115 hp. '98 in-shore B115TR ... questions

[spete]

4 questions:<br /><br />Wondering how one tells wether or not a cylinder is taking on water from an internal source, bad gasket, etc. From what I've read you can look at the plugs and if you find one that looks lean/dry that could indicate a problem- I'm concerned that my boat has been idling poorly even after a carb rebuild, it's a '98 model with a good amt of hours and used primarily in salt water. Also, looks like there's some water vapor - more so than usual - in the exhaust. I can see some salt creep on the visible gasket material when looking at the power head?<br /><br />Is there any way the water control valve could be clogged and causing a warmer idle temp that could affect idle mix/burn?<br /><br />Looking at replacing the Water Pump impeller on this model which came standard with a low-water pickup/larger lower unit. Is there anything special i should know about attempting the impeller replacement on this model?<br /><br />Are there any sources online where I can order the proper impeller kit and are there any special gaskets/sealants i should know about?<br /><br />Thanks for your response!

 

[spete]

Re: 115 hp. '98 in-shore B115TR ... questions

Hey Rodbolt ... I know that you're the Yamaha guru on this board. Wondering if you'd mind taking a look at the Q's i posted and tell me what you think - Thx SP

 

[rodbolt]

Re: 115 hp. '98 in-shore B115TR ... questions

hello<br /> spete<br /> Im no Guru<br /> I just fix them.<br />on your water pump. buy a complete kit from yamaha. have you ever changed an impeller on an outboard before? if yes tell me what model and horsepower. I am trying to get a feel for your technical level before I tell you anything that will be confusing. the hardest 2 things on doing a pump job on that motor, if the bolts dont snap off, is removing the drive shaft retainer cup and spacer and removing the old impeller drive key. do you have a service manual? if so what brand?<br /> as far as the idle when was the last time it idled ok and why did it start idling bad?<br /> answer me some and I will answer you some <br />good luck and keep posting

 

[spete]

Re: 115 hp. '98 in-shore B115TR ... questions

Thanks for getting back to me on this ...<br /><br />I've taken down a 25 hp Sportster and rebuilt it with a Clymer manual with decent success (pretty simple job) and have rebuilt the carbs on the 115 Yamaha using the Clymer manual. I'm pretty confident in my abilities with a wrench if the steps are clearly laid out. I've never changed the impeller before and am a bit uneasy about getting it all sealed back up properly. Idled noticably better right after the carb rebuild and has gradually gotten a bit worse. I checked the plugs yesterday and they all look black around the plug base and reasonable dry/dark on the electrode. I am using NGK plugs.

 

[spete]

Re: 115 hp. '98 in-shore B115TR ... questions

(continued ... accidentally hit send) I did try a couple of gallons of SuperTech from Wallyworld and that's about half done. Have always previously run Yamalube and Ring Free in the past. Based on feedback from folks on this forum I decided to give it a try. Might be part of the issue. On the last trip out I got some sand/grit in the intake and the pee hole got clogged and i unplugged it - my pressure guage never got back to normal at idle but was fine at running RPM's - never overheated - just started running poorly. I figured that the grit finally broke down the impeller so that it's now not being efficient at low RPM's but still works okay at running speed? I check the springloaded water pressure valve yesterday and it look pretty clean and worked smoothly (black plug w/spring). Let me know what else you need to know. I have noticed as i mentioned earlier some salt creep on the gasket material - especially on the starboard side down at the base of the power head where it meet the lower part of the cowling. Thanks for taking a look at this.<br /><br />SP

 

[spete]

Re: 115 hp. '98 in-shore B115TR ... questions

bump >>>> to rodbolt

 

[rodbolt]

Re: 115 hp. '98 in-shore B115TR ... questions

hello<br />well on the spark plug question. your first indication that the engine is burning saltwater is tiny green spots on the electrodes from the minerals in the salt.<br /> second is the plug will look steam cleaned <br />third is you will have a total piston failure and water on the spark plugs. if you suspect head gaskets pull the heads and be done with it. the head gaskets are the same materiel for all engines.<br /> for the water pump follow the service manual and remove all the bolts including the one under the trim tab. dont forget the speedo sender if used.<br />how with the unit secured in the upright position unbolt and remove the pump housing. if the insert cup came off with the housing remove it from the housing and reinstall it on the impeller by pusing it down while rotateing the shaft clockwise.. now is the interesting part. starting in 95 yammis used a retainer to hold the driveshaft up at idle and nuetral.<br />to remove the retainer I use 2 large screw drivers pressed between the sttel cap and the nylon clip. twist them as you pry. if it moves and stops you willhave to pull up on the shaft and tap the steel back down again. ok now the retainer assy is off remove the impeller and cup. on top of the impeller is 3 sttel rings 2 flat and 1 wavy. save theses and on reinstalling it goes flat wavy flat. I use a chisel and place the cutting edge at the top of the keey and tap downwards and drive the key out. then remove the plate and gasket. if the rubber dam at the back of the pump on the fwd edge of the exhaust cavity is corroding remove it and wire brush it or it can cause cooling problems by wedging the plate and gasket up slightly. ok now install the gasket and plate. now drive in the key with an aluminimum or brass drift then the impeller then the flat ring wavy ring and flat ring now the plastic then the steel cap. now pull up on the shaft while tapping down and locking the retainer. now put the small oring in the pump hsg then the insert. now grease up the large oring groove and install the large oring. now install the housing to the impeller while rotateing the shaft clockwise. now install the bolts and have a cool refreshing beverage. now install the unit making sure it and the shifter is still in nuetral. now bolt it all up and have another <br /> good luck and keep poisting hope this helps now I gotta go fix dinner

 

[spete]

Re: 115 hp. '98 in-shore B115TR ... questions

Mighty fine reply. I'm guessing I'll be needing more than two cool refreshing beverages when all is said and done. Looking forward to getting into this one. Do you recommend a large vise with wood on the inside to support the unit while working on it or do you use a special outboard stand ... suggestions? Should I also do the propeller shaft seals as long as i have that lower off? Thanks for sending along some detailed info to help make the job go smoother. Will keep posting .... SP