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Discussion Starter · #1 ·
Ok, so i just got my head and carb back. head was ported/polished and carb bored to 42. i also installed a hotcams stage one. i have open stock air box and modded stock exhaust. so now i'm bogging horribly in 2nd, really bad in 3rd, and then in fourth too. my jetting was JD jet kit 185 main, 45 leak with red needle 4th from top with f/s 1.5 turns out when this happened. so, i went up to a 200 main, needle 5th clip with f/s 2.5 turns out. pretty much same results with even worse throttle response. then the cops got called so we called it a night :lol: .....any thoughts?? am i wrong in thinking it's bogging because it's not getting enough fuel with these new mods? thanks guys!
 

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Ok, so i just got my head and carb back. head was ported/polished and carb bored to 42. i also installed a hotcams stage one. i have open stock air box and modded stock exhaust. so now i'm bogging horribly in 2nd, really bad in 3rd, and then in fourth too. my jetting was JD jet kit 185 main, 45 leak with red needle 4th from top with f/s 1.5 turns out when this happened. so, i went up to a 200 main, needle 5th clip with f/s 2.5 turns out. pretty much same results with even worse throttle response. then the cops got called so we called it a night :lol: .....any thoughts?? am i wrong in thinking it's bogging because it's not getting enough fuel with these new mods? thanks guys!
Please explain "bogging" is it when you first hit the throttle? if you roll on the throttle slowly what happens?
 

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I am pretty sure in most cases when you port and polish and open up the the engine it usually pulls more vacuum from the intake, don't know for sure but I know on the cv carbs the engine pulls more fuel because of added vacuum. Maybe try going leaner on the needle, down a pilot and keep your main the same..correct me if I am wrong guys, I am not positive.
 

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Discussion Starter · #4 ·
Please explain "bogging" is it when you first hit the throttle? if you roll on the throttle slowly what happens?
well, i'll explain but i do think i've gotten it under control after ALL day working on it. But, it was doing most of the bogging through the bottom points of 2nd, 3rd, and 4th gears...LOL, pretty much whenever i had the gas pinned...didn't really matter if i hammered it or rolled into it. but the throttle response at idol seemed ok, i but could tell a slight difference than before i did these mods...nothing that would set off any worry though.

so, basically today i tore back into the head thinking i'd check the timing and valve clearances again. got it to TDC and it actually looked a tooth off so i pulled the chain tensioner and without that slack taken out it looked spot on again (if it was a tooth off, would it have even run though??). so then i just moved on to checking valves...two were tight so i got those back in specs using the 1/6th turn method and i'm pretty sure that was my biggest problem because it ran at about 75-80% better after that. with some re-jetting and the dyno next weekend i should be good to go! any suggestions on jetting would be GREATLY appreciated...i now have a 190 main 45 pilot, screw 2.25 out, needle 5th from top. it still boggs a little in the bottom of 2nd and sometimes 3rd, but it does feel a lot better! yes, that's how bad it was at first. Thanks ranchero.
 

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Discussion Starter · #5 ·
I am pretty sure in most cases when you port and polish and open up the the engine it usually pulls more vacuum from the intake, don't know for sure but I know on the cv carbs the engine pulls more fuel because of added vacuum. Maybe try going leaner on the needle, down a pilot and keep your main the same..correct me if I am wrong guys, I am not positive.

down a pilot as in from a 45 to a 42 or 40? i'll try that becuase i've only changed out my main. thanks
 

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interesting, used to see the same thing on 660 raptors, running poorly, guys adjusting the jetting.... then finding the intake valves where tight............ frustrating.......

I'd look at dropping the needle back to the recommended JD setting, fifth clip is adding fuel on the low end, yu could just be to rich

Have you done anything to check / adjust the accelerator pump settings ??
 

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Discussion Starter · #7 ·
interesting, used to see the same thing on 660 raptors, running poorly, guys adjusting the jetting.... then finding the intake valves where tight............ frustrating.......

I'd look at dropping the needle back to the recommended JD setting, fifth clip is adding fuel on the low end, yu could just be to rich

Have you done anything to check / adjust the accelerator pump settings ??
ok, i can go back up a notch to see if it cleans it up a bit more...just thought the bogging indicates fuel starvation, but i'm definately still learning...thanks for the advice
 

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Hey guys I have a 525 with open air box and modded stock exhaust. I had the carb bored to 42mm running a 45 pilot, 185 main, and red JD needle at the recommended setting at 4500ft elevation. After I had the carb bored I experience a slight bog if I am crusing at 1/4 throttle and then go wide open. It is fine if I go from idle to WOT. Am I just going to have to play with the needle clip position or does something have to be done with the AP. I haven't messed with it a lot yet and was looking for preliminary guidelines.

Thanks
 

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Discussion Starter · #9 ·
I'm freakin stumped! went to the dyno last night and basically i was off the charts lean. what's worse is they couldn't dial it in or even figure out what was causing it. they went up as high as a 210 main, 7th clip on the needle and STILL LEAN!!! WTF! they even did a run with no main at all...yup, still lean. so obviously i have a bigger issue, i'm thinking, than just jetting. i don't know where to even start now, but the only thing i have done is swapped back to my stock needle, threw a 185 back in, 45 pilot, f/s 2 turns. actually seems to be running ok, but need to get back on the dyno ASAP to see if it really helped. promising though because it never ran good with a 185 and the JD needle....so hopefully it was the needle, it's getting rediculous now. anyone have any experiences or issues like this?
 

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when you stab the throttle it is lean and stays lean even after a few seconds? if so
I'd say one of two things, who bored your carb? remove the carb and open the throttle wide open, look inside the carb you should see a small 1/2 circle piece at the bottom of the throat where the needle would norm. be if that was removed when the carb was bored, there's your problem, if it is still there, try the HRC needle, we have found some bikes need the HRC needle, others get by without it, the HRC needle is smaller from about 75% to 100% throttle, which acts just like a bigger main jet.
 

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Itll be hard to get the lean issue to go away completely on the dyno. But with the carb mods we did to mine it completely elimated the issue when out riding it. I also think doing the hrc needle will help. The jd needles just didnt work for me either. I think they are geared more towards STOCK machines. The hrc needle helped my machine tremendously after I bored the carb. I also drilled and tapped for a leak jet and modded the acc pump squirter. All things Ranchero can do for you if you send him your carb. Good luck
 

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I had cut7 from over on KTM talk do the carb boring. I think the piece you are talking about is still there, but I cannot be positive. I just had the carb off last night rejetting it for 2200ft and 40 degree weather. I still have the tank off right now so maybe I'll go look. The HRC needle is from Honda, correct? If I walk into a dealership will they know what I am talking about or do I need to get one for a specific machine?
 

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I had cut7 from over on KTM talk do the carb boring. I think the piece you are talking about is still there, but I cannot be positive. I just had the carb off last night rejetting it for 2200ft and 40 degree weather. I still have the tank off right now so maybe I'll go look. The HRC needle is from Honda, correct? If I walk into a dealership will they know what I am talking about or do I need to get one for a specific machine?
Cut7 has a good rep. so the carb is most likely done correct, I bet the needle will fix your problem.
When at the Honda dealer, ask for 06 450R HRC carb kit, should be around $28 and come with a needle, main jet, leak jet and I think a pilot jet...
If this fixs your problem let us all know
 

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Discussion Starter · #14 ·
hey guys, thanks for the replies and suggestions. It absolultely WAS the JD needle. nothing against those guys but that needle just didn't work for my carb. i just never thought to try my stock needle while i was going through the processes of elimination. i put the stock one back in and took it to little sahara this weekend and dyno'd it there as well....problem solved!! one main jet change to a 192 and i put down just under 54 power with just under 38 torque. she's runnin great now. Thanks again everyone.
 

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hey guys, thanks for the replies and suggestions. It absolultely WAS the JD needle. nothing against those guys but that needle just didn't work for my carb. i just never thought to try my stock needle while i was going through the processes of elimination. i put the stock one back in and took it to little sahara this weekend and dyno'd it there as well....problem solved!! one main jet change to a 192 and i put down just under 54 power with just under 38 torque. she's runnin great now. Thanks again everyone.
If you try the HRC needle you'll drop the main jet even more, the JD kit works great for stock bikes, as soon as you start modding the thing starts bogging and needs a hugh main jet.

Glad you got it running good!!!
 

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Discussion Starter · #16 ·
If you try the HRC needle you'll drop the main jet even more, the JD kit works great for stock bikes, as soon as you start modding the thing starts bogging and needs a hugh main jet.

Glad you got it running good!!!

thanks ranchero, gonna try that HRC needle for sure.
 
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