1984 Suzuki DT 40 Throttle Problems

[wafshgod]

I have a '84 DT 40. I recently bought the boat and motor so i don't know alot of history. The motor seems to run fine at lower speeds 1/2 throttle or less. When i give it full throttle it bogs downs and dies after about 30 seconds. At first i thought it was a fuel problem. I have a new filter, replaced the diaphram kit in the fuel pump, checked to make sure the air vent is clear, pretty much everything but mess with the carb. Today i had it running at full throttle(for a short time) and pumped the fuel bulb from the tank thinking it may be starving for fuel, it was tight. Instead i think it is not burning the fuel at the higher end quick enough.

Both plugs appear to be working, i thought to replace them first. I do not know how to test for enough spark.

Any Thoughts?
Thanks for reading

 

[deejaycee_2000]

Re: 1984 Suzuki DT 40 Throttle Problems

time for a carb rebuild .....

 

[bgbass.1]

Re: 1984 Suzuki DT 40 Throttle Problems

I agree carb. rebuild

 

[wafshgod]

Re: 1984 Suzuki DT 40 Throttle Problems

Thanks for the input. This is the last thing in the fuel system.
Is this a fairly simple process or should i take it to the local shop. I have the service manual and the rebuild kits are cheap at Brownspoint.com.
It doesn't look to difficult.
Any input?

 

[deejaycee_2000]

Re: 1984 Suzuki DT 40 Throttle Problems

it is simple, just concentrate when taking apart not to leave any thing out when putting back together, all you need is some carb cleaner .... take the carbs apart and soak all in carb cleaner for a couple of hours, then blow out with compressed air and get in all the little places so all is 100% clean, then put back together ..... then you can adjust the air/fuel mixture screws a bit ..... turn inwards to soft stop then from there turn outwards 1 and a half full turns and then run the motor nice and hot and then adjust the screws slightly till you get the perfect idle .......

 

[hopalong]

Re: 1984 Suzuki DT 40 Throttle Problems

Thanks for the input. This is the last thing in the fuel system.
Is this a fairly simple process or should i take it to the local shop. I have the service manual and the rebuild kits are cheap at Brownspoint.com.
It doesn't look to difficult.
Any input?

I would suggest to take some pics before, during, and when assembling the carbs. Pics are worth a K words. Doing one carb at a time gives you a reference for when you do the other. The rebuild should be easy.

As a note, when you remove the bowl with the float/needle and seat still intact, and before you remove the needle and float, invert the bowl and see if the needle sticks when the float drops. If it does then it was most likely the problem or part of the problem. It would be good to know if the needle was sticking. But be sure to go ahead and clean/replace the needle/seat and other parts not just the needle/seat.

 

[wafshgod]

Re: 1984 Suzuki DT 40 Throttle Problems

Thanks for the input i ordered a kit last night so i will try it when it comes. I am fairly new to this site but have found it to be very helpful on a few occassions.
Thanks Again