1997 dt 65 will not rev in gear above 2,500 buzzer sounding

[bodybag]

hi,

I need your help! just got a 1997 dt 65 2 stroke but having major problems with her. She starts fine, revs to 5000 rpn + on thottle start lever and on muffs in gear, however when in the water in gear it runs fine untill it reaches 2,500 rpm then it will not rev higher becomes lumpy but runs fine if you run below 2500 rpm. a buzzer is sounding every 10 seconds.

Compression test is fine, new plugs, new water sensor, new oil sensor/filter, the oil has been filtered/replaced. all electrical conections earths ect under the hood have been checked and replaced as needed. tried the reset button by the trim and tilt and no change.

top cylider plug a little black compared with others if kept above 2500rpm, below it is normal colour.

my questions are:

does this engine have an limp mode or limitor?
if so how do you reset it?
how does the limp mode work does it limit the top cylinder.
any idea what is stopping this engine going above 2,500 when in the water and in gear?

any advice or help would be great guy's

thanks tony, devon UK

[mphelle8vld]

Is your monitor gauge hooked up? It should tell you whats setting the alarm.

You should run premix until you are sure all the air is out of the oil lines. In your case, either the oil is not flowing or the water pump impeller is not delivering enough water, both will sound an alarm and put it in limp mode.

After you solve the alarm issue, I would thoroughly clean the carbs.

[bodybag]

thanks

there is not a monitor fitted, sounds like it could be worth fitting one!,

can you advise when the buzzer will sound the engine has:
temp sender
water flow sensor
oil level sender this has two floats on.

I will pre mix until it is sorted,

thanks for the advice.

[mphelle8vld]

Overheat, low oil, low oil flow, and over-rev.

I would try to find one of these:
http://www.ebay.com/itm/TRACKER-3470...ht_3951wt_1081

[bodybag]

thanks

just ordered one of ebay in the uk £30 pounds s/h. that should help identify the problem.

thanks for you help. tony

[mphelle8vld]

Good price, let us know which indicator light gets a workout.

[bodybag]

d day!

connecting gauge up today, fingers crossed, it points me in the right direction!

[bodybag]

well gauge is on! have 3 green lights, from the three at the top, but the red "rev limit" is lit up also the "oil" is lit up both at the bottom of gauge. Have replaced the oil flow sensor no change! one thing I did notice was that when i was bleeding the oil pump very little oil came out, When i have bled two stroke bike oil pumps in the past there is an pressured fast flow this was not the case with the DT?

Oil pump failed? what do you think guys?

[mphelle8vld]

Bleeding the pump is done with the motor off, it's gravity fed so oil leaks slowly out of the bleed screw. The sensor/filter should be "pre-filled" before re-inserting to keep as much air out of the lines as possible before bleeding. Make sure to run a tank of pre-mix and mark the tank to verify that oil is being drawn through the system.

I'm sure your pump is fine, that sensor will only sense a restriction in the filter or supply line. Make sure there is no debris clogging the supply line nipple at the bottom of the oil tank.

Run pre-mix until this is sorted!

[bodybag]

Cheers will do, I'm going to check all of the pipe work and filter leading to the pump again, checked the oil pump and like you said no problems found.

Is it possible to isolate the oil sensor and run on premix? bypassing the rev limiter?

Thanks for your help and advice it been very helpful.

[mphelle8vld]

While running pre-mix, you can disconnect the wires from the sensor, the CDI will think that oil flow is fine and should turn off the alarm.

[bodybag]

at wits end now, still no good, same problem, has had all wiring checked, new oil,water flow sensors, new CDI unit, all pipes, oil tank, oil pump, non return valve cleaned and checked. reset switch shows low volts 1.4 and when you push it to reset that drops to .20.

the gauge has 3 green lights lit, "limit" and oil are red and lit. the buzzer is still sounding,

Help! i have had to walk away from it today or get self referred for anger management! don't know what else to do. any advice?

[mphelle8vld]

Disconnect the large connector at the CDI that has the following wires:
brown/white stripe
brown/white stripe
blue/white stripe
pink/blue stripe
blue

Run it again, let me know what you find.

[bodybag]

will do thanks,

[bodybag]

Ok, disconnected the wiring block, gauge still showing the same, 3 green, red limit and oil lit. however the buzzer is not sounding at all.

what do you think??

thanks tony