Jump to content
Sign in to follow this  

Brand New Bike with Flat Spot

Recommended Posts

Hi Guys, I have just purchased a brand new 2006 CRF450x from the dealer and shipped to my home in Jamaica. Problem I am having is that when riding at idle speed (no throttle) then cranking the throttle there is a flat spot or a bog instantly that remains if you dont let up, will even stall!!

Does anyone know of a simple fix? I have read up on the AP mod, but not sure if that applies. I have ordered the JD jet kit but have not received as yet.

Share this post


Link to post
Share on other sites
Hi Guys, I have just purchased a brand new 2006 CRF450x from the dealer and shipped to my home in Jamaica. Problem I am having is that when riding at idle speed (no throttle) then cranking the throttle there is a flat spot or a bog instantly that remains if you dont let up, will even stall!!

Does anyone know of a simple fix? I have read up on the AP mod, but not sure if that applies. I have ordered the JD jet kit but have not received as yet.

Jetting will help with this.

Share this post


Link to post
Share on other sites

rejet, a friend of mine had a similar problem. the jd kit seemed to have remedied it

Share this post


Link to post
Share on other sites
Hi Guys, I have just purchased a brand new 2006 CRF450x from the dealer and shipped to my home in Jamaica. Problem I am having is that when riding at idle speed (no throttle) then cranking the throttle there is a flat spot or a bog instantly that remains if you dont let up, will even stall!!

Does anyone know of a simple fix? I have read up on the AP mod, but not sure if that applies. I have ordered the JD jet kit but have not received as yet.

These bikes are not made to be hammered off idle with no load... hence the "flat spot". JD jetting helps the condition you speak of, however so does the AP mod and/or a 'quick shot'.

Ultimately your speaking off the "off idle bog".

Ride the bike... put it in gear, and roll on the throttle. Tell me how many times you WHAP the throttle to wide open when your out riding... and how many times your bike "bogged". :applause:

Have fun... you'll love the bike.

Share this post


Link to post
Share on other sites

perform the ap mod install a #90 lek jet,while you are jetting it you wont believe the differance. in my opinion the quick shot does nothing just my .02 on the quick shot

Share this post


Link to post
Share on other sites

ok thanks, but im a full time university student with 2 jobs.... i dont exactly have time to read every page on this forum... Accelerator Pump mod... gottcha

Share this post


Link to post
Share on other sites
ok thanks, but im a full time university student with 2 jobs.... i dont exactly have time to read every page on this forum... Accelerator Pump mod... gottcha

Not everyone does.

But you have time to reply to everyone's posts. :applause:

... with that said, do a little homework if you will before posting advice or information on product. Use the search function, or simply learn by other's. I'm trying to help ya out a bit, not be a weenie.

...and 2 jobs?! Man... that sucks.

Share this post


Link to post
Share on other sites
These bikes are not made to be hammered off idle with no load... hence the "flat spot". JD jetting helps the condition you speak of, however so does the AP mod and/or a 'quick shot'.

Ultimately your speaking off the "off idle bog".

Ride the bike... put it in gear, and roll on the throttle. Tell me how many times you WHAP the throttle to wide open when your out riding... and how many times your bike "bogged". :applause:

Have fun... you'll love the bike.

Actually I whap the throttle quite often, doing wheelies, the condition is really bad, I can't believe a brand new bike could leave a showroom like that! It happens once throttle is applied quickly not neccesarily full throttle. I am going to try rejetting and just the AP oring mod and see what happens.

Thanks for all the help

Share this post


Link to post
Share on other sites
Hi Guys, I have just purchased a brand new 2006 CRF450x from the dealer and shipped to my home in Jamaica. Problem I am having is that when riding at idle speed (no throttle) then cranking the throttle there is a flat spot or a bog instantly that remains if you dont let up, will even stall!!

Actually I whap the throttle quite often, doing wheelies, the condition is really bad, I can't believe a brand new bike could leave a showroom like that! It happens once throttle is applied quickly not neccesarily full throttle. I am going to try rejetting and just the AP oring mod and see what happens.

Thanks for all the help

Hmmm.....

So you ride along at idle... and whap the throttle to do a wheelie?! :lol:

That little bit more of info changes the issue a little bit. But again, our bikes STOCK aren't made to be whapped like you explained initially. Hence the reason you got the reply you did.

For example, put the bike on it's stand... let it idle. WHAP the throttle and hold it. Does it bog, and die?! IF YES, then it's normal. Take it off the stand... go out and hit second gear (for example) and again... WHAP the throttle (clutch out)... you shouldn't have much bog at all. If you do, maybe the dealer didn't prep your bike correctly. And if that's the case, take it back or do it yourself following the directions in the stickies.

:applause:

Share this post


Link to post
Share on other sites

Your second (last - second gear) scenario hits the nail on the head, only problem is that I bought the bike in miami from the dealer and shipped to Jamaica, so no dealer to take it back to. which stickie do i look at??

Share this post


Link to post
Share on other sites
Your second (last - second gear) scenario hits the nail on the head, only problem is that I bought the bike in miami from the dealer and shipped to Jamaica, so no dealer to take it back to. which stickie do i look at??

The ones in regards to your problem(s)... "Jetting".

All of the stickies are at the top of the page (450X forum)

http://www.thumpertalk.com/forum/showthread.php?t=473491

Share this post


Link to post
Share on other sites

you want them both while your doing the jetting do the mod. why would you want to do someting halfway??

Share this post


Link to post
Share on other sites

The JD Jetting kit comes with the O rings to do the AP mod and instructions.

When your kit arrives, and you jet the bike properly, you'll be good to go.

Share this post


Link to post
Share on other sites

Ok JD Jet kit has not arrived as yet, but a friend had some jets, so i have done the pink wire mod, changed main to 165, changed pilot to 48, standard needle clip moved from 2 to 5 and cut open the airbox as per "the wrench".

Bike no longer has the bog or flat spot, and i hooked up an airflow meter just to check what the mixture was saying, unfortunately it wouldnt give me a reading at the rear of the muffler, would need to bore the header and mount.

Upon test riding, i did find that going up the rpm very very slowly in any given gear when about half way up, it would kinda pop or give a slight miss fire around 4-6,000 rpm. Does anyone know if this is a result of being too lean or what?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×