Problem with Suzuki DT150 1989

[Americanec]

Update,
we found how to set the screws and we will do it .says 1 and 0,5 turn back .
I ordered water pump kit replacement and we do it.
at the same time we will check (open)the lower unit .

[Solarman]

I do hope you removed those needle valve seats in each float bowl, it is common for trash (identify any trash, or particles found in carbs) to lodge on the back-side of that seat, reducing the flow of fuel going to float chamber.

That #3 air fuel mixture screw is not right. But when cleaning carbs make sure all of those fixed jets are removed when soaking. Every tiny hole in jets, and carbs are there for a reason, and must be cleaned (by soaking), then blown out clear, and dry. Do NOT reem out any holes, they will come clean in soaking, and air pressure.

Good luck, post back on what you do.

[Americanec]

Hello Solarman,we did everything that you told me and the engine runs better,start anytime.
I will upload 2 videos ,first when we change the rpm to 700 and the second to 1000 .

https://youtu.be/-PrivBH0OL8


https://youtu.be/DH5xDXEjx_U

i read the rpm must be like 700 but the engine work better on 1000.
No lights on .
do you think the engine runs good?

[Americanec]

Update:We went to the lake and everything was ok.The engine worked well,only 2 times died but start right away.we found the the rpm meter doesn’t work well,when is off stay on 500 rpm ....we will check it later.
Thank you for your help Solarman.I hope everything is ok from now,if not i will write you again.
have a wonderful day

[Solarman]

I'd say set idle at 800 rpms. The closer you are to the normal idle setting, the better it will be for shifting. Likewise, you should be running some fuel additive in every tank of fuel. Are you running oil and fuel mixture with the oil injection system in the videos?

Don't change anything else till you run

Post back on what I asked.

[Solarman]

Good to hear it is running. Post again if more problems?

[Americanec]

Hello Solarman,how are you ?
we decided to check the pressure on all cylinders and we found that one of them (Checked on cold crank) is low.
5 of them showed 91,92 but the first one showed 65.
How high should be the pressure on this DT150 -1989?
the engine run but not so steady ,equable.
one more thing:All the sparks plugs were wet!
this is video how the engine works:
https://youtu.be/YNKxI2X4nyI

Any help what could be the problem?
Thank you

[Solarman]

Well 65 psi is to low, if the others are at 91-92. If you do not have compression leaking around head gasket for that cylinder then you either have bad rings, damaged cylinder wall, or loose connecting rod. I would NOT run motor at all until you find out why that cylinder is that low.

Options:

Pull that cylinder's head to see what it looks like, or a small camera and light through plug hole. To visually inspect that cylinder.

Or, you could pull the carbs and intake for that cylinder, and see if the reeds are ok, then pull the reeds to view that cylinder from the back.

It is not easy from this side of computer to tell what is best direction to go. With one cylinder down that much (more than 10% from the others), it does not sound very good.

Good luck, post back on what you find out.

[Americanec]

Hello Solarman,we opened the head and saw that one of the cylinder has a scratches.The problem is how to remove the whole engine to take out the other part.Nobody here in Nevada want to fix it.Only if we remove it and bring it to them.Do you think we can do that?or if you know someone who can fix it?

[Solarman]

The problem is not going to be the scratches, but the crank and main bearings (rod and wrist pin bearings). You may as well scrap the motor out. It will be cheaper to invest in another motor, with good compression on all cylinders. Stop throwing money at this motor, that is why the shops won't rebuild it, they can't guarantee it to run without new parts (crank, rod and piston assy).

Good luck.

[Americanec]

I am selling the engine.Of you are interesting please write me.