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Some notes on the 1GM10 engine
I have put this on as a working set of notes I have been compiling - rather than all on scraps of paper ! I'm looking onto rebuilding the engine next year - so sorting out sources and possibilities ! I say again about the online Ribparts site, It really is the most useful parts site for Yanmar engines. The entire elecronic parts catalogue for all engines - use it with IE and download 'Isoview' and you can see all the exploded drawings as well. ( all java of course but you do know about the 'print screen' button ? if not | see here ) Its just as I compliled it - so nothing special, but its up to date for resources ( I'm doing this now Jan 2014 ) Yanmar Engine Rebuild equipment General - only special tool for stripping crankshft and canshaft - 36 long reach crank socket ( main nut holding on the governer weights and crank gear ) Crankcase solid bearings need pressing out - but only front end is captive in block - rear flywheel end has removable bearing housing.( ie Crank just lift out once housing is removed ) The camshaft has front ballbearing race held in place by a small screw - and the rear appers to just sit in a housing in the block ? No mention in the workshop manual about any removable bearing face there - seems odd ? I would have thought the front crankcase solid bearing face could stay in situ for any rebore work ? No flywheel puller needed - five bolt flat face mount. General puller for fanbelt pulley - ( ie toolstation - or below ) They do recommend a ridge reamer for removing the piston upwards - but if new rings at least are being fitted - then I think the piston would come out - without prior reaming ? (maybe check this ) Cylinder would be honed at least anyway with new rings. Need Micrometer set - see Chronos below and bore gauge. Maybe these could be hired ? Cheap enough - nice to have
Crankcase nut - spec at 36mm - max 49mm - open long reach 140mm http://www.williamstools.co.uk/melco-tim9-iso-metric-box-spanner-36mm-x-41mm-x-175mm-7--tim9-30519-p.asp @ £ 26.00 also http://www.thomasmeldrumltd.co.uk/Pages/TubularBoxSpanners.aspx Thomas Meldrum Limited Tel: 0114 2725156 TIM.9 - 36 x 41 - 7 - 175 - @£16.88 - plus vat Bore Gauges http://www.machine-dro.co.uk/catalogsearch/result/index/?p=2&q=bore+gauge Micrometers Cheapest from sound source - Chronos Ltd ( yanmar recommend 4 - 0 - 100mm ) Related Parts sources French Marine really know what they are talking about.01206 302133 Rollo - can get anny part within a week. Keyparts cheap( but often aftermarket on gaskets etc ! ) free postage. RibsParts - access to online EPS dealer style database, Using IE and download of Isoview - you can see all the exploded Yanmar parts drawings - superceeded parts etc - for all models. Extremely useful - shame it only works with IE for online sales and drawings. Also Marine Power - and others. Note Oversized piston and rings are available - as specified in the manual, but do not show on the general dealer database ! Keyparts accessed the documentation they have to confirm this. Its listed on a supplementary sheet, which appears not to be digitised - ie its on paper ! Part no - 105325-22570 piston and rings +.25 - 1GM10 105225-22570 - rings +.25 only. seems there is also .50 rings listed but manual says not to bore over .25 ? Part Nos Valve guides - inlet and exhaust 128170-11160 valve spring retainer caps - 104200-11180 cotters - 27310-070001 Valve exhaust - 105225-11110 Timing shim set(under the inejctor pump) about £10 - 104271-01950 Pre Combustion chamber lower packing x 2 124950-11450 Rocker gasket - 128170-11310 Valve stem seals - 12870-11340 Water pump bearings - Koyo 6000 CM 01215 ( stocked at Simply Bearings - about £2 ) Small seal - NOK AE01451 dims 8 - 18 - 7 inner, outer, depth Large seal - SD 8 - 22 - 7 ( simply bearings have sizes - but not the same make ) - cheap, They are available from Yanmar - dear ! Circlips - large, 26 - thick 1.7mm - small ( between the bearings ) 10mm 0.94 Alternator bolt(M8x120 ) 26106-081202 Oil Pump rotor assb - 728170-32500 - £76.00 Part - Cost Approx retail, bottom end Crank main bearing - oil seal 21.00 - main metal ( housing bearing) 20.00 Camshaft ball race - £12 oil pump rotor - £76( but not recommended - rotor only ! - new oil pump pricey - 200 plus - check that one ) Gasket set - French marine, £95 inc vat( check whether this is Yanmar ) Oversized piston and ring - £150 note - circlips are available as parts for water pump - £1 or so Specs ( mm ) Bore specs - measure NS/ EW and at 10.5 - 105.5 down and middle. Diam standard - 75.00 - 75.03 - wear limit - 75.10 Out of round - standard - 0.01 - wear limit 0.02 Note - bore diam should not exceed 75.10 - but not sure on differences between top and bottom - when out of round is in spec ? ie 75.05 bottom - 75.10 top ? ( need to check this out ) Block - 'out of flat' - limit 0.05 ( head - 0.07) Piston - with gasket off, should be above block approx 0.6mm tdc( rough figure) - Old gasket clocked at 1.35 thick. Top clearance - Spec - 0.68 - 0.88. Valve seat width - spec 1.77 - no wear limit specified. Note that too wide is not good. ( Note - my engine - 1st strip down on head, seats clock at 1.85 before any lapping. With a good lap in on the exhaust - barely much wider - maybe 2mm ) Yanmar say if the seat is reground( as opposed to lapped ) - a shim should be placed under the valve spring. Presumeably to correct spring tension ? Valve head recess/ Spec - 0.95 - limit 1.25 ( valve head below head surface) Valve tilt value - max 0.036 ie valve on flat plate against a square. Max gap against square, top or bottom at any position = B. Height of free length of spring = A . Tilt value = B/A - Note - 1.4mm 'lean' off square = 0.036 approx. So old rule of 'about a 1/16th' out of square as max lean look good info. Mine are 1.4 mm off - so I may fit new springs ? Put text in individual divs Images as placed - no div - max width 788. |