Throttle Surge?

[Doug Roy]

I am looking at a 1982 23' Tiderunner "pocket trawler" with a 60 hp Pices diesel (about 1,900 hours). (My mechanic says the Pices is made by Isuzu.) Engine starts right up and runs strong, 3400 rpm max. After about an hour on the test drive I noticed an occasional small increase in engine speed (about 200 rpms) that would last about 2 - 3 seconds before dropping back down. It only happens in gear with the boat underway. Could this be an indication of anything seriously wrong with the engine?

Thanks!

 

[QC]

Re: Throttle Surge?

Is it turbocharged? Could be chugging on some of its own oil. Doesn't necessarily have to be turbocharged. Could also be in the governor. Could be in the drive gear or propeller too. I am not thinking a spun hub as some might think, but if it's only a couple of seconds this could be a of ventilation issue. Hard to determine how serious an issue with any of them . . . would have to nail it down although eating its own oil can been very seriously bad.

 

[Doug Roy]

Re: Throttle Surge?

QC - No turbocharger. I see you are in S. Ca. The boat is in Redlands. Can you recommend anyone in the area to do a thorough mechanical survey of a diesel boat?

Thanks!

 

[QC]

Re: Throttle Surge?

Check your PMs.