Rebuilding a 2006 Yamaha VZ225 TLR(HPDI): write up and photos

[reellittlephish]

More on the clean spots of the piston
Charlie is right. Under certain conditions when thicker chunks of carbon are stuck to the piston they can create hot spots and uneven heat distribution on the piston. These spots can glow and can cause pre ignition leading to piston failure. Most of the time these thicker carbon spots will get hotter then the rest of the piston and simply flake off. Some will disintegrate and some may get stuck in the ring. Rich injectors are not always good.

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I've been studying. This is the first 2 stroke rebuild in a long time. The last one I was over 35 years ago. Everything is off the cylinder block and it goes to the machine shop on Monday.


Sunday Feb 26


Rigged the motor so I could lay it on it's side to remove the large 36mm nut, balancer and seal housing. Then removed the crankcase. I found metal shards around the edge of the main bearing adjacent and rear of #2 cylinder. Numbered #2 connecting rod.


Tuesday Feb 28


Marked pistons for number and orientation. Market connecting rods for number and orientation. Removed pistons and connecting rods. 8 mm 12 pt socket required. Ended up getting a socket from Snap On. Removed one main bearing. Removed all remaining external attachments and senors from cylinder block. Seal rings are still in place. Had to easy out last screw...need metric replacement. Removed engine temperature sensor. Removed crank position sensor; 2 screws into a plate. Removed 4 or 5 short bolts which were ground lead connectors. Used a dial caliper to check diameter of one main bearing; was within spec. Use a feeler gauge to check rod end to crankshaft clearance: all were within spec. Removed the starboard and port stopper assemblies. Removed anode covers and left the anodes in place.



Wednesday March 1
bought some Muriatic acid.

Crankshaft Journal Diameter: 2.3219 – 3.3225” or 58.975 – 58.991 mm. I'm measured at 3.3225" on both journals.



Thursday March 2


Will take the cylinder block outside and scrub the contaminated cylinder. Scrubbing successful. Removed second main bearing. Looks OK but will replace both main bearings. Removed one sealing ring but total removal does not seem necessary. Will have the machine shop check the crank for run out when I take the cylinder block in for honing or re-bore.


Friday March 3


Got some parts cleaner and soaking a piston. I'll clean it and use to to measure the inside diameter of the cylinders with the digital micrometer.

[DaleHollar1]

Was you able to find a marine block shop? Below is a link to a dealer on eBay for engine kits. I wouldn't worry about cleaning block. You will need to get the block washed by whoever bores or resleeves it.

Look at this on eBay:


https://www.ebay.com/itm/122045410252


WSM YAMAHA 225-300 HP 3.3L HPDI PWHD REBUILD KIT 100-295-10 OE 6D0-11636-02-00

Donald

[reellittlephish]

Thanks Donald. I bookmarked it. Measured the tops of the cylinders and they came in at 3.661 to 3.662" with my dial calipers. My bore gauge skills are not up to consistency so I'll wait for the machinist. If the crank is within limits for out of round and the cylinders can be honed or bored...time to order parts and send the injectors off.

This is mostly an automotive machine shop but they do work for my Toyota mechanic and for Las Vegas Marine. I printed out the specifications and will take the sheets to the machinist. I'm hoping all that will be needed is honing.

I rewashed the #2 cylinder today and got more of the aluminum smears off; no longer looks like this photo.

Yesterday I filled the Tacoma and realized i'be been using 87 Octane in the Yamaha. I add Stabil Marine stabilizer and about 3 to 4 times a year treat the tanks with SeaFoam. The Skeeter fishes all year so there has been no winterizing. My old 115 Yamaha I decarborized a couple times a year by pulling spark plugs and spraying Sea Foam into the cylinders then a ride to the launch (45 minutes) and running around for 20 minuteI've never done that with this VZ225. I have neglected the filters...no change out in at least 4 years until recently. While trying to figure out what was wrong I changed the big seperator filter in the take..there was no water or debris in that filter.

[DaleHollar1]

Good job

[reellittlephish]

Fultz machine shop says a rebore is required. He's not sure if he can get a clean job one over size or not. He is doing a test bore at one size over. He suggested I bore the one cylinder oversize and leave the reminder of the cylinders alone with a honing. A single cylinder rebore is about $250 and boring all 6 is about $800. Cost wise is there much difference buying a piston rebuild kit versus buying pistons separately? Pros and Cons again please.

For instance if I could get a kit for about $400 less than buying separate parts I'd be more inclined to have all cylinders bored the same. I called SIM Yamaha this morning. Waiting for a call back. They only sell individual pistons; no kit. Wiseco has piston kits and the ebay link (WSM) shows piston kit sizes to 0.040. I did a "back of the napkin" calc and got to about $430 difference

[DaleHollar1]

You can find individual pistons and such on eBay. Happiemac and the one I sent you link for I have bought from before. That seams really high to bore. You may come out better off shipping it out.

[Rich Z]

Don't buy the yamaha pistons. Look up WSM pistons and get with Chis Carson Marine. He can get you a rebuild kit. No way I would pay that machine shop the price they asking.

[reellittlephish]

Thanks for the input on boring costs. I'll talk to the machine shop tomorrow. Thanks also for the links.

[jdwo2212]

I second what Rich says. Thats exactly what i did with my 250 hpdi. Chris carson will do your machining for a lot better price and someone who works on these motors often. Also sent me a full rebuild kit with wsm pistons. Powerhead is being rebuilt at my local shop. But Chris was an incredible help with parts and info. Call him. You wont regret it.

[Charlie206]

Good advice to call Chris. $250 per hole is nothing short of robbery.

[reellittlephish]

Took your advice and recovered the cylinder block, crank etc. Now packaged for a trip to Florida.

[jdwo2212]

Good idea. He is sure a very helpful person! I might call him tomorrow just to say thanks again myself.

One question though....the cat looks like it wants to go along.... Did ya send the cat????

[reellittlephish]

Nastasha is about 8 months old. Total "Miss Curiosity"; she was under the cardboard flaps but I couldn't get a good photo.

[jdwo2212]

Funny.

[Jaharr206]

I pay 30 bucks a hole for boring. That price is insane. And like rich said do not put Yamaha Pistons back in it.

[reellittlephish]

I pay 30 bucks a hole for boring. That price is insane. And like rich said do not put Yamaha Pistons back in it.

Package scheduled for arrival in Key Largo today. If everything goes well, I'm having the machine shop supply the piston kit and gaskets etc. I'll re-assemble myself back in Las Vegas.

[reellittlephish]

Good news is the cylinder block is on it's way back from Florida and only required a 0.25mm overbore.

Vegas had wind last 3 days and yesterday winds were clocked at 75mph at the nearby airport. I checked the Skeeter this morning (it has the last vestiges of a cover on it) and realized the lower cowling had moved out of position; probably moved by the strain in the boat cover which covers the upper cowling.

Totally my fault. I had a friend helping during the engine lift and he unbolted the lower cowling. I didn't catch it till later and neglected to refasten. It could have been very bad. As it was I was able to salvage the seal. I had to find the bolts which were not bagged and labeled; do some online research to be sure I had the correct ones. Yep... they had red loctite on them.

Got out the stationary grinder; put on the wire wheel and the motor didn't want to turn. By this time, it's a good thing no one was around. I tinkered a bit and manged to get the grinder turning. Brushed the bolts and then I couldn't find the red loctite. At that point you gotta know when you're whipped. Least I got the cowling re-bolted and the cover back on secure for tonight cause it might drizzle again.

Always keep an eye on the help.



There is a lot of calcium build up on the motor area which is usually covered by the apron. While things are open I thought I could clean the build up off with some muriatic acid. Anyone ever done that?

[ChrisCarsonMarine]

No acid! Aluminum is a self protecting metal,forming a shell of aluminum oxide,that will slow or stop the corrosion.Cleaning it off allows more corrosion to eat more aluminum until the protective layer is back.Anyway,while muriatic dissolves rust on iron,with aluminum it's a little like pouring boiling water on a stick of butter,Chris

[shallowhal]

any updates on this one?

[cwilt]

I have been watching this one...