Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Bolens Lawn Tractor "SURGES" when mowing


charon187's Avatar
Member

Join Date: Feb 2009
Posts: 11

04-06-09, 06:50 PM   #1  
Bolens Lawn Tractor "SURGES" when mowing

First of all a very big THANK YOU to the guys who helped me with my flywheel problem a while ago Airman was one of the many great guys on this forum who really helped me . (turns out the lead to the anti afterfire solenoid shorts somewhere,and after disconnecting it it runs forever)

so anyway it ran great for a few weeks and i really put it thru its paces and abused it by tackling greasewood. anyway now its has spawned a new problem of surging on light weeds when mowing. were talking about weeds that are less than 6 in tall and mowing in first gear with the deck halfway down.

i think that maybe the belts are loose? maybe i destroyed the belts when mowing the greasewood? (i know its not meant to do that )
im trying to figure out if its just a belt adjustment or i should replace the belts all together.

when it starts to surge i disengage the mower deck and depress the clutch/brake untill the surge is over then slowly lower the mower deck back to midway then continue for a bit untill i have to repeat the process.

in regards does anyone have a easy explination on belt adjustment? the MTD website leaves me slightly confused on how to best accomplish this.

Many thanks in advance!!
cheers!Beer 4U2

 
Sponsored Links
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

04-06-09, 08:43 PM   #2  
Describe "surge" better. Is the mower lurching forwards, or the engine revving up and down, or the blades spinning fast and slow? Generally surging describes an engine revving up and down. If this is the case, the carburetor needs cleaning or the engine is otherwise starving for fuel.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
charon187's Avatar
Member

Join Date: Feb 2009
Posts: 11

04-07-09, 01:03 PM   #3  
surging as in engine reving up and down.
the carb is spotless as i have rebuilt it many times figuring out the other problems i had with it.

the surging only occurs under load with the mower deck engaged.
to cease the surge i disengage the mower deck then after the engine returnes to normal i engage the mower deck again to the highest position. after a few seconds i lower the deck to the mid position. it seems that the mower isnt fully engaged until lowered to the mid position. the sound of the blades becomes much louder and faster at the mid position as opposed to the highest position, which is why im thinking belt adjustment.

this occurs on flat ground or slopes when a certain amount of load is applied to the blades (density of cutting being done)

if it is still a fuel problem in your opinon where would i look next as the carb is perfectly spotless even the tiny passages are clear. their is only one adjustment screw that has a built in stopper to keep it from turning more than 1/4 lean or rich.

maybe im overlooking something?
thanks cheese! your one of the guys who helped me before and i appreciate it greatly!!!
Cheers!

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

04-08-09, 12:01 AM   #4  
Yep, still a fuel problem. You probably have some crud still in a passageway... probably not enough to block the passage, but enough to restrict it some. The belt adjustment may also need attention, but that's not the cause of the engine surge. If you didn't take the air fuel adjustment screw out, you need to to clean it and the passages related to it. Pull the limiter cap off and remove the screw. You need to spray carb cleaner through every passage, run a torch tip cleaner from a welder supply company through every jet, and blow compressed air ~120 psi through all passages to verify that the carb is clean.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
charon187's Avatar
Member

Join Date: Feb 2009
Posts: 11

04-08-09, 10:47 AM   #5  
only thing i have not done is remove the limiter cap how do i get that off with out breaking it ? or do i just break it?

thanks cheese!
Cheers!

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

04-08-09, 08:21 PM   #6  
You can generally grasp it and pull it off with pliers. You may have to pry a little with a screwdriver to help it off. Also, did you remove the welch plug and clean the passages behind it?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
Search this Thread