Off idle bog in gear not in neutral

[bluespark]

So I've been battling this condition for a while and can't seem to dial it in. It seemed to have started when I changed/cleaned a few things. New reeds (old ones were still in decent shape) , new pipe flange O ring, re-packed muffler and took a torch to the really gummed up perforated inner tail pipe, raised the carb float to level, and lastly installed a Clake Prolever.

I think that it started to run a bit lean, as it was boiling rather easy so I raised the needle a clip and also had a rad cap that tested bad so I replaced it with another 1.8bar.

I'm at the point now where I'm trying to fine tune the air screw but can't seem to find the sweet spot (it ran great for a few years till I made the above alterations). I can get it to where when it's idling in neutral the throttle response is nice and crisp and with it still running if I drop it into gear it's still crisp. But if I leave it in gear and turn the bike off and start it again, the idle rate drops down and the off idle bog seems flat and boggy, which i think indicates a lean condition, but seems to run more poorly if I try to richen it with the air screw.

Could there maybe be more drag on the clutch with the Clake installed causing issues? When I can get the response crisp it seems that I have to have the idle set faster than it used to be. Is there a relation between idle speed and throttle response?

2011 EC 300E
PWK 38
168 main
38 PJ
N3CH needle middle clip
#7 slide

 

[bluespark]

Would the throttle cable free play have any impact on this issue? I checked it out and I have pretty much no freeplay on the throttle cable. The adjusters on both ends of the cable are turned all the way in. I can't say if I ever had any to begin with.

 

[bluespark]

I've noticed that it revs nice in neutral with the idle turned up slightly faster than it used to be, but if i drop it into gear and slowly let out the clutch lever, the idle drops and the bog returns.

 

[motopsycho87]

Have you checked your reeds? You're also more likely to get "bogging" from a rich condition, lean tends to raise the revs and not feel powerful with a "BOOOWAAAAHHHHHH" noise, yours sounds like it may be fluffing? A video would help a lot

 

[bluespark]

https://youtu.be/jaKA2vzAlWg

 

[VilluEST]

It seems to me it's caused by minor clutch drag and you should not worry about it. My bike behaves just like that as well. The engine has significantly less power at lower RPM and thus can't over come the drag. I don't think you will ever ride at such low RPMs and if the bike is moving there should be no problem at all. I think you will just have to learn to live with it since this little clutch drag is impossible to tune out. You can, however, change to different oil: http://www.gasgasrider.org/html/gear_oil_evaluation.html

 

[Zman]

If it bogs with the clutch in, it will very likely bog while riding. From my experience off idle bog is related to being lean. You can tighten / close your idle air screw a 1/4 to 1/2 turn to see if it gets better. If that makes it worse, it is rich and you can open/loosen the idle air screw from the original screw position.

 

[skippyjlo]

Double check the carb boots are on correctly and not letting air past? Or if it is clutch drag try back bleeding the clutch, inspect clutch plates (maybe shuffle some around, could try different oil as mentioned earlier. Hope you get it sorted out

 

[bluespark]

Thanks guys. I sprayed brake cleaner around carb and didn't find any leaks.
I've been using drug store mineral oil in the Clake since I got it. I'll try some proper oil also and see how it goes. Any tips on what to flush it with?

 

[Jakobi]

Its a normal symptom of an engine. At revs that low, when cracking the throttle there isn't enough signal or vacuum to pull the required fuel through to allow the engine to respond.

The FCR carbs on 4 strokes being more complicated use a squirt jet to overcome this issue by directly shooting a jet of fuel down the intake port. The PWK doesn't have this.

You could try richening it via the pilot/air jet and then possibly raising the idle up some more to compensate.

I also agree it's some slight clutch drag pulling the revs back down as you let it out and then re-pull it which is highlighting your symptoms. Do you experience it while actually riding?

 

[bluespark]

.

I also agree it's some slight clutch drag pulling the revs back down as you let it out and then re-pull it which is highlighting your symptoms. Do you experience it while actually riding?

Yes I do. If I'm going up a steep hill in first or second and chop the throttle for a second or two it bogs when I get back on it.

 

[Jakobi]

Yes I do. If I'm going up a steep hill in first or second and chop the throttle for a second or two it bogs when I get back on it.

Some more fuel is what I'd be looking at.

You also mentioned it has run very well for several years prior to this behaviour. Has it ever had a new set of rings, piston, or even spark plug?

 

[bluespark]

Some more fuel is what I'd be looking at.

You also mentioned it has run very well for several years prior to this behaviour. Has it ever had a new set of rings, piston, or even spark plug?

It got new piston and rings about 60 hrs ago. New plug late last summer.

Im going to start digging in tonight and try some ATF in the MC.

Is there a good tutorial on doing the clutch rebuild (if needed!) ?

 

[bluespark]

Problems (overheating, cracked wp impeller, blown wp seal, etc) seemed to start shortly after Clake Prolever install, maybe 40 hours ago. So it's making sense that there could be some clutch issues to work out.

 

[barossi73]

Based on the changes you made in the original post id be trying a p40.if it helps but still bogs,revisit your float level.if the fuel level is set too low it alters the specific gravity (effectively fuel pressure),this will mean a little less fuel gets drawn thru,esp at small openings where the signature is weakest.could also be a contributing factor to overheating.
Bogging is a little vague as it can be used for both rich/lean cond.
Try and establish wether its a rich blubbery bog (gargling/choking),or a lean,flat/thin bwooar where the engine struggles to respond/build revs quickly.snapping the throttle open quickly from low revs should establish this (bike fully warm).