks. In either case, it weakens off very badly, in some cases it will gag and need a second or too to pickup. In others it will cut out, but immediatly restart on the next kick.

I have heard of some problems of the float catching on the overfow tube etc. Anyone point me in the right direction?
Lee

Edited by Lee Harris, 14 June 2008 - 02:13 PM.

[spud]

Lee Harris, on Jun 14 2008, 03:11 PM, said:

After reading Glenns rave review of the Classic trial OKO setup on his 240, I took my old pwk 28 keihin from a 300 raga out and put it on my 340.

I made an adapter ring out of alu first and fitted the std airhose. The main jet was 130 and the pilot 30. The bike would only run if the pilot jet was nearly fully screwed in, ie no air. The jet was too small. I then went to 36 which allowed it to run but the screw was max 1/2 turn out. More than that and it would die when revved off idle. The main jet was too small at 130 so I went to 150 which was too rich...it would not rev out and chocked up. It is now on 38 pilot and 138 main but still is not perfect.

My biggest problem is not the jetting but the total performance. Whilst the jetting needs refining, the carb shows a a problem when hitting steps or dropping the sumpguard on to stones or rocks. In either case, it weakens off very badly, in some cases it will gag and need a second or too to pickup. In others it will cut out, but immediatly restart on the next kick.

I have heard of some problems of the float catching on the overfow tube etc. Anyone point me in the right direction?
Lee

Hello Lee, I've a OKO 26mm fitted to my 240 and its great. All i had to do was plug and play (so to speak) i've not altered any of the settings/jetting nor moved the needle. What the bike ran like before i fitted is hard to say as she ran very bad and was a pig to start. I had my first trial on her last week and won the novice/twinshock class beating all the modern, twinshocks and pre67 bikes. The bike also runs standard gearing. I did try nearly all of the intermediate sections at the end of the trial and could have rode them and had a good result! The carb was great and some guys i know had a quick spin and thought the bike was very competitive. I even had a go on an expert section!!... although i couldn't get the rear wheel to hook up and hop 180degrees, other than that it actual rode the section and even on my rev 3 i would have been up against it.......what i'm saying mate is the oko 26mm works great and is worth £100. The power is smooth low down and bites when i give the beans. On a slighty different note the rear shocks had know gas in them (AA rode the forest trial with out a complaint what man he is) But i did notice the rebound was like a pogo and they are 20mm shorter on the standard items, a new set are on order but i'm going to have the old ones rebuilt.

[axulsuv]

Hi Lee , busy week ,back to work and all... The problem I had with my OKO was the float would hang up due to the float ears being bent just a tad and contacting the float stand . and I probably caused the bend while trying to set the float level ! Only to find a microscopic flaw in the float valve rubber tip that never let it seat correctly ... Chris does do some extensive mods to the slow circuit , but not having a stock one to compare I can't even guess what he has changed ! If the carb worked ok on the gasgas , It may be the differance in intake velocity between a piston port vs. a reedvalve engine ? Or the 28 may be a bit to large in dia. and not be able to develop the required vac. to draw fuel properly at low revs ???
Here is the best kehin info I've found ! http://www.carbparts.com/keihin/needles_tu...g_your_carb.htm
Hope you get the fanny to work , cause the change in mine was like a fresh latemodel engine had been installed !
Best of luck !
Glenn

[Lee Harris]

Thanks for the info. I put the std dellorto back on and the bike runs fine so I will look at the float.

@spud. Did you fitt modded beta pegs to the 240 yet? Can yer post a detailed piccies or two?
thx
leee

[spud]

Lee Harris, on Jun 16 2008, 11:18 AM, said:

Thanks for the info. I put the std dellorto back on and the bike runs fine so I will look at the float.

@spud. Did you fitt modded beta pegs to the 240 yet? Can yer post a detailed piccies or two?
thx
leee

The original pegs still fit, photo's were taken after win......next win will be a centre level when the new shocks arrive.....but the big test comes this weekend with the centre team trial. This event has experts of british national level riding one route which i'll be riding. The course will be a good intermediate centre level so the experts should go clean. i want to shame as many guys on modern bikes as i can .....competitive i can and will be! .....i rode my rev3 on sunday at a club event and hand on heart the fantic is helping me with my riding the beta with balance and hopping, both require a little more effert on the Fantic (not a lot) but this little extra effort is rewarding me. I've got my original carb for the Fantic but its definately not going back on the bike.

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Edited by spud, 16 June 2008 - 08:08 PM.

[furse]

I had similar problem on a rev3 a few years ago, fuel was sloshed around bowl and missed going where it needs to jets, solved by having a extra deep drain plug made, is angle of the carb same as on gasser?

[Lee Harris]

Hi Furse, I think youve got it. The bike is a 240, the engine is from a 303 and the exhaust is a 300. The lack of space means that I needed a 240 inlet stub (small dia) with the std dellorto. As the pwk ius slimmer, I fitted a 301 inlet and the carby is angled slightly to the left to avoid the 300 exhaust pipe. The float is ok, not catching and set right, but the angle to the side might be causing the problem.

I need to moddify the exhaust slightly...where is my ball pane hammer!!!!

Edited by Lee Harris, 18 June 2008 - 11:25 AM.

[axulsuv]

Lee isn't it ballpean hammer ? or in your fanny's case ballpain !? lol !
Glenn

[axulsuv]

And Spud , I remember you asking " fantic , What is it ? "
They kinda grow on ya , Don't they ?
Glenn

[Lee Harris]

Not sure about the pean, pane or pain. but remember Glenn, remember my english is not to bad for a Geeerman! Yours is ok as well for a yankie!!!!

[spud]

axulsuv, on Jun 20 2008, 12:36 AM, said:

And Spud , I remember you asking " fantic , What is it ? "
They kinda grow on ya , Don't they ?
Glenn

Defo, and what a great bunch of enthusiasts you and many other guys are. You won't beleive how cheesed off i'm with my 07 Beta Rev3 i've a major problem in the form of crack between the sub-frame petrol tank. petrol is leaking from the bike and it wasn't caused by a major accident, more the bike fell over. My main bike and trials are still modern sections but the beta may be evicted from the happy family in its place a scorpa sy 2t is looking to become a new family member. Did i mention the 240 has just been fitted with a set of sexy Trik Shox's. Top of the range i might add and what an improvement from the old falcons (no gas in the falcons). I've taken the fast action throttle of the beta just to see what its like ride this Sunday. suspension on the fantic is first class, power is excellent, brakes ummmmm dog poo.

Edited by spud, 20 June 2008 - 08:07 PM.

[axulsuv]

Spud ; How do you like the ride of the trikshox's ? Do the heim joint mounts free up the movement so the shocks don't bind in the mounts ? (major cause of shock failure ...) Because I'm thinking of another set of slightly longer falcons built w/out eye bushings ... I've found a brg. supply house here that makes a composite spherical brg. that will fit the shock mount eyes . And I've got one of Chris's drilled swingarm shafts
(greasable) here and some self contained/sealed needle brgs that are the same length as the slick long bushings Chris supplied me with for the greasable shaft ... Might have to get the dampening a bit heavier on the falcons , but I think it should work sweet . Just trying to eliminate any binding in the whole setup and to let the shocks actually control all movement . And I think your just spoiled by disc brakes ! I must be getting old , as I've only had disc brakes on street bikes !!! And as far as drums go , they don't get much better than correctly setup fantic/swm hubs !
And Lee , I was just teasing , But you know that ...
Glenn

[Steve Fracy]

As stated on here before, the brakes on my 300 are way better than my old 240. I can easily lock up the front in my driveway and do a nose wheelie as good as my Sherco. What have you guys done with front fork springs.....

[axulsuv]

Wes Variable Rate from Bob @ B&J racing in TN. , He also builds FALCON shocks to your needs ...
And a pretty cool guy too !
Glenn
OOPS , I meant progressive springs :-)

Edited by axulsuv, 21 June 2008 - 03:41 PM.

[spud]

axulsuv, on Jun 21 2008, 01:32 PM, said:

Spud ; How do you like the ride of the trikshox's ? Do the heim joint mounts free up the movement so the shocks don't bind in the mounts ? (major cause of shock failure ...) Because I'm thinking of another set of slightly longer falcons built w/out eye bushings ... I've found a brg. supply house here that makes a composite spherical brg. that will fit the shock mount eyes . And I've got one of Chris's drilled swingarm shafts
(greasable) here and some self contained/sealed needle brgs that are the same length as the slick long bushings Chris supplied me with for the greasable shaft ... Might have to get the dampening a bit heavier on the falcons , but I think it should work sweet . Just trying to eliminate any binding in the whole setup and to let the shocks actually control all movement . And I think your just spoiled by disc brakes ! I must be getting old , as I've only had disc brakes on street bikes !!! And as far as drums go , they don't get much better than correctly setup fantic/swm hubs !
And Lee , I was just teasing , But you know that ...
Glenn

I can't say i've looked at the mounts, yes they do pivot but would need a massive side hop to move them once they've settled i guess. (not sure what brg means). Tomorrow the Fantic will be ridden in anger at a centre trial, one route for the whole event, fingers crossed i do well. The sections will be challenging and the Fantic needs to be in tip top condition the Trik Shox's have made a noticeable improvement they will improve my result. Details of how the new shock's work, design i really don't know how to answer i'm not technically minded, but what i can say is riding the bike on my drive they have transformed the backend from a saggy spring (i'm 14.5 stone) to a nicely damped rear with a lot of travel. My old Falcons were atleast 10 years old and the bike was not on a centre stand when i bought they were also set on max adjustment.... I'm sure a new set of Falcon's would be tops for you and me - visually the Trik Shox's work on the bike and so far are a massive improvment.

The beta went into my local dealer this morning and i've decided to splash the cash on a new 08 Scorpa SY250R. Gas Gas's do not suit my riding style, nor do the Sherco's. Beta and Scorpa and very similar and no offence to Beta if not happy with the cracked frame its a crap design. I've owned a new 03 Scorpa SY250R and it was a brilliant bike then the new one appears to have improved a reasonable amount since 2003, so i'm expecting a very good, reliable, well built scorpa.....and my 03 scorpa progressed my riding by a noticable amount.

I must get along to classic trial, the second week in July i'm working at a club event as an official (blast) but its only once a year. At the end of the month i'm on call so thats another week lost. May have to take a few days off work when the scorpa arrives.....Guy's any events after the second weekend of july which are twinshock you'd recommend i'm all ears.

Edited by spud, 21 June 2008 - 06:22 PM.