Forgot pull reeds and check

I found 3 issues with the front brakes which are now fixed.

1. The master cylinder was caked with grime around the little rubber pistons. Pulled it all apart and cleaned carefully. The rubber pieces seemed to be OK so I figured what the hey put it back in.
2. It took forever to bleed the front brakes. I spent a good 30 minutes bleeding and re-bleeding. The lever only improved slightly.
3. With all the bleeding, I noticed a noise coming from the front every time I pressed the lever. I pulled the hubs, and though the brakes are worn down they still have meat on them; but there are two adjustments at the bottom of EACH set of brake shoes. It was pretty easy to adjust them. I first removed the phillips head screw from the bottom, and just turned each of the 4-total 'cogs' about an 1/8 of a turn at a time. I was done when it was really hard to get the hubs back on over the pads, but once they are on they turn smooth. This improved the brake action and lever the best, and I can now lock the front wheels from spinning very easily and have plenty of left-over lever strength. This pilot will probably stop on a dime now.

The rear left tire blow out was actually a weird thing. Something got wedged between the rim against the suspension components, and put a 1/4" dent in that rim at the bead, about 1/16" deep. It was enough to break the bead and lose all pressure. I'll need to get the tire un-mounted, then carefully tap that dent back out, then probably use some juicy tire bead compound to keep her on. I actually may just have both rears re-mounted so I get new valve stems and nicely re-done beads.


I'll probably pull the carb within the next few days as I won't be able to ride anyways for at least the next 2 weeks. Gamling? Maybe... but usually any maiden voyage is going to have some issues. Honestly I didn't think the machine would get out of the parking lot; but it did, and it was awesome. I should be able to pressure test it once I get the carb off and the exhaust.

I am into 2-stroke stand-up jetskis, and I have a 2-stroke Engine builder as a friend just a couple miles away from me. He has very nice expensive boring machines, sleeve press, multiple honing tools, and had been around for decades with regaurd to porting cylinders (For watercraft mostly). He builds $10k engines for the competitive professionals. Paul Lehr from Lehr Performance Watercraft.

The intake and reeds are good on this machine. Its got new vForce3 reeds.

Piston

I'm a stand up guy as well. Yahama
The yahama is a hard one to port. I maintain .040 with revised squish band area ratio.
With the speed design the advertised cc is gasket based. Be careful there.
I have cc'ed and ran the angles.
So check your head gasket area and crushed thickness for calc.
Piston to me looks normal for application.
Heck for fun do a plug chop under load next time out. Post up in plug chop post. Before any Engine work.
Jetting specs to would be cool.
Thanks for pic.
Enjoy your ride.

Some port matching with a boost port mod will straighten out the flow. Show that to your Engine builder.

Yeah, I was just asking about the race fuel because that's what he said he was going to run.

"With the speed design" You mean KFab design?

Yep I run 100% vP racing c12 race fuel with Klotz r50 at a 40:1 mix and the pilot is going to be fed the same. On my carbon jetski I run a Dasa 865ss at 225psi (240psi w the power valve not-lifted). Thing rips. So does this pilot.

"So does this pilot." - nice!

I bought a portable mini tire mount tool from Harbor freight today. It worked quick and great for busting the rear tires off their beads. I did need to make a few quick adapters out of some loose 2x6 wood I had laying around - as the rim's hub is much larger than the tool can handle. The wood pieces were used like huge washers against the wheel.

Harbor freight had it 25% off today so it was only about $35
https://www.harborfreight.com/mini-tire ... 61179.html

I should have bought this thing YEARS ago. It can possibly do maybe a 14" tire.

If I ever go on a long trip and am unsure of what to expect I'll be able to bring the tire changer with me. I also bought about $20 worth of tire changing consumables as well as bead compound. My left rear popped off the bead due to having a couple small dents in the rim, which I heated and banged out flat while in there. The the right tire was also almost out of air today. Same thing - leaking at the bead. Both wheels were caked with mud wedged up in the bead.

So I was able to fix those issues and check my rear knuckles while the tires were off.

Tonight I had a couple hours and so I decided to pull the carb out, because the carb looks very wet today, after the run yesterday. The biggest issue: After dousing the entire carb in the buckets of cleaners I un-screwed the 17mm drain bolt from the bottom - and found NO O-RING at all. Completely vanished into thin air. Not even a crusty remain. Only dried up mud.

The story got much better from there. I could not really find anything else wrong inside the carb at all even though the carb was very dirty. The dirtiest internal part was the fuel inlet just before the needle/seat but its clean now. All passages were free and clear and everything just needed a good cleaning. Of the parts which came with my pilot - 2 new carb gasket kits to my joy and so this effort was essentially FREE plus my time.

Parts replaced:
17mm bolt O-Ring
Main bowl gasket
Needle/seat. I also polished the seat with a Q-Tip on the end of a drill with brass polish during the cleaning (Something I find works WONDERS to leaky needle/seats)
Re-set the float height
Two new drain lines from the bottom of the bowl as those were cracked bad. (The top ones were OK but I did cut them back 1/2" to get some new rubber on the carb vent nipples)
I noticed the bowl screws were kind of long - like 1/4" too long. One of them was long enough to cover access to the Idle/Air screw - so I cut that one screw back for better/future access.
1 new gasket/o-ring at the top of the throttle slide cover

Cleaning action:
Piano wire through jets
Bucket of carb 'dip' for 20 minutes
Hot water with dawn dish soap
1 full can of carb cleaner
90psi compressed air back and forth through every passage (Clears everything, dries everything from water and carb cleaner)
1/4 box of Q-Tips (Used about 100)

Jetting, which I did NOT change:
50 Pilot jet
Air screw at 1&5/8 turn
145RD main jet (Whatever RD means)
35A needle at -1 leaner from middle

Pics:

PICS of carb cleaning b4 vs after

PIc

Did you every find out what the red switch on the steering wheel does?

It wasn't connected to anything. Whatever wires were installed, were then cut.

SO, the Engine just failed pressure testing. Pumped up to 4psi, it leaked at the clutch side Engine seal. Not sure about the flywheel side as the covers are still on but since it failed and was visibly blowing soapy bubbles; she's done.


SOOO, I need to rebuild this bitch :) Time to take the whole Engine and tank out of the frame before I go any further.

Could the button be a horn?

If it was raced, might need a horn.

Pretty small for a horn though.

At least you know it will rip even more when you fix the leaks and freshen it up!

From the look of the carb, I would give it a long bath before you pull the Engine. No fun working on dirty machines.

In light of the Engine failing pressure issues, I've pieced together the first round of things required for a rebuild.

Front and rear crank bearings:
1. 93306-30629 $34.71 https://www.partzilla.com/product/yamaha/93306-30629-00
2. NICH 6306.C3 $19.83 https://www.amazon.com/Nachi-Bearing-Ja ... B0045DWBDM
Balance shaft bearing 1&2 $10.13 ($20.26) https://www.partzilla.com/product/honda ... 8915eb0a40
Top end bearing Wiseco B1023
1.5mm piston Wiseco 577M08150
Drain crush washer $0.75 https://www.partzilla.com/product/honda ... 8915eb0a40

So, in my box-o-parts from the previous owner, I actually have a mostly complete gasket kit, which includes case, cylinder, O-Rings and a bunch of other gaskets which seems to have me covered.
From an Engine seal perspective - I know the double lip seal is tough to find; but again I was given a complete seal kit from the PO, and so I already have a 42x65x10 (Single spring but whatever - inside the cover) and a 30x45x8

Looks like its going to cost me $300 +/- for parts, and then my Engine guy should be able to bore the cylinder for me. I will ask him about cylinder modification :) This is presuming the crank is in good shape and the bottom end bearing can continue service.

that's the truth man. I pulled the seat out to pull the exhaust and pressure test, and so that's all staying out. My cleaning method consists of pressure washing, scrubbing, and UTV cleaning solution which I spray on with my left hand while scrubbing with my right. The pressure washer is for caked on mud.

I need to pull the Engine and break her down before I finalize any ordering.

Ripped the Engine out and started taring her down. Crank looks good which I am happy about because I don't have a good way to replace the bottom end bearing unfortunately - unless someone has any ideas. I'm just one large 1-5/8" nut away from splitting the cases at this point and so I've placed total orders for everything I need. Came to $320 total but again I had a lot of things already, and I added a new intake 16221-430-000 to that list.

Watching this thread. Thanks for all the info. When I saw that carburetor my first thought was "Where did all the oil on it come from?"

Actually, I did end up finding the carb drain o-ring sitting on top of the rear belly pan. It was actually complete.

And so, I've decided to ask speedchaser about rebuilding my crank - it would be a shame to not at least find out and try to do this now.

Also I took the head off/apart again, and I can say this head is NOT a speed chaser head. The cooling passage design is different, and so this is likely a K-Fab head. The dome is a 47cc domes which means high octane only and no pump gas. I'm fine with that.

Also I found ring gap to be HUGE at 78 and 140 thousandths! Standard is supposed to be 18~24 thousandths with a 28 max! The rings were badly worn out and the really loose one almost twisted past the ring pin - so, I SAVED the day rebuilding this thing now.

The cylinder is measuring 80.9mm and so a bore to 81.5 should be good.

The piston was also badly worn. Clearance was so loose I'd say 24 thousandths. Its supposed to be about 5 thousandths!


LOTS and lots of parts added to the order to fix this pilot:
Front crank bearing 91033-HE0-005 $34.71
Rear crank bearing 91032-HE0-005 $19.83
Front oil seal 91203-HE0-003 On hand
Rear oilseal 91204-HE0-003 On hand
Gasket kits On Hand
Case/Crank seals - On Hand
New intake 16210-HE0-000 $63.54

Balance shaft front bearing 91002-HE0-003 $17.63
Top end bearing Wiseco B1023 $15.00
1.5mm piston Wiseco 577M08150 $118.30
Crank O-Ring 91304-MG7-003
Drain crush washer 94109-12000 $0.75
O-Ring for cover 91301-PH8-005 On-hand
Exhaust Joint Pipe 18291-HE0-000 On-hand
Water pump seal 19217-PA5-003 $39.99
Water pump nut and washer $2.05
1-5/8" Crowfoot $13.83
22x2.4 O-Ring for cylinder dome $9.00
Crank O-Ring 91304-MG7-003 $9.16
Fuel reserve gasket 37811-MB1-008 $6.95
Tank O-Ring 23x2.4 91304-GC8-003 $4.95
Petcock Orings 16077-HA7-671 On hand
Right case cover seal 91201-402-015 $14.49
Water pump oil seal 91201-965-000 $6.50
Water pump bearing 91001-KA4-003 $16.75

Noticed this Engine was missing all dowl pins
Case dowl pins PIN, DOWEL (10X28) 90701-399-000 (From a different Honda) $3.86
Case/cover dowl pins PIN, DOWEL (10X16) 94301-10160 $2.90
Cylinder dowl pins PIN, DOWEL (12X20) 94301-12200 $2.90

Polaris Fuel Pump 3085275 - New from PartZilla/Polaris $64.35
Thermo Fan Switch https://www.americanvolt.com/collection ... ure-switch $21.15
16mm x1.5 to 1/8NPT for fan switch https://www.amazon.com/GlowShift-Female ... B00NWZZBS6 $11.98
Exhaust manifold metal 'ring' 18358-HA2-010 $15.88


And then some:
Tank re-surface - $85 from a local radiator shop
Rod kit: CR500 ProX - $85 (Sale price)
Crank service: Competative Crankshafts - $170
Belly pan - $245 shipped from California
Cylinder bore to 81.5: $50

Approximate total: $1,180.85

Some of the prices above include shipping as I had to make several smaller orders from different places going.

I'll likely edit this specific post from here on out to keep record of everything ordered and done in one place.

Speed chaser did offer 2 dome sizes

viewtopic.php?f=4&t=15353

Speedchaser is awesome, but right now he's a bit too busy with work to offer help in re-building my crank. Also I don't think his head domes will fit this K-Fab head.

So I do have another option for rebuilding my crank - that is, send it over to Jeff Seabold at Competitive Cranks. He's a great guy, and helps sell, and rebuild ADR cranks in my jetski world, but also does many other 2-strokes. He only charges $75 to do the work, and has only asked that I include the rod kit to rebuild. So I've gone ahead and ordered the ProX CR500 rod rebuild kit.

You can find Kfab over at minibuggy.net. PM him for info on the head. Nevermind, i was late to the punch.

So the crank in this thing looks to have been serviced before. The front stator side bearing was a HotRods bearing, and the rear/output was actually a Koyo. HotRods bearing seemed ok, but the koyo bearing was on it's way out - turning blue. This is where the crank seal was leaking hence the rebuild. Both bearings are getting replaced with the best available parts I can find. Honda/Koyo front, and NICH 6306.c3 rear. I'm not building a wheelbarrow here.

Also looks like the last crank<s> may have lost some parts somewhere along the way - as I see some light scoring of the inside cases. Almost like a bottom end bearing went out previously, or the Engine injected something small. I found no metal shavings and so that failure must have been way long ago. Great news is, the cases are usable - and in fact I almost missed seeing the scoring all-together. The cylinder may have been re-sleeved at some point but I cannot honestly tell. The cylinder has a marking, 33274.. Can anybody tell from this picture?