89 xr4

xr4 dies in gear, have replaced stator, swithboxes, high/low rev box and rebuilt carbs, run good in tank
but not in the lake. very stumped, help

Re: 89 xr4

When you rebuilt the carbs, did you check the timing when you re-installed them? Might need an adjustment.

Re: 89 xr4

yes, the carbs were first. then that did not help, so then stator, switch boxes and high/low rev box and timed, in that order again same thing

Re: 89 xr4

Is the engine in basically good shape, as in good compression?

Carb linkage synchronization is critical, as in all the valves begin to open at exactly the same time. When you're checking that, Allow a slight gap between the throttle pick up and the cam, then re-set the idle timing (middle screw) for good idle. Sometimes they like a little timing advance before throttle.

If the engine is in good shape, disconnect the advance/idle stabilizer module and retime max timing for about 21?, at least for a test run. The module could be flaky.

'nother item to check is that the exhaust relief ports are actually putting as they should. Plugged up with carbon will give you too much back pressure at 0 boat speed.

hope it helps
John

Re: 89 xr4

What's different between the tank and in the water?

Motion of the boat stirring up water and crud in the fuel tank?

Drain the float bowls, catch it and look at it, see what's there.