help me revive this beast (Yanmar 4JHE on F39PH)

Engines, Drive trains, Propellers, Steering, Ground Tackle and other mechanical system

Re: help me revive this beast (Yanmar 4JHE on F39PH)

Postby rbpfyo » Sun Jul 12, 2015 9:00 pm

OK
back at the boat
loosened the 3 nuts that secure the injection pump (not easy)
with hard pipes attached to injectors and pump, there is very little play - pipes are simply too hard - don't flex, bend, or give
with pipes *detached* at the injectors, there is major rom for adjustment - at least 5° of rotation, maybe more
seems like the pump is designed to be timed statically with pipes detached - i.e. at 12°bTDC, injector #1 opens
then pump is tightened securely, *then* pipes are reattached
but I cannot get them to 'stretch' hardly at all to accommodate a significantly different timing setting
(with the pipes attached, but nuts loose, I can 'wedge' the IP a little more advanced, and it seems to run a little better, if I use my imagination
but I am making almost no difference to the timing
good news is, this is definitely how the timing is supposed to be adjusted
do I need a new set of pipes? is there more play when they are new? are there different size pipe sets? can they be bent or elongated on a bench?
I may need as much as an extra 1" of pipe
thanks for any thoughts
Rolf in MA
rbpfyo
 
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Re: help me revive this beast (Yanmar 4JHE on F39PH)

Postby rbpfyo » Mon Jul 13, 2015 1:53 pm

well, I did it this way:
detached hard pipes at the injectors; rotated the pump to advance it; timed the IP to match injector pulse on #1 with timing mark on the flywheel; manhandled the pipes a little bit to get them positioned over the injectors again; reattached
the good news is, it still runs
bad news is, not much better
same banging (maybe a little less ) and smoke (maybe a little less)
plus now there's a low throaty note I didn't hear before
question: is it possible that one bad injector could account for both banging and smoke?
would too advanced sound throaty?
vid to follow...
rbpfyo
 
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Re: help me revive this beast (Yanmar 4JHE on F39PH)

Postby rbpfyo » Thu Jul 16, 2015 9:56 am

finally got someone competent on the phone at Yanmar
confirmed that the pump turns clockwise from the *rear* to advance timing - i.e. away from the engine
based on the fact that I had it spun as far as possible to the right, and still timing seemed to be retarded (pulse was coming about TDC - spec is 12° bTDC), we surmised that the PO may have installed the IP one tooth off
didn't want to get under the gear cover, but seems like I have no choice - that's what I'll be checking Sunday
rbpfyo
 
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Re: help me revive this beast (Yanmar 4JHE on F39PH)

Postby rbpfyo » Mon Jul 20, 2015 9:04 am

well, spun the IP back hard clockwise (from the rear), per Yanmar tech - running well enough to get home - banging less, smoking not too much - I still think the IP gear is off a tooth, but looked at the gear case, and did not want to tackle it - so little room, and too many bolts to drop - not to mention repositioning the gear
calling the engine good enough
now on to other things - checklist for the 80 mi crossing back home (Hampton Beach, NH to Wellfleet, MA)
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Posts: 82
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