yamaha 40 autolube popping through exhaust

[julian0792]

Hi chaps,am in need of some help pls, I have a 40 autolube its a 1994 model 6h4 and it has been laid up for several years.I have cleaned the carbs out and replaced the impellor.It starts on the button a goes straight to fast idle for around twenty seconds then drops to tickover.If I rev it when its on tickover it will either cut out or pop from the exhaust.If I rev it while its on fast idle it seems to rev up normally apart from an occasional little pop.This problem is really starting to annoy me now so any help would be good. Thanks julian

 

[99yam40]

check to see what the timing is doing when this all takes place

 

[julian0792]

How do you recommend I do this please.

 

[tommarvin]

Welcome, some thoughts, the motor has been laid up for several years, I would clean the carb(s) with carb cleaner and blow all openings clear and clean, the get carb rebuild kit with all new gaskets including the gasket between the carb and carb adaptor.
For some reason,cleaning and rebuilding carbs is not that easy, " I just cleaned my carb now it's messed up" Watch you-tube videos until you feel comfortable.
Good for you replacing the impeller, I would change the lower unit gear lube with all new factory seals for fill and drain.
Drain and clean the autolube,tank and hoses, install a new filter.refill, make a line on take to make sure oil is being used and going down.
I think 99yam40 means get a timing light and check the timing, If you don't know how get a friend,or watch you-tube videos about timing it complicated if you have never done timing before..

 

[julian0792]

Ok thanks will order up a carb kit.I have been googling the fault and am getting allsorts of ideas put in my head such as lower crank seal and seized rings.It seems odd that it revs up OK when it's on fast idle.I have a couple of videos of the fault but don't seem to be able to upload them.Where would you recommend the best place to get the car kits from .Thanks Julian

 

[99yam40]

How do you recommend I do this please.

Use a timing light to see if you idle timing is in spec along with the WOT timing when running on the water.