tacoma_2002
Cadet
- Joined
- Jan 24, 2012
- Messages
- 11
I have a 20hp Johnson CRESB (1990) that I've had for about the past 10 years. Ive recently experienced some weird issues with it.
It funs fine at idle, mid throttle and WOT....until you idle the engine for lets say 5 minutes or so. Then when I try and open it back up it seems like it hits a sort of 'rev-limiter' and shakes wildly..almost if the fire has been cut off and then back on...off then back on....etc. Imagine you have your engine running out of water with 'ears' on. The sound it makes when you rev it up past half throttle and idle it back down quickly...the wah-dah-dah-dah (lol i know) sound it makes as it winds down...that the only thing I can make this thing do after it idles for a bit, in water.
Carb is clean and I installed a new fuel pump last season. It has ran fine up until the last couple of outtings. The butterfly is perfectly level at WOT and I just replaced the primer bulb and have put 3 different types of plugs in it (L77, NGK, and Gapless Champion) with no different results. I'm getting a good spark on both cylinders out of the water at all RPM's but I have not yet tested them when the problem occurs (mainly because it's at the most inconvenient times
)
I can play with the throttle a bit (choke does not help this matter), cycling from idle to WOT, I can finally make it open back up and run WOT. I can idle it for...lets say a minute or two....with no ill effects. Its just the 'extended' idle time that it wont open back up.
I've ran engines that have fouled a plug on one cylinder and ones that have had stopped up jets, however, this is not the effect I'm getting so I'm lead to believe it is a Ignition problem elseware. Sorry if this has been covered but I searched for the past couple hours with no luck...
Thanks in advance!
-Andrew
It funs fine at idle, mid throttle and WOT....until you idle the engine for lets say 5 minutes or so. Then when I try and open it back up it seems like it hits a sort of 'rev-limiter' and shakes wildly..almost if the fire has been cut off and then back on...off then back on....etc. Imagine you have your engine running out of water with 'ears' on. The sound it makes when you rev it up past half throttle and idle it back down quickly...the wah-dah-dah-dah (lol i know) sound it makes as it winds down...that the only thing I can make this thing do after it idles for a bit, in water.
Carb is clean and I installed a new fuel pump last season. It has ran fine up until the last couple of outtings. The butterfly is perfectly level at WOT and I just replaced the primer bulb and have put 3 different types of plugs in it (L77, NGK, and Gapless Champion) with no different results. I'm getting a good spark on both cylinders out of the water at all RPM's but I have not yet tested them when the problem occurs (mainly because it's at the most inconvenient times
)I can play with the throttle a bit (choke does not help this matter), cycling from idle to WOT, I can finally make it open back up and run WOT. I can idle it for...lets say a minute or two....with no ill effects. Its just the 'extended' idle time that it wont open back up.
I've ran engines that have fouled a plug on one cylinder and ones that have had stopped up jets, however, this is not the effect I'm getting so I'm lead to believe it is a Ignition problem elseware. Sorry if this has been covered but I searched for the past couple hours with no luck...
Thanks in advance!
-Andrew