d03161 RECOMMENDED AIRCRAFT ENGINES SERVICE INSTRUCTION ENGINE START AT LOW TEMPERATURES AT ROTAX ENGINE TYPE 912 AND 914 (SERIES) Repeting symbols: Plese, py ttention to the following symbols throughout this document emphsizing prticulr informtion. WARNING: Identifies n instruction, which if not followed, my cuse serious injury or even deth. Denotes n instruction which if not followed, my severely dmge the engine or could led to suspension of wrrnty. NOTE: Informtion useful for better hndling. 1) Plnning informtion 1.1) Engines ffected All versions of the engine type: - 912 (Series) strting with seril production - 914 (Series) strting with seril production 1.2) Concurrent ASB/SB/SI nd SL More to this Service Instruction the following dditionl Service Bulletins/Instructions/Letters must be observed nd complied with: - Service Bulletin SB-912-037/SB-914-023 Instlltion of n electric strter with enhnced power current issue. - Service Instruction SI-912-012/SI-914-014 Routine modifictions of the Bing constnt depr. crburetor current issue. 1.3) Reson Reports from the field hve shown tht more informtion nd instructions bout cold strt in low temperture zones re necessry. One or more of the following could cuse the cold strt behviour to become worse: - Unpproved nd untested modifictions - Engine oil with viscosity clss tht is too high - Incorrect bttery or bd chrging stte - Worn or dmged electric strter - Cble cross-section to the electric strter too smll - Grounding from the engine to the ircrft frme tht is not sufficient - Lck of mintennce (especilly on the crburetor) - Worn sprg clutch - Improper crburetor-nd/or chokesynchroniztion - Incorrect, old or contminted fuel (especilly in the flot chmbers) - Improper idle speed (to low) - Friction torque in the bcklsh rnge of gerbox not within tolernce (should be djusted to the mx. llowed vlue). - Electrode gp in the sprk plugs too lrge - Trigger-coil clernce to the fly wheel set incorrectly - Incorrect propeller (moment of inerti too lrge) - Unsuitble engine suspension / non-neutrlized vibrtions WARNING: Consequent dmge becuse of possible kickbck of the propeller if there is flse strt cnnot be ruled out. Immeditely remedy these cuses. pge 1 of 5
1.4) Subject Engine strt t low tempertures t ROTAX Engine Type 912 (SerieS) And 914 (Serie) 1.5) Complince The procedures nd modifictions described in section 3 cn be done t the discretion of the owner. 1.6) Approvl Not required 1.7) Mnpower Estimted mn-hours: Engine instlled in the ircrft - - -mnpower time will depend on instlltion nd thuse, no estimte is vilble from the engine mnufcturer. 1.8) Mss dt Chnge of weight - - - none. Moment of inerti - - - unffected. 1.9) References In ddition to this technicl informtion refer to current issue of - Opertor s Mnul (OM) - Illustrted Prts Ctlog (IPC) - ll relevnt Service Bulletins (SB) - ll relevnt Service Instructions (SI) - Mintennce Mnul (MM line/hevy) 2) Mteril Informtion 2.1) Mteril - cost nd vilbility Price nd vilbility will be supplied on request by ROTAX Authorized Distributors or their Service Centers. 2.2) Compny support informtion ROTAX does not py lbor rtes nd chrges for prts for rework or retrofitting. 2.3) Mteril requirement per engine Fig.no. New prt no. Qty/engine Description Old prt no. Appliction ( ) 888803 1 CD-crburetor ssy. 1/3 888802 type 912 A/F/UL ( ) 888808 1 CD-crburetor ssy. 2/4 888807 type 912 A/F/UL ( ) 888374 1 CD-crburetor ssy. 1/3 888373 type 912 S/ULS/ULSFR ( ) 888379 1 CD-crburetor ssy. 2/4 888378 type 912 S/ULS/ULSFR ( ) 887094 1 CD-crburetor ssy. 1/3 887093 type 914 F/UL ( ) 887099 1 CD-crburetor ssy. 2/4 887098 type 914 F/UL NOTE: The modified choke rotry disc vlve is used strting from the following engine numbers: - 914 F from S/N 4,420.412-912 UL from S/N 4,406.138-914 UL from S/N 4,418.634-912 S from S/N 4,923.038-912 A from S/N 4,410.629-912 ULS from S/N 5,643.465-912 F from S/N 4,412.868-912 ULSFR from S/N 4,429.962 NOTE: This modifiction ws introduced in seril production strting from crburetor S/N 04/0001. 2.4) Mteril requirement per crburetor Fig.no. New prt no. Qty/engine Description Old prt no. Appliction (2) 261271 1 choke rotry disc vlve. 1/3 261270 crburetor (2) 261276 1 choke rotry disc vlve. 2/4 261275 crburetor (1) 268762 2 jet 105 n.. crburetor (1) 268857 2 jet 120 n.. crburetor (1) 268763 2 jet 130 n.. crburetor (1) 268765 2 jet 140 n.. crburetor pge 2 of 5
2.5) Rework of prts The choke rotry disc vlve (2) before seril production introduction (see chpter 2.3) cn be reworked s described in the instructions chpter 3.2.3. 2.6) Specil tooling/lubricnt-/dhesives-/seling compound - Price nd vilbility Price nd vilbility will be supplied on request by ROTAX Authorized Distributors or their Service Centers. Prts requirement: Fig.no. prt no. Qty/engine Description Old prt no. Appliction (2) N.B. LOCTITE 221 899785 choke housing In using these specil tools observe the mnufcturer s specifictions. 3) Accomplishment Instructions All the mesures must be tken nd confirmed by the following persons or fcilities: - ROTAX -Airworthiness representtive - ROTAX -Distributors or their Service Centers - Persons pproved by the respective Avition Authority - Persons with type-specific trining (pplicble only for non-certified engines) WARNING: Proceed with this work only in non-smoking re nd not close to sprks or open flmes. Switch off ignition nd secure engine ginst unintentionl opertion. Secure ircrft ginst unuthorized opertion. Disconnect negtive terminl of ircrft bttery. WARNING: Perform work on cold engine only. WARNING: Should removl of locking device (nmely lock tbs, self-locking fsteners) be required when undergoing disssembly/ssembly, lwys replce with new one. NOTE: All work hs to be performed in ccordnce with the relevnt Mintennce Mnul. 3.1) Occsionl low temperture opertion When strting n engine t low temperture proceed in ccordnce with the current Opertor's Mnul, Section "opertion in winter time". NOTE: The turbo engine 914 needs bit longer wrming-up period. Therefore this engine hs to be run wrm with fully open choke t pprox. 2000 r.p.m. After few minutes wrming up close the choke pprox. hlf nd try to increse engine speed slowly. If the engine does not respond to the throttle, go bck to idle nd open choke fully. Repet this procedure until engine rects willingly to throttle ccelertion. Continue wrming up ccording to the current Opertor's Mnul until the oil temperture hs reched 50 C (122 F). 3.2) Permnent opertion t low tempertures For engine strt t low tempertures different strt jet nd modified choke rotry disc vlve (2) is recommended on both crburetors. Therefore the fuel-ir mixture is highly enriched t the strting phse nd throtteled down by the dditionl middle setting t the wrm up phse to get smooth engine opertion. 3.2.1) Exchnge of strt jet (see fig. 2) The strt jet (1) (jet 85 stndrd jet system) in the flot chmber (3) must be exchnged for n pplicble lrger jet (1). Jets of the following sizes cn be selected depending on the usul tmospheric conditions nd the cold strt behviour of the engine: Jet 105, 120, 130 or 140 (see chpter 2.4). NOTE: The jets (1) re selected by tril nd error, but it must be noted tht the fuel-ir mixture cn be highly enriched nd cn led to fuel over-enrichment in very bd cses. 3.2.2) New choke rotry disc vlve (see fig. 1 nd 3) When using lrger strt jet (1), the new choke rotry disc vlve (2) with chnged ventiltion bores (5) must lso be used. This mkes it possible to operte the engine t middle setting of the cold-strt system during the wrm-up phse nd thus get smooth engine opertion (strt of seril production, see chpter 2.3). pge 3 of 5
3.2.3) Rework of old choke rotry disc vlve (see fig. 3) After removing the choke rotry disc vlve (2), the ventiltion hole (5) of Ø 0.65 mm must be redrilled to Ø 1 mm. The rotry disc vlve chnnel (6) must be fully clened of chips fter the mchining! WARNING: Only uthorized distributors nd qulified technicins re permitted to crry out the crburetor clibrtion. Alwys use crburetors of identicl jetting only. Never clibrte the two crburetors differently. If returning to flight opertion t wrmer conditions the crburetor hs to be converted bck gin to the stndrd jetting. Otherwise the mixture would get too rich t engine strt, possibly cusing vibrtions which could led to engine stop. Non-complince with these recommendtions could result in engine dmge, personl injury or deth! - Restore ircrft to originl operting configurtion. - Connect negtive terminl of ircrft bttery. 3.3) Test run Conduct test run including ignition check nd lekge test. 4) Appendix The following drwings should provide dditionl informtion: fig. 1 open closed middle open middle closed 05768 Approvl of trnsltion to best knowledge nd judgment - in ny cse the originl text in the Germn lnguge nd the metric units (SI-system) re uthorittive. pge 4 of 5
fig. 2 2 1 A 3 A 05769 fig. 3 Ø 1 mm (di. 0.040 in) Ø 1 mm (di. 0.040 in) 4 6 5 6 4 L R 2 crburetor 1/3 crburetor 2/4 5 05773 NOTE: The illustrtions in this document show the typicl construction. They my not represent full detil or the exct shpe of the prts which hve the sme or similr function. Exploded views re not technicl drwings nd re for reference only. For specific detil, refer to the current documents of the respective engine type. pge 5 of 5