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newnewmember

air cooled mono hunting @ tickover when warm

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Hi, I am having some issues setting up this air cooled mono, its recently had a full engine rebuild, I have cleaned out all the exhaust system and repacked it, i have had barrel off for inspection and this would appear to be correct, i have stripped the carb down and to be honest its very clean(original 26mm TK), it would run then suddenly stop...this faulted to the ht secondary ...replaced aok, i rode it 3/4 throttle up a long hill and then did a plug chop)nicebrown/tan colour(, the problem is lower down in carburation especially when warmed up, i believe the pilot maybe a tad weak, anyhow iset air screw to 2 out, and rode it around fine tuning on air and tickover then it started to  hunt at tickover and take a little while to settle down after revving, its also had reeds checked and they are spot on no daylight on either set/no damage, from 1/4 throttle it feels fresh and will pick front up no problem 1/2/3 gear.......it maybe how these bikes are i dont know ive never had one before.I havent checked timing, its got a new ht coil new ngk plug capnew ngk5 plug, its not drawing air in everything tight, air filter  been cleaned and re-oiled(lightly)........?

Im thinking a  dodgy crank seal cant be after rebuild 30 hours ago(i.e. before i had it)

Edited by newnewmember

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Certainly sounds like an air leak, have you sprayed it while running ?  If its the ignition side crank seal, there will more than likely be some 2 stroke residue in the casing.

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history, when i went to see bike..it started second kick....but seemed rich off the bottom but sounded OK, got it home and air screw was 1/2 turn out from full in, so i looked up what it should be and backed it out to 2 turns improved things greatly....then it would randomly cut out(traced to faulty ht coil this was replaced and resolved this issue), cleaned and repacked exhaust and checked carb(spotless inside) running a 42 pilot middle clip and 140 main,  had a look again today got it warmed up, then it started again when warm, at 2 turns(iy took about 6 kicks to sart from cold/no check/warm day) so wound the slow screw out to 4 and speeds up and when revved takes longer to get back down,  so slowly turned it back in and surprise suprise ended back to 1/2 a turn out, now it feels slightly rich off bottom but its very slight and  the surging dissapears, so i tried an extra 1/4  out and the surging starts to re-appear......this points to a richer slow jet needed.next step 45?? or a custom file out of 42?? hmm  or could it just be the the richening of the pilot cct is masking a very slight main/engine air leak?  I will do a leak test next before changing slow/pilot jet.......!

Edited by newnewmember
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Hello mate, I have had the problem of bike running rich off the pilot for some years now... I didn't realize how bad it was until I tried a different carb off my mates bike runs perfect all the way through rev range.
I have tried pilots from size 36-42 with no joy. I have tried the Kihien flat slide but a pain to set up so put Tk back on.. If you want to send me a pm with your number I will gladly pass on some of what I have tried.👍

 

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1 hour ago, slack said:

Hello mate, I have had the problem of bike running rich off the pilot for some years now... I didn't realize how bad it was until I tried a different carb off my mates bike runs perfect all the way through rev range.
I have tried pilots from size 36-42 with no joy. I have tried the Kihien flat slide but a pain to set up so put Tk back on.. If you want to send me a pm with your number I will gladly pass on some of what I have tried.👍

 

Hi, im asuming you put a new 26mm TK carb on ? 

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On 8/3/2019 at 3:03 PM, b40rt said:

Certainly sounds like an air leak, have you sprayed it while running ?  If its the ignition side crank seal, there will more than likely be some 2 stroke residue in the casing.

Took flywheel of  and plate yesterday, seal looks mint no signs of leakage or residue, also took clutch side off that seal LOOKS fine  but I will still leak test to tick that area off

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 250`s ran good, 350`s not as well. When the rebuild was done, was the mid pipe repacked or at least burned out? I assume new main bearings with the rebuild.

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22 hours ago, newnewmember said:

Hi, im asuming you put a new 26mm TK carb on ? 

No... the carb I tried was off a used pinky couldn't believe the difference in performance. What we have realised after getting the barrel rebored with Wossner piston the port timing was wrong.

I have had to put two base gaskets on to compensate for this?? Also two of my mates have had to do the same..

I

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18 hours ago, lineaway said:

 250`s ran good, 350`s not as well. When the rebuild was done, was the mid pipe repacked or at least burned out? I assume new main bearings with the rebuild.

I have just done the the exhaust and repacked it, all mains conrod piston kit  wossner seals gaskets etc done 30 hours ago,  the pistoni is 8180DA I think this may make  263(dont know), the bottom end although a tad rich does pick the front up no probs in 1st four gears, its just the tickover issue when warm 

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1 hour ago, slack said:

No... the carb I tried was off a used pinky couldn't believe the difference in performance. What we have realised after getting the barrel rebored with Wossner piston the port timing was wrong.

I have had to put two base gaskets on to compensate for this?? Also two of my mates have had to do the same..

I

Hi, which piston part number?

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Update, leak test.... issue found around reed housing, cleaned and re sealed now ok, I now am able to back pilot out another 1/2 turn and this is the best setting for how the bike is with the TK carb, I let it cool down 2 hours later, then try to start it 8 kicks later starts runs fine, not happy with this, so  I have now fit the  OKO 26mm with similiar jetting to TK, its running  but TOO rich, however it is starting 1 st kick now...just need some time to dial it in 🙂

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Pass? If you put the wossnor pistons and standard piston together (using the gugeon pin) the wossnor piston has a taller crown..

 

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3 minutes ago, newnewmember said:

Update, leak test.... issue found around reed housing, cleaned and re sealed now ok, I now am able to back pilot out another 1/2 turn and this is the best setting for how the bike is with the TK carb, I let it cool down 2 hours later, then try to start it 8 kicks later starts runs fine, not happy with this, so  I have now fit the  OKO 26mm with similiar jetting to TK, its running  but TOO rich, however it is starting 1 st kick now...just need some time to dial it in 🙂

I will be at Buttsfield this Sunday as the northern classics has been cancelled if you want to have a bit crack.

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5 minutes ago, slack said:

I will be at Buttsfield this Sunday as the northern classics has been cancelled if you want to have a bit crack.

So the wossners alter the Squish,/compression,  i only know what ive seen on this bike, cheers 

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