Hot restart issues

[alexanderfoti]

Hi all

Bit of an odd issues with the diesel bike at the moment.

If I go for a ride, get the engine nice and hot, and stop off somwhere for 2-3 minutes, then try to restart the engine.

It cranks for longer, the misfires and with the throttle wide open, acts as if though its fuel starved.

If I hold the throttle open with it misfiring, it passes after 2-3 seconds.

I had to turn off the engine for 20 seconds today to shout at somebody at a set of traffic lights, and restarting then was more difficult, but same scenario.

Any thoughts?

[coachgeo]

Sucking air??? and when bike is off and hot....... aka it has not sat for long.... the air is in a most inconvenient place(s)? When cold.......... aka sat longer... they air has all moved to one pocket and gets pushed thru in one no start swoop, starts on the next kick (or spin of starter) and all is good till enough air has been sucked in while operating. By this time bike is at normal Hot temps.

[alexanderfoti]

I think you are right with the air possiblity.

I have had many issues with air in the system. Mainly becuase I have this transparent fuel pipe, and its crap, its gone all hard over time and if the piping is disturbed it lets air in the many joints it has.

I am sure running WVO as well pulls air in more, as the fuel is ticker. I will have a look at my hose clamps!

[Nanko]

Valve clearance?

[alexanderfoti]

Valve clearance?

Compression is still good when warm

[alexanderfoti]

Valve clearance?

Compression is still good when warm

although I will check it when my fuel tank is empty lol

[gilburton]

I think you are right with the air possiblity.

I have had many issues with air in the system. Mainly becuase I have this transparent fuel pipe, and its crap, its gone all hard over time and if the piping is disturbed it lets air in the many joints it has.

I am sure running WVO as well pulls air in more, as the fuel is ticker. I will have a look at my hose clamps!

Fit proper fuel pipe. It's not expensive(even from Halfords)

[alexanderfoti]

I have proper fuel pipe, I just need to find a time to do it when the fuel tank is empty Lots of annoying joints.

[gilburton]

Why do you have to wait till the tank is empty?? Do you not have a tap on the tank??
My own view is that either you have an air leak or your WVO is thickening up in the cold weather causing a restricted supply??
Best to start from basics and run a straight diesel supply direct via a clean filter to your pump. Use new hose and good clips.
Check that you are getting a good flow out of the tank as the tap filter may be blocked??
If that eliminates your problem then the answer lies in your other tubes/WVO??

[alexanderfoti]

I do have a tap but also have a fair bit if fuel in the pipes and I don't want to affect my mpg readings (sad I know).

I doubt it's the wvo thickening as it's happens when warm as well. All good point though. I will redo all piping and see where we go from then

[alexanderfoti]

I think I have sorted it. You were right with the air leak. I replaced all pipes with nylon braided rubber instead of the transparent stuff including the leak off pipe and I had no hot restart issues.

Additionally I had an issue when the engine was idling for long periods of time ie traffic, when it would act the same until I got moving again.

Idled for 10 minutes, no stalling. Happy days.