2013 ec250r

[Jakobi]

I had a quick ride on the latest stacks I have. The first revalve was a real stab in the dark. Redesigned the MV, Rebound, and BV. It was modelled off what would work well for a KYB and also compared a bit against the previous stacks. What I did was end up with a 2 stage BV and clamped on (2) 14x.2 shims as opposed to the 11's as stock. This round I left the new MV with its .4mm float, left the 2 stage rebound (bleed removed), and adjusted the BV to have less mid speed comp (after the crossover) and then clamped on smaller shims. Overall the stack is still totally different to the stock one, but around the same total stiffness.

Initial response is great. The clickers are 13,13,and PFP2.5 and the bike feels really good. It sits up in the stroke, doesn't deflect, and soaks up everything to the extent that its hightlighted the shortcomings of the shock! I'm excited about putting in some seat time.

[wence]

Good work mate.
You love delving into things don't ya?
I probably should have played around with the stacks a little but since I'd already paid the money the first time I thought I would leave it for now.
Let us know how it goes after a few rides.
Cheers Mark

[Jakobi]

Current Jetting AS2 40 NEDW#2 175

My 250 is all but jetted to perfection with a smooth pull from bottom to top and nothing more than a brrrr on decel. I'm having a few hiccups with hard starting at times, which I think may be related to the float level. It feels like starting it cold it works better if I let the bowl run down before putting it away, and then starting it with it half empty. Also experiencing some hard starting after laying it over when sampling soil. I'll check the float heights when I pull the shock for a revalve. N_green, what float height did you settle on with yours?

Suspension is broken in well.

Forks are 90% there, but still a high speed spike on sharp edges at speed. I'll be addressing with the MV either through a bit more float or a little less damping. Still deciding. Base valve feels pretty good and the clickers are sitting right around the middle of the range for what I ride, offers better bottoming resistance, and the action through just about everything is great. So much so that I'm not sure if I even really feel the need to go up a spring rate. I think I will and then reduce 25-50cc of oil and let the spring assist mid stroke, and have the air spring come in later to control bottoming. May help with the spike as well (at 350ml currently).

Shock is still on the stock spring and running way too much preload. Pretty happy with the high speed damping (LS comp fully open, rebound 16 out), but the excess preload is causing initial harshness. I need to go up a spring rate and then revalve to address the rest. I'm not sure which direction to go with the valving. Have a few thoughts in mind, but need to do some testing. The crosstalk between the rebound adjuster is the tricky bit.

Other than that the bikes getting smashed up. 50hrs now, and have just about blown out the lower pipe mount. Have a ktm on hand to replace with. P3 pipe guard shows signs of doing its job on the rhs. Plastics have had to be shimmed in places where excess play from vibrations have been working away at it. The tank shows some wear from rubbing against the seat locating tab on the subframe. This has had some rubber glued to it now. The seat itself was getting sloppy on the tank locator and locating tab on subframe. Also fixed. Two piece rad shrouds are a bit loose on one side where one clip has been snapped. And managed to crack both rhs and lhs brush guard mounts, as well as the lhs lighting block. Seat cover has torn down both sides.

Anyone would think I don't look after it

[Jakobi]

Ended up going up to .44kg/mm fork springs with a lower oil level (need to check notes but between 300-325ml). 3mm preload on the springs. Did not feel the need to revalve, but the added support of the spring reduced the front end diving under brakes and any busy feeling. This allowed the comp adjuster to be run out around 17 clicks and give a very nice plush action over roots while still feeling quite firm overall. I'm happy and still had some travel left at the end of the day. No bottoming. Mid range spike seems to be less evident too. Still not sure if its due to sitting up higher and not blowing through the stroke, or running less compression overall. Will likely need to do some repeated testing making adjustments to be sure.

Rear still needs work. On the cards. Stock spring and valving is quite ridable though, just has room for improvement.

Engine wise, at ~50hrs have just pulled the pipe to inspect will report findings later. Spark plug looks good with current jetting so not sure if I'm going to tinker or not. I think some more low end grunt could be had with a half clip richer. Maybe.

The vibrations I had been noticing through the bars appeared to be getting worse, especially after a back to back ride with the old bike. Quick check of the engine mounts showed up the problem. Front one was so loose you could turn it in the frame by hand. The lower not so bad, but still not torqued up to spec. Will address this now as well.

Airbox is OK overall, but still doesn't like water much. The vents on the front side fill it up good. I always take the time to drain the slotted gromet after crossing something substantial, but I have noticed during most muddy rides the drain actually gets blocked up with grit, rocks, and whatever other debris makes its way into it, requiring me to fully remove it and blow it out.

Overall, pretty happy with the bike. I'm thinking while the pipe and coolant is drained I'll do the tranny oil and check the PV tension too. Plans to do a piston and rings in the next 25hrs.

[desertgasser300]

Originally Posted by Jakobi

The vibrations I had been noticing through the bars appeared to be getting worse, especially after a back to back ride with the old bike. Quick check of the engine mounts showed up the problem. Front one was so loose you could turn it in the frame by hand. The lower not so bad, but still not torqued up to spec.

Same thing happened to me. The vibes kept getting worse and I thought maybe it was because I put on the 23oz FWW. Last week while I had my head down to switch the mapping I could see the front engine mount bolt vibrating around in there. A quick tighten back at the truck and all the vibes seemed to disappear. All the other mount where tight. Just a note to anyone having more vibes then usual, check the mounts.

[Jakobi]

Exactly! How did you manage to give it a quick tighten? The flywheel side you might be able to get onto, but the kick starter/water pump side is a really tight fit even with the lower rad hose pulled from the water pump.

One thing I found very interesting was that the bike didn't feel vibey at all. Just the handlebars, and only on decel at a specific part of the rev range.

Powvervalve tension was right on from the factory! Nothing to do here which I am happy about!

Jetting wise I thought it could use some more fuel in the mid, but now that I've identified the source of the 'buzz' as being the engine mounts, and inspected the plug, and the piston dome I'm pretty confident its a touch rich still if anything. Quite a bit of wash around the front side of the piston. The piston itself looks to be in great shape. Still quite a bit of the coating on it, and no blow by evident (from what I can see through the exhuast port. The back side of the cylinder looks like new still. Did a compression test on the engine. I mustn't have taken any notes or done a test after installing the head (once machined), but comparing it against my other known head and what it reads new, and what this engine read stock, and what it reads now everything is looking great with only a few psi down from where I'd expect it to be (on my gauge).

The exterior of the bike looks like an old beaten up slave worker. Battle scars here and there. Dirt and mud in nooks and crannys. Its definitely being ridden.

[n_green]

Originally Posted by Jakobi

Current Jetting AS2 40 NEDW#2 175



My 250 is all but jetted to perfection with a smooth pull from bottom to top and nothing more than a brrrr on decel. I'm having a few hiccups with hard starting at times, which I think may be related to the float level. It feels like starting it cold it works better if I let the bowl run down before putting it away, and then starting it with it half empty. Also experiencing some hard starting after laying it over when sampling soil. I'll check the float heights when I pull the shock for a revalve. N_green, what float height did you settle on with yours?

Sorry Jake didn't see this til now, 99% sure my floats are at 8.5mm. I'm happy with them there it passes the 45 degree test and starts easily all the time.

[n_green]

My PV was also spot on from the factory. Maybe they do take a bit more time on the production line now.
Good tip about the engine mounts, I have noticed mine feels rather vibey through the bars, I'll make sure they are tight. I've already lost one of the small Allen bolts holding the rad shroud onto the tank from vibes and came close to losing the handguard mount bolts.

[Jakobi]

Cheers Nath. I still haven't made any adjustments to mine, but I will drop the fuel level a touch more when I've got the carb out of the bike next. I'll make sure I snap a load of shots when the top end comes down too.

Definitely check the engine mounts, as stated, both of mine weren't tight, but only the front one was loose. I've also lost one of my shroud bolts earlier in the picture. With the force guards watch that you don't mash the row of fins on the radiator with the dicky setup they use. Hopefully they've changed the design since mine. I did give them feedback on it.

These forks are working like magic now too.

[desertgasser300]

I managed to get a 1/4 driver in on the right side on the front mount and a wrench to hold the left side.

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