Carburetor pick-up timing ???

[txislandguy]

I have a 1998 S200TXRW. Engine starts and runs great, then when I come of plane and need to throttle back up the timing seems to be off. If I push too much throttle the engine will die but would start right up. So I just put the throttle in gear, as if i was going thru a no wake zone. After a minute or so at this speed I'll slowly add throttle and if it bogs down again I'll pull back on throttle and just putt-putt along. Eventually slowly adding throttle the engine timing begins to catch up then it runs great with no issues until I come off plane again and have to go thru the same procedure. The longer I run up on a plane directly relates to how long I will have to putt-putt along until engine will allow me to jump back on a plane. Long run (30 min.) may take 15 minutes, short run maybe 1 or 2 minutes....for a car analogy it's like someone was turning the distributor while timing a car, slowly getting bad to good.

Replaced the fuel pumps and throttle roller which did not help. WOT timing and idle timing are correct.

Thanks for any insight you may have.

[99yam40]

If you think it is timing, then monitor it when this happens to prove it is or is not timing changing

[txislandguy]

Great idea but not sure how I could monitor the timing while underway.

[amahaork]

Check timing settings according to service manual. Make sure it is correct. After that check fuel pick up tube in gas tank.

[99yam40]

Great idea but not sure how I could monitor the timing while underway.

with a timing light just as you would while it is sitting in the drive way or at dock.

But timing being off (not advancing as it should) would/should not cause motor to die

[zenoahphobic]

Great idea but not sure how I could monitor the timing while underway.

You haven't given any reason why you think it is timing, because you say it is
OK at WOT.
If you didn't back off WOT does the engine perform as it should? If not you have a fuel issue. It seems (and we aren't there) the engine runs better after a while suggests momentary excessive fuel (too rich) to be the problem. High pump pressure when running fast reducing when throttling back suggest a leak in the needle seat. Once pressure drops it seals properly. Can't suggest much else other than, if you want to go down ignition advance route, check what happens with linkages pulling forward and then pushing them back with the throttle. Loose or what? Please report what you have found.