1995 DS80 bogging need help

[TheGambit220]

My son was given a 1995 DS 80 that sat for a while. I did the normal tune up things and got it running. It will run perfect at idle, can crack open the throttle no issues. Get on it and put it under load and the bike will bog bad. It varies on how bad it is, sometimes it will bog and clear up, sometimes it will shut off. Starts right back up. For sure once it warms up its at its worst. I have been working it for a while and have changed the carburetor, spark plug several times, air filter, base gasket, head gasket, reed valve and gasket. It runs way better than when this all first started, but the bog will not go away. I was thinking coil, but I thought for sure it was the carb and that didn't fix it. With the new carb I have the needle on the top clip seems to run best here, and now the air screw is almost all the way in. It was 2 full turns out with the original carb.  I do not think this is my issue as the bog was  exactly the same with both carbs. So before I come out of pocket again Im trying to get some thoughts. Again I now am thinking coil. Please let me know what you think.

 

Thank you

[TheGambit220]

also if I throttle it or clutch it and get past the bog it runs perfect. It is for sure the hotter it gets the worse it gets. I just tried adjusting the carb again it is 1 full turn out so the air adjustment is good. It will idle good, but as soon as you try to take off that is when it bogs, or if you slow down to idle and try to take off. You can throttle it get past it and she is off and running. 

[78SuzyQ]

is the carb balanced ? if the carb isn't balanced (as in completely centered with the intake port) it will never run right, some bikes intake boots have a little slot on the top to level and balance the carb when you push it in, some bikes don't.. 

 

 

First make sure your air filter is not clogged or dirty, Then turn the air screw all the way in, then turn the air screw 1 and 1/2 turns out counter clockwise then rev the motor up high rpm and adjust the airscrew until the rpm is at it's highest from what you can hear. 

 

Then jump on the bike and ride it and tinker with the air screw until you have the best throttle response if no throttle response or changes occur, look up at the left picture of the mikuni tuner there you will see what the jet/needle/main/pilot does in relation to the rpm range.  From 0 to 1/4 throttle it's the Pilot system, throttle valve and Needle Jet. From 1/4 throttle to 3/4th throttle it's the jet needle. From 3/4th to Full Throttle it's the main jet .. you get the picture. Now it's your job to find out what range the bog is at ... and that's going to be the clue as to what you need to look at in the carb system. Go ahead and also take off your spark plug and look at the bottom of it to see if you're running rich or running lean. From what I hear you're running lean (hot) more air less fuel, Top needle clip position = leanest  Lowest needle clip position = richest you've got your air screw all the way in substituting the lean position it by richening the air screw. So keep that in mind.

Edited January 18, 2016 by 78SuzyQ

[TheGambit220]

I have tried everything with the carb except jets, but this is a brand new carb and it runs exactly the same as it did with the original. The problem is when the bike is hot, from either a full stop or just idling slow in a turn, you roll the throttle to go and bogs out. If I throttle it I can get past the bog than it runs like it should. Slow down roll the throttle and bog. Other than the carb what could it be? I ran it with no air box, no change. I ran it with exhaust off, no change. At idle you can rev it all you want, no issue, but as soon as its under load it bogs out. 

[78SuzyQ]

I have tried everything with the carb except jets, but this is a brand new carb and it runs exactly the same as it did with the original. The problem is when the bike is hot, from either a full stop or just idling slow in a turn, you roll the throttle to go and bogs out. If I throttle it I can get past the bog than it runs like it should. Slow down roll the throttle and bog. Other than the carb what could it be? I ran it with no air box, no change. I ran it with exhaust off, no change. At idle you can rev it all you want, no issue, but as soon as its under load it bogs out. 

 

tip the bike to the left then rev up the motor on idle then tip the bike to the right during idle and rev up the motor look for throttle rpm changes when you tip the bike to one side or the other 

 

other than compression and carb issues i can't think of anything 

 

there are a lot of different things that could go wrong with fuel/air delivery 

 

but like I said check your Spark plug 

[deer4011]

Sounds like the compression.  My js550 jetski would do the same thing.

[TheGambit220]

checked the compression, all good there. I saw another tread, im pretty sure its the ignition coil breaking down. I will get a new 1 soon, if it fixes it I will post up. 

[Rideon'03UC]

As far as the suzuki ds80 problem: no bottom end power ; poor idle; occasionally revving out of control from a standing idle.  ( the engine will produce loads of power through the power band though when you get it moving)...... I just tore down my son's ds80 with these very symptoms. I had tried the head,cylinder gasket replacement along with a new reed and also mag side crank seal and still it ran like s*^t. It wasn'the until I split the engine and pulled the crank out ( that's what you have you to do to get at the right side seal) . The right side crank seal was destroyed . A lot of work just to change the seal, but the bike runs perfect now. It was just a bad air leak causing the problem.  Hope this helps

Edited May 29, 2017 by Rideon'03UC

[James Wallbank]

On 5/28/2017 at 5:27 PM, Rideon'03UC said:

As far as the suzuki ds80 problem: no bottom end power ; poor idle; occasionally revving out of control from a standing idle.  ( the engine will produce loads of power through the power band though when you get it moving)...... I just tore down my son's ds80 with these very symptoms. I had tried the head,cylinder gasket replacement along with a new reed and also mag side crank seal and still it ran like s*^t. It wasn'the until I split the engine and pulled the crank out ( that's what you have you to do to get at the right side seal) . The right side crank seal was destroyed . A lot of work just to change the seal, but the bike runs perfect now. It was just a bad air leak causing the problem.  Hope this helps

I have a 96 that is having this same issue but I’m finding it’s not the ignition. Just rebuilt the top end put two carb kits in it. Got it to idle on the weekend ran great for an hr then had the same issues as original poster

[Zax]

Does anybody know How many turns out the fuel screw is supposed to be turned out on a 1995 ds80 carburetor? 

Edited May 4, 2020 by Zachary Surunis

[Blastedapple]

I believe it is 1.5 turns