Bike bogging at certain rmp in each gear.
07-03-2016, 06:29 PM
#1
Night Rider
Squid
Thread Starter
Join Date: Mar 2014
Location: Idaho
Posts: 74
Bike bogging at certain rmp in each gear.
Just running this by everyone before i tear apart my carbs to clean them and switch main jets out.
My hawk runs normally up to a certain rpm in each gear 1st 8000 2nd 7000 3 6500 4th 6000 and so on. after that it boggs down like if the engine is getting flooded with little blips of power after that rpm but it will not go more then 300 rpm above that.
Does this sound like a overly rich main jet to you guys or are there other problems you guys can think of?
I did do an engine swap and i had a friend try and work on the carbs with the old engine. I'm thinking that since the old engine wasn't running properly I may need to go back to the old jets and do some other adjustments.
My hawk runs normally up to a certain rpm in each gear 1st 8000 2nd 7000 3 6500 4th 6000 and so on. after that it boggs down like if the engine is getting flooded with little blips of power after that rpm but it will not go more then 300 rpm above that.
Does this sound like a overly rich main jet to you guys or are there other problems you guys can think of?
I did do an engine swap and i had a friend try and work on the carbs with the old engine. I'm thinking that since the old engine wasn't running properly I may need to go back to the old jets and do some other adjustments.
07-03-2016, 07:22 PM
#2
VTR virgin
Superstock
Join Date: Mar 2015
Location: Auckland, New Zealand
Posts: 446
You might be getting some fuel starvation caused by the vacuum petcock. Before launching into the carbs it would be worthwhile inspecting this component to see if it is doing the right thing. If you didn't know, the vacuum petcock shuts off the fuel when the engine is not running. It uses a vacuum signal from the rear inlet port to move a diaprgam which opens a valve and allows fuel to flow to the carbs. If the diaphragm gets damaged due to age it may not be opening fully and limiting fuel flow when there is high demand.
07-04-2016, 09:06 PM
#5
Who are you?
SuperSport
Join Date: Aug 2009
Location: Las Vegas, NV
Posts: 731
I would order a new one, regardless. It's a delicate rubber piece that will eventually fail, and it can cause you issues when it does. Furthermore, there may be a pinhole in it that you cannot see, and it's fairly inexpensive. Did you also make sure that the vacuum hose was attached to the correct place on the petcock?
You would need an absurdly massive main jet for it to get so flooded that the RPM won't increase, so I wouldn't rely on that being it, but I would make sure that your settings are correct. I would also make sure that you properly seated the carbs, as they can be a tad tricky and the front or rear may sometimes not fully seat. This will wreak havoc with how the bike runs. Make sure to clean everything out in the carbs, and make sure that you have smooth operation of the float needles and that they aren't binding/getting stuck. That can also cause issues.
You can also check your spark plugs, making sure they're fresh and fully seated. Same for the coils, ensure that they are properly seated and that they're tight at their mounting points with no corrosion.
You would need an absurdly massive main jet for it to get so flooded that the RPM won't increase, so I wouldn't rely on that being it, but I would make sure that your settings are correct. I would also make sure that you properly seated the carbs, as they can be a tad tricky and the front or rear may sometimes not fully seat. This will wreak havoc with how the bike runs. Make sure to clean everything out in the carbs, and make sure that you have smooth operation of the float needles and that they aren't binding/getting stuck. That can also cause issues.
You can also check your spark plugs, making sure they're fresh and fully seated. Same for the coils, ensure that they are properly seated and that they're tight at their mounting points with no corrosion.
07-05-2016, 06:58 PM
#6
Night Rider
Squid
Thread Starter
Join Date: Mar 2014
Location: Idaho
Posts: 74
I did put it on the right way. but i tore into the front carb today and the needle was actually bent and it looks like the pilot jet was pretty dirty as well i can just barely see a pinhole of light through it so i ordered a dynojet kit today and ill be breaking into the other carb later today to see if there is anything else i need to buy and replace.
i also already ordered new plugs they should get here tomorrow so that will help a bit i hope. If im lucky i wont need to replace anything else. ill also take a look at the coils to see if they need any cleaning up.
thanks for the help and ideas.
i also already ordered new plugs they should get here tomorrow so that will help a bit i hope. If im lucky i wont need to replace anything else. ill also take a look at the coils to see if they need any cleaning up.
thanks for the help and ideas.
07-06-2016, 07:56 AM
#7
Senior Member
SuperBike
Join Date: Sep 2010
Location: Bisbee, AZ
Posts: 1,871
I did put it on the right way. but i tore into the front carb today and the needle was actually bent and it looks like the pilot jet was pretty dirty as well i can just barely see a pinhole of light through it so i ordered a dynojet kit today and ill be breaking into the other carb later today to see if there is anything else i need to buy and replace.
i also already ordered new plugs they should get here tomorrow so that will help a bit i hope. If im lucky i wont need to replace anything else. ill also take a look at the coils to see if they need any cleaning up.
thanks for the help and ideas.
i also already ordered new plugs they should get here tomorrow so that will help a bit i hope. If im lucky i wont need to replace anything else. ill also take a look at the coils to see if they need any cleaning up.
thanks for the help and ideas.
07-07-2016, 02:52 PM
#8
Night Rider
Squid
Thread Starter
Join Date: Mar 2014
Location: Idaho
Posts: 74
I have and i looked a a lot of the other threads as well and the dynojets are the closest to the stock needles in shape profile and they are adjustable without shimming the needles with washers and im mostly just planning to use the needles and maybe use the jets since they do taper to help atomize the gas and help burn a bit cleaner. but we will see i dont plan on useing the springs or drilling the extra holes on the slides and i will do some testing and tuning based off his suggesting based off what it does from there.
07-09-2016, 08:11 AM
#9
Night Rider
Squid
Thread Starter
Join Date: Mar 2014
Location: Idaho
Posts: 74
put in the needles and jets from the dynojet and its running a lot better now i just need to do a little tuning on the mixture screw and i need to clean and re-oil my filter to let a little more are through as its running a little lean without the filter and a little rich with it.
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