Bogging off idle

[JZ05220r]

For those who followed the last thread im continuing this on another thread as I was getting alittle off topic on my other one. In 1st, 2nd gear etc. I am getting a bog yanking the throttle off idle, and it will do it if I twist 1/4, 1/2, and wot, especially when I twist it quickly. I have tried the DEK needle on the 2nd, 3rd and 4th from top. I also tried the 40 and 42 pilot no change, it felt overly rich with the 42 and needle on 3rd and 4th. I’m thinking the low vacuum at low rpm/higher throttle position (1/4 -WOT) is not finding a good source of fuel. I’m wondering if I should get a needle with a smaller diameter, more taper or maybe a short length as well. Maybe a DEJ (smaller diameter than DEK), EEK (more taper than DEK) or DDK ( less length than DEK). Maybe those might help the engine suck more fuel at low rpm high load (rpm) demands. Does that sound like it could help?

[DonnyV]

You have a RB carb right? I would email him and talk with him. Maybe the other mods you have done need different settings with the carb. I would also stop trying to change to many things at once and follow the jetting guide. Do you still have the original carb? It definitely sounds like pilot circuit to me. Just my thoughts

[JZ05220r]

You have a RB carb right? I would email him and talk with him. Maybe the other mods you have done need different settings with the carb. I would also stop trying to change to many things at once and follow the jetting guide. Do you still have the original carb? It definitely sounds like pilot circuit to me. Just my thoughts

Yes but I got it secondhand. I don’t want to bug him although I did have some other work done by him. Maybe I’ll shoot him a message. Thanks

[Molly's 70]

Why did the last owner get rid of the carb? Are you sure it's not worn out and needs replaced? I have all the same mods on my 220 and it runs awesome. I would do a leak down test first.

[JZ05220r]

Why did the last owner get rid of the carb? Are you sure it's not worn out and needs replaced? I have all the same mods on my 220 and it runs awesome. I would do a leak down test first.

I have done a leak down test. It was in good shape. Lost 1psi in 8 minutes. And I don’t see what could be worn out besides the slide and slide bore of the carb. I already put on a new #7 slide just like the RB comes with. Since you have similar mods I’m curious, what happens when your walking the bike at idle rpm in first gear and suddenly quickly wacking the throttle open to 1/2-WOT?

[Molly's 70]

My bike has zero bog anywhere. I can "wack" the throttle open w/o any hesitation.
I'm assuming your jet block gasket is good?
I have a 38 pilot, 152 main, CEK in the middle clip position. I am still a tad rich.

[JZ05220r]

My bike has zero bog anywhere. I can "wack" the throttle open w/o any hesitation.
I'm assuming your jet block gasket is good?
I have a 38 pilot, 152 main, CEK in the middle clip position. I am still a tad rich.

I just replaced it. I think everything fell into the right place when I installed. It was alittle tricky getting it to line up.

[JZ05220r]

I took it out today. I quickly swapped the dek needle with the cek needle. It really wants to get on the pipe, especially with the cek needle. It can be daunting because it doesn’t have the most broad roll on feel to it if that makes any sense. It feels like it wants to either lug or rip through the gears. Overall the feel I’m getting is it’s just not as 4 stroke like as it should be. I just need to be able to roll on the throttle slowly without it feeling like it wants to be revved out like crazy. As for the bog it really isn’t that bad, it’s just when I am on verge of stalling and then mash the throttle, I can get it to happen.

[KDXGarage]

Can you post a riding video if you have a GoPro or similar and Youtube? Maybe you are expecting it to be smoother than it really normally is.

Check out some Youtube videos, such as those from SS109 (admin here) on his Youtube channel. Maybe you can listen to what his is doing and compare your own or point out a part and comment here.

[John_S]

Check out this video about the pilot and air screw. The full throttle test I’m talking about is the same as this but I’m doing it in first gear which exaggerates it more than just being on the kickstand. It’s really important to rip on it like he says to clear it out before doing the test. Once you have it jetted right you can ride a gear or two higher and not have it wanting to get on the pipe so quick. That’s a great suggestion KDXGarage about either videoing your bike or watch SS’s videos. The sound of his bike is what you’re shooting for.

[JZ05220r]

Can you post a riding video if you have a GoPro or similar and Youtube? Maybe you are expecting it to be smoother than it really normally is.

Check out some Youtube videos, such as those from SS109 (admin here) on his Youtube channel. Maybe you can listen to what his is doing and compare your own or point out a part and comment here.

Yes I have one loading on YouTube. It’s taking forever but I’ll post it when it’s done.

[JZ05220r]

Check out this video about the pilot and air screw. The full throttle test I’m talking about is the same as this but I’m doing it in first gear which exaggerates it more than just being on the kickstand. It’s really important to rip on it like he says to clear it out before doing the test. Once you have it jetted right you can ride a gear or two higher and not have it wanting to get on the pipe so quick. That’s a great suggestion KDXGarage about either videoing your bike or watch SS’s videos. The sound of his bike is what you’re shooting for.

[JZ05220r]

I’ll take a look at that, thank you. A video is coming soon

[JZ05220r]

Can you post a riding video if you have a GoPro or similar and Youtube? Maybe you are expecting it to be smoother than it really normally is.

Check out some Youtube videos, such as those from SS109 (admin here) on his Youtube channel. Maybe you can listen to what his is doing and compare your own or point out a part and comment here.

Yes I have one loading on YouTube. It’s taking forever but I’ll post it when it’s done. Thank you

[JZ05220r]

I didn’t capture the bog on video but you’ll have to believe me until I get a clip of that. If you have followed some of my older posts where the bike was basically running rough and sounding weird all the time, I captured that sound. After resealing the pipe and polishing the needle seat it doesn’t happen nearly as much but, It still happens after getting off the pipe and when I get back on the pipe after. It runs rough simultaneously with this weird exhaust note. You can hear it at 26 seconds on decel and 46 seconds in between shifts. I have to admit that it does seem fine in the video but I really am tailoring my riding to deal with the way I described in my last post here. Does this sound familiar to anyone. As for the sound I know it’s not normal based on the way the engine feels when it happens. Also, i know I shouldn’t have been wearing shoes lol... I was just doing some testing in the field. Thanks. Video link:

[John_S]

Thank you for posting that. 26 and 46 sound lean on the pilot. 152 you hear a quick lean bog when you hit the gas. 235-238 sound lean on the pilot. 249 you hear a very distinct lean needle sound and then the last 10 seconds also has that lean needle sound like it’s one clip setting too high. Even when it’s accelerating good it sounds too zingy and that’s a tell tale sign that it’s lean. It should sound deeper in the midrange. I would think running like this had your plug looking hot and the porcelain white.

Put the needle clip one position lower than it is in this video and then ONLY concentrate on the pilot and air screw until it’s dialed in. The pilot is as easy as he made it sound in that video I posted. Lean bog in neutral? Richen the air screw until it no longer does that. Then take it out for the full throttle 1st gear lean bog test also richening the air screw (try 1/8 turn at a time). Once it no longer bogs… how far is the air screw turned out? That’s tells you if your pilot jet is the right size or not.

Like I mentioned in one of the other posts. Recently with the #7 slide I had to go to 1/4 turn out from fully closed before it wouldn’t lean bog. Went up one size on the pilot and then it was 3/4 turns out. Anything more than that bogged. Went 2 more sizes up on the pilot and now its at 1 1/4 and doesn’t bog, but 1 1/2 does, and 1 turn out reacts pretty well but idles too low. It takes patience but once you get it there, you don’t have to mess with it much at all. Maybe 1/4 turn here or there based on big temperature or altitude changes.

[JZ05220r]

Ok I’ll bump up the needle. I also have a CEJ needle coming . As far as the lean noise I was never able to get rid of from a 38 to 42 pilot.

[JZ05220r]

I’m getting angry now. I can’t help it. My trans level has went all the way from the top of the sight glass to below the bottom line in 5 hours. I had noticed it appearing to go down early on but with my faith in Jeff Fredette I chalked it up to the trans oil being “stuck” in another area. Now I am beginning to believe that’s not true. He rebuilt the engine 11 hours ago. He tried to convince me that my crank was in good shape on the phone but I told him to split the cases and freshen everything up regardless. It shows the seals on the receipt but I’m really wondering if he ever actually did the work sadly. Could this explain all the problems I have been having? Idle issues, jetting issues and to be honest it doesn’t smell like just premix being burnt rather a mix of premix and trans oil. I have probably but 40 hours in trying to get it running correctly.

[SS109]

Yes, that very well would cause running issues. The only easy way to know for sure would be to do a leak down test.

Honestly, I would not doubt Jeff Fredette. If he said he did the work then he did it but that's me trusting his reputation. That said, sometimes crap happens. Defective seal, bad spot on the crank, somehow damaged the seal on installation, etc. Now, if you gotta split the cases again, and the crank seals are not brand new when he said he replaced them, then there would be an issue to pick with Jeff.

[JZ05220r]

The weird thing is the leakdown test results were pretty good. I haven’t questioned the work this whole time. I can tell that the crankcase bolt heads were actually moved on the clutch side based on picture I took before removing the engine so I’m thinking maybe the seals were forgotten or prematurely damaged.