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dadmacmx

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About dadmacmx

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  1. dadmacmx

    Mikuni jet block gasket failure

    Funny you should mention that, like for like maybe not the best option long term but it seems JD is hoping to have a repair kit available with jet block gasket, replacement T10-Torx and an o ring with a bit more meat on it for a more appropriate fit
  2. dadmacmx

    Mikuni jet block gasket failure

    Cometic building a replacement gasket apparently testing a 0.014 gasket, JD ordered a bunch for testing it has a steal core and is coated so should not extrude under compression Some on KT cutting their own gasket from 0.4mm base gasket as a quick fix, but there may be a small variation in the recess depth that the gaskets fits so may be worth a measure if you make your own, until cometic is finalized Final thickness of cometic gasket to be confirmed through testing O ring size required for needle seat is, 7.5mm I.D. x 1.53 mm from jetsrus 002-709, Mikuni ref KV/10 Seems the jet block gasket is a different shape on the KTM due to the twin port design of the jet block, but it also appears the 2004 RM125 Mikuni had the same twin port design and has failures too From a post on TT apparently a guy had a hard time jetting his 04 RM125, July 17 and found this when opening her up, surprise surprise the problems been round for a while Thanks enmerdeur from KT for spotting it JD brought up the failure of the o ring causing problems thought it would seem reasonable to bring it up and change it out as some are having both fail at the same time, some had o rings break up being removed so totally knackered And for the sake of an O ring why wouldn't you change it out anyway
  3. Just a heads up in case no one has been over to KT for a while, not seen any posts about it on here The Mikuni jet block gasket on the KTM has been failing some at low hours, squeezed out of position causing erratic running Also the float needle seat o ring has been failing according to JD allowing fuel to bypass this and allow the bowl to overfill even with the float needle closed If you have both conditions at the same time you may be in for one hell of a confusing mess on jetting If yours was running great but now behaving a little weird might be worth a look
  4. dadmacmx

    2015 trax on 2016 KTM!?

    2016 125sx shock setting list Rebound disk 8mm Stroke 140mm Shock length 477mm -------------------------------------------------------------------------- 2015 125sx shock setting list Rebound disk 8mm Stroke 139mm Shock length 490mm Cheers!
  5. dadmacmx

    150sx base gasket

    OK first reply on this forum but here goes and I know its a little late, We have had the pleasure and occasional pain of running several KTM 150`s we started with an 08 Our 13 150 sx stock squish measured 1.23mm on stator side 1.25mm on clutch side, with this clearance the bike was not much fun to ride strong mid aggressive hit very poor top end and very little over rev. The permanent marker from factory on our 13 cylinder stated 1.2 now confirmed by KTM at Dirt bike show that this is the squish as measured by them from factory. However the KTM engineer at show said all the 150 sx should now come with 1.7 to 1.8 marked on cylinder in permanent marker (although KTM would not directly confirm squish should be set at 1.7 - 1.8mm, more of nudge nudge wink wink, as this goes against whats in the manual?), when I said that that puts the piston approx 0.5 - 0.6mm below top of cylinder and not as per dimension X in specs. KTM guy shrugged and said, but its safer that way. Had a look around a few paddocks could not find another 13/14 150 sx with 1.2 marked on cylinder as ours was (however found 125 sx marked with 1.1 and 1.2 on cylinder) Motocross action mag on there 2013 150 sx has 1.8 marked on the cylinder, can be clearly seen in there 2013 125-150 sx shootout. (MXA test 2014 150sx has 1.7 marked up and the 2012 150sx tested has 1.6 on the cylinder) http://motocrossactionmag.com/bike-tests/mxa-two-stroke-shootout-the-2013-ktm-125sx-versus-the-2013-ktm-150sx So tried the new recommended squish setting basically set dimension X to zero (piston level with edge of cylinder) then put on another 0.5mm base gasket and got 1.73mm clearance. made a huge difference in top end over rev and smoothed out the hit (only slightly) but definitely more fun to ride. Makes sense as raising the cylinder 0.5mm advances the port timing, lowers compression and alters the squish velocity. Also had to jet up more revs more heat. After raising the cylinder 0.5mm the exhaust port timing is still not as far advanced as the 07/08 150sx cylinder. The exhaust ports on those cylinders were cast 0.8 mm higher up in the cylinder. The 07/08 is still our favourite cylinder more linear power delivery, similar to the 125 sx, with more top end and over rev compared to later spec cylinders. If you are happy with the performance of your bike especially if its new and never been stripped before and you do not have any issues then measure your piston to cylinder head (squish) clearance using the solder method prior to strip down. . When rebuilding the engine you can remeasure the squish clearance and adjust gasket thickness to achieve the same measurement prior to strip down. The only thing to consider is excessive carbon build up which may affect measurement, our engines are stripped every 10 - 15 hrs so that's never a problem. Always a very good idea before installing gaskets to write on them with permanent marker what the gasket thickness is. Next time you come to a rebuild no need to guess which gaskets were used. From my experience with standard piston/vertex the difference in piston height when changing like with like is negligible, however always best to check. The only time I have had a difference with piston height is when trying a different piston make. Cheers all
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