Why does Susuki DT65 die on full throttle

" I have a 1988 DT65 Susuki mo

" I have a 1988 DT65 Susuki motor. At half to full throttle motor stalls out. Gas pressure is at 2lbs when it dies. I have good spark on all three plugs with timing light when it stalls. My timing at idle is on the T. When I bring it off idle it is about 10 degrees. It stalls out at about 32 degrees on timing light. New plugs, old ones were black. Fuel pump looked fine when I took it apart. The vacuum diaphragm had a slight sag in it. I switched gas tanks and it made no difference. Gas lines are all good. Please send any suggestions ASAP! "

"Dave.... The Susuki engine is

"Dave.... The Susuki engine is obviously not my cup of tea so to speak, however from what you've listed above, especially the black s/plugs, I would suggest that you check the following.

The timer base may be sticking which would keep the timing at a retarded setting or...

If the engine has set for any length of time (a month or more), the carburetors may be fouled slightly, causing a restriction of the jets. Either of these conditions, or a combination of the two would cause the problem you describe.

Hopefully a Susuki tech will jump in here who is more knowledgeable on your engine than I, but I did want to list those two possibilities.

Joe "

" Dave:
I have the same engin

" Dave:
I have the same engine and the same problem. I've rebuilt the carbs and fuel pump, replaced the filters and fuel lines. It's getting worse. It will actually run well for a few seconds at full throttle, then bog down like it's fuel starved, but I think I've eliminated that possibility. Did you ever get any answers? "

" Miked & Daylight Dave

" Miked & Daylight Dave

I have a 1987 dt 65 that was giving me all the same troubles you are having. I cleaned carb's., put new fuel pump kit in, kitted 1 carb., spent around $250.00 tinkering. Today I decided to pull the carb's., intake, and reeds out to take a look at the inside and found that the middle main bearing is gone (all ball bearings missing and probably ground up) I guess it's time to overhaul. Found out that you must change crank and pistons as one assembly. (hopefully cylinder walls not to scared) "

"Hi Chaps,

I also have a dt

"Hi Chaps,

I also have a dt65 which was dying when you put the revs up. It turned out to be a faulty 'oil reset unit'. The electics on this model are pretty sofisticated, there are monitors on the oil level/oil flow rate/engine temperature which 'talk' to the cdi ignition unit. If any of these sensors detect what they think is a problem they reduce engine spark causing the syptoms you've all described above. To confirm this try pushing the 'oil level reset switch' which is a red button on the right hand side of the motor (you must do this with the engine running), you'll probably find that 'hey presto' the motors now runs fine!! You can now investigate which of your sensors is faulty or, in my case, it turned out to be the oil reset unit. Now all I need is to source a replacement -anyone got one? As an alternative to replacement you can simply press the reset switch each time you start the motor.
The motor has done thousands of hours and has been super reliable apart from this. If anyone has a spare oil reset unit or ignition cdi they can email me at [email protected]
Regards,
Clive"

" As a follow up to my previou

" As a follow up to my previous I thought you might like to know of a fix. I was correct in my diagnosis of a faulty 'oil reset unit'. To work round the problem I have disconnected the unit from the cdi unit. What this does is stops the faulty unit 'talking' to the cdi which in turn stops the cdi from reducing engine spark. The oil flow/water sensors still work and give audio warning if a problem does occur. This all means the engine runs fine but I should replace the oil reset unit if I can find/afford one. For anyone that wants to try this fix just disconnect the two wires that join the oru and cdi, from mememory they are light green with a thin black tracer and yellow with a thin blue tracer (I could be wrong on the colors but can confirm this if anyone want to email me)
regards,
Clive "