My bike bogs down when I rev it!

[Increda Boy]

I have a blaster with new pipes, reeds, air filter, carb kit, and a 300 main jet. My bike will idle slowly but it works. Whenever i rev the throttle the engine will bog down unless i feather it. In other words, i have to rev it rapidly to get the rpms up. If i just go straight foward and gas it the engine will die. What could the problem be??? There are no air leaks and it has a brand new spark in it. Im mixing a 32:1 ratio. I cleaned out the carb, may have to clean it again. I forgot to mention that the bike has no power in first gear when i gas it all the way. I used to be able to pop wheelies in first gear no problem. thanks in advance!

 

[Increda Boy]

oh yeah, the piston pressure is at 130

 

[DLK666]

Ive got a similar problem, my first gear power is dodgy, also when i first start the bike(cold start) it bogs and sounds very rich, but once ive ridden it for about two or 3 mins(at full throttle while it is boggy and not revving up) it comes right and revs properly......anyone know how to fix this?

To answer your question Increda Boy, are you sure youre not running a bit on the rich side, maybe try a smaller jet? (for the record, if i ever think im running lean i cover the holes drilled in the airbox one at a time and see if it improves or gets worse, you could try that aswel to see if your maybe running lean?). Also is your TORS disabled?

 

[DLK666]

Im no expert but those are just some things id check if i had the same problems as you are having...

 

[gb blaster]

Ive got a similar problem, my first gear power is dodgy, also when i first start the bike(cold start) it bogs and sounds very rich, but once ive ridden it for about two or 3 mins(at full throttle while it is boggy and not revving up) it comes right and revs properly......anyone know how to fix this?

To answer your question Increda Boy, are you sure youre not running a bit on the rich side, maybe try a smaller jet? (for the record, if i ever think im running lean i cover the holes drilled in the airbox one at a time and see if it improves or gets worse, you could try that aswel to see if your maybe running lean?). Also is your TORS disabled?

Plug chops the only way to check your jettings

What's ur mods? What kind of pipe, airbox lid on off, filter, carb?

What's ur pilot jet at? And is it clean. You pilot is responsible for low end throttle.

Main jet circuit is responsible for ur top end pull.

But is the air filter clean, also have u deleted the tors, and parking brake?

 

[JBRoc01blaster]

At first glance the symptoms tell me you could be running rich, your float height could be off, or bad reed petals. I know this might sound stupid but is your choke pushed in all the way ? If you had your choke pulled out it would cause the quad to run like crap after warm up, especially when given gas. Sometimes its the small things that get over looked !

 

[DLK666]

Plug chops the only way to check your jettings

What's ur mods? What kind of pipe, airbox lid on off, filter, carb?

What's ur pilot jet at? And is it clean. You pilot is responsible for low end throttle.

Main jet circuit is responsible for ur top end pull.

But is the air filter clean, also have u deleted the tors, and parking brake?

Ill look at the filter thanks. Dmc pipe, 300 jet, uni filter, drilled airbox, no snorkel. The problem im having when cold is at wot so I doubt itd be a pilot jet problem, and my carb etc should be very clean still.

 

[JBRoc01blaster]

I have a similiar set up as you, only difference is I have the FMF ... I run a 280 main and that's on the rich side ! Plug chop to confirm but regardless of what's causing your problem I would say your most likely running rich with that 300 . And if the problem is at wot as you stated that would definitely point to your main jet.

 

[Blaaster]

Ill look at the filter thanks. Dmc pipe, 300 jet, uni filter, drilled airbox, no snorkel. The problem im having when cold is at wot so I doubt itd be a pilot jet problem, and my carb etc should be very clean still.

When cold you should be nowhere near WOT, it is very important to warm up the motor before fanging it.

I run a DMC and it prefers a stock needle with the clip on the lowest setting in winter, and up one clip in summer.

 

[DLK666]

When cold you should be nowhere near WOT, it is very important to warm up the motor before fanging it.

I run a DMC and it prefers a stock needle with the clip on the lowest setting in winter, and up one clip in summer.

Doesnt matter how long I warm it up for, when I first hit wot its all boggy, then after a min or two at wot its fine. When you say the lowest setting do you mean the richest setting?

 

[Blaaster]

Doesnt matter how long I warm it up for, when I first hit wot its all boggy, then after a min or two at wot its fine. When you say the lowest setting do you mean the richest setting?

Yup DMC absolutely loves a rich setting on the needle, read through the installation instructions and they recommend the needle to be at its richest setting.

 

[JBRoc01blaster]

I'm glad blaaster is helping you in this thread, he has experience with that pipe ... Follow his suggestions and your motor should be running nicely in no time !

 

[DLK666]

I'm glad blaaster is helping you in this thread, he has experience with that pipe ... Follow his suggestions and your motor should be running nicely in no time !

Ofcourse, his, and all of your guys help is much appriciated

 

[Blaaster]

When boggy is mentioned I think lean, where the motor falls flat and seems to die.

When the motor sounds like a 4 stroke and sounds like it is babbling and trying to get through a choked situation, then I think rich.

The choke (fuel enrichment) can help in the diagnosis.

If you put the choke on a little and it runs better then it is too lean.

If it runs worse and babbles more, then the jetting is too rich.

One must plug chop to confirm any change in either main jet or needle settings.

 

[DLK666]

Thanks for the help guys. Blaaster, what mods do you run and with what jets? Just want to compare to check if im at the right place with my mods? More or less what altitude are you at? And do you change your main jet between winter and summer?

 

[Blaaster]

Thanks for the help guys. Blaaster, what mods do you run and with what jets? Just want to compare to check if im at the right place with my mods? More or less what altitude are you at? And do you change your main jet between winter and summer?

My mods are very mild.

DMC Alien pipe.
Re chambered head, torodial.
Reed spacer block, (which needs no jetting adjustments).
Polished exhaust port, cleaned up inlets, but no port timing changes.
Dual stage reeds.
Foam air filter directly on the carby throat.
Pre mix of 25:1 bean oil.

I am at sea level and use a 26mm stock carb with a #32.5 pilot jet.

The winter jetting is at #310 - #320 depending on temperature, with the needle at its richest setting.

Summer jetting #300 - #310 again dependant on temps, needle up one clip.

I too am one of the few, maybe the only one who adjust the oil/fuel ratio to fine tune the jetting.

I usually run one jet size richer than the norm, with very little loss of power, I love the peace of mind that it gives me.

Ihave never fouled a plug due to my greater oil concentration or richer jetting.

 

[DLK666]

My mods are very mild.

DMC Alien pipe.
Re chambered head, torodial.
Reed spacer block, (which needs no jetting adjustments).
Polished exhaust port, cleaned up inlets, but no port timing changes.
Dual stage reeds.
Foam air filter directly on the carby throat.
Pre mix of 25:1 bean oil.

I am at sea level and use a 26mm stock carb with a #32.5 pilot jet.

The winter jetting is at #310 - #320 depending on temperature, with the needle at its richest setting.

Summer jetting #300 - #310 again dependant on temps, needle up one clip.

I too am one of the few, maybe the only one who adjust the oil/fuel ratio to fine tune the jetting.

I usually run one jet size richer than the norm, with very little loss of power, I love the peace of mind that it gives me.

Ihave never fouled a plug due to my greater oil concentration or richer jetting.

Thanks for the help....judging by the facts uve given im probly a tad rich cz im using a 300jet with dmc pipe, drilled airbox nd uni filter, considering im at 1500m altitude....

 

[Blaaster]

In summer and at 1,500m you could try the needle in the middle clip.

Whatever you do plug chop your adjustments.

 

[DLK666]

In summer and at 1,500m you could try the needle in the middle clip.

Whatever you do plug chop your adjustments.

I believe its in the middle position at the moment, but yeah, its winter here now so ill play around with the needle a bit