Suzuki DF70 no more than 3200 rpm.

[marautica]

hi.
I have a Suzuki DF70 only up to 3200rpm.
With suzuki diagnostic software does not detect any problem.
The pressure of gasoline is good, the injectors were repaired and spark are new.
By measuring the compression in the pistons, have the number 1 - 6 kgs \ in number 2 - 6kgs \ in number 3 -12 lbs and number 4 -12 kgs.
This difference between compression pistons could be the cause of the lack of rotation.
My question is where could be the problem? Valves in? ring set pirtons ?
Liked to hear opinions.
Greetings.

[18pontoon]

hi.
I have a Suzuki DF70 only up to 3200rpm.
With suzuki diagnostic software does not detect any problem.
The pressure of gasoline is good, the injectors were repaired and spark are new.
By measuring the compression in the pistons, have the number 1 - 6 kgs \ in number 2 - 6kgs \ in number 3 -12 lbs and number 4 -12 kgs.
This difference between compression pistons could be the cause of the lack of rotation.
My question is where could be the problem? Valves in? ring set pirtons ?
Liked to hear opinions.
Greetings.

How are you measuring compression? Those dont look like correct compression readings. Make sure you measure compression with throttle wide open. I'll assume your readings were all kg/cm^3. The spec for DF70 is 13-16 kg/cm^3 with max 2 kg/cm^3 difference between cylinders. 1 and 2 are way below spec and different from 3 and 4 which are slightly below spec.

Service Manual states reasons for low compression are as follows:
Excessively worn cylinder wall
Worn piston or piston rings
Stuck piston rings
Poor seating of valves
Ruptured or otherwise damaged cylinder head gasket

I would check the head gasket between 1 and 2 to start (use soapy water to see if its leaking while running, bubbles will form). If the gasket is blown there it could explain 1 and 2 being low and 3 and 4 slightly below spec. Worst case its any of the other issues.

[vtr1005]

HI

what is this engine use for?

Is this engine always running in heavy load condition ?

what is the total working hours?

my experience is valve had damaged, and need to rebuild the engine, because it ran with a heavy load condition and a long working hours.

mainly i will change all the crankshaft bearing, conrod bearing, piston ring, valve stem seal, valve, reface the valve seat,

[TOPalmer3rd]

Are you swinging to large a prop?????

[prattvan]

What did you find out ?

[catacom225]

Sounds a bit strange that 1-2 are half of what 3-4 are, Try putting a tea spoon of oil in 1-2 and re test with WOT

[noelm007]

Not if the head gasket is blown between those two cylinders....