Bottom end rebuilt time! (official rebuilt thread)

jentzschman

Well-Known Member
Location
Sandy, Utah
Well, here it is. The official engine rebuilt thread!

To start off: Went for a ride out at the Stansbury mountains today. Got about 20 minutes into the ride at some open road in 5th gear and BAM! I had been struggling to get it to shift during the ride into 4th and 5th... Thought it was the cable so I played with it real fast then kept going. Still had a hard time getting into 4th and 5th but pressed on. Shortly after she died on me. Pulled the plug and she looked great. Had that nice brown color with no signs of white ash/ being lean.

So, with out further delay, this pics:

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Then, the fun part. Found this waiting for me after taking the cylinder off:

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So, she sits in pieces until I can get the whole motor out and start tearing into it.
 
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jentzschman

Well-Known Member
Location
Sandy, Utah
5/26/13

Here is how she sits now:

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Trying to keep thing organized:

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(keeps telling me remote file is too large, sorry)
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Clutch plates and friction discs out:

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Top of piston:

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Ready to have FWW, stock FW, and stator removed:

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5/27/13

Got the motor out: (not to self. Swing arm bolt is 22mm)

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5/27/13

Placed a nice big order from RMATV. List includes:
-Crank assembly
-Main bearings and seals
-The rest of the transmission bearings
-Water pump shaft bearing
-Piston kit
-Complete gasket kit
-Other odds and ends

Whatever I don't end up using, which I doubt is very much, I will be returning. This project is getting pricey so every penny I can save will be nice.
 
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jentzschman

Well-Known Member
Location
Sandy, Utah
5/30/13

First off, huge thanks to Chad for helping me!

Got the flywheel off and stator:

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Then we got the rest of the clutch and basket off:

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With a few other small items off we were ready to begin surgery:

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Tranny removed:

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jentzschman

Well-Known Member
Location
Sandy, Utah
continued from above:

And the moment we all have been waiting for, the crank:

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Parts arrived tonight with the new crank, main bearing, and some other goodies. I forgot to order two bearings, the ones that the shift drum use. So I will be making a run to RMATV tomorrow morning.

Going to get the cases all cleaned up and start getting her back together tomorrow night.
 
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jentzschman

Well-Known Member
Location
Sandy, Utah
5/31/13

Cleaned all mating surfaces and as much of the outside of the cases as I could. Steel wool is a great tool, but man its messy! I have gone through 4 cans of cleaner so as to make sure to get it all. I will be bowing it out with compressed air at Chads before we start putting it all back together:

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jentzschman

Well-Known Member
Location
Sandy, Utah
6/1/13

Again, HUGE thanks to Chad! We had a little hiccup getting the tranny right. Seating the shift drum on the forks, while trying to place the shafts in is a little tricky. However, we got it figured out after a moment. If you take the time out for figuring out the tranny, it only took us about 1 1/2 hours to get it back together, and that was chit chatting every few minutes.

Chads "payment" was to take it for a ride next time we ride. I was more then willing to oblige for all the help he gave me.

Got the crank pressed into one side and fitted the transmission in place:

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Cases are all back together and started getting everything buttoned back up (no pics yet, but I will get them asap)
 
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sixstringsteve

Well-Known Member
Location
UT
bummer. Is the cylinder scored at all? It might be time to have it bored to a 300. :D


Not really, but it is something to consider...
 

UNSTUCK

But stuck more often.
I don't know about all that engine stuff...too few cylinders for me...but I know if I spend any time at all bare foot in my garage, I'd spend the next day picking slivers out of my feet. :D
 
D

Deleted member 12904

Guest
It's not that bad at all to split the cases on these bikes. Take pictures and take your time. The first time I did it I was really worried but it went really smooth.
 

glockman

I hate Jeeps
Location
Pleasant Grove
I have rebuilt several Yamaha bottom ends Trevor. I also have most of the tools (case splitter and flywheel puller) If you need a hand pull the motor and bring it over. I have every Wednesday off.


Sent from my iPhone using Tapatalk
 

jentzschman

Well-Known Member
Location
Sandy, Utah
It's not that bad at all to split the cases on these bikes. Take pictures and take your time. The first time I did it I was really worried but it went really smooth.

Good to hear

I have rebuilt several Yamaha bottom ends Trevor. I also have most of the tools (case splitter and flywheel puller) If you need a hand pull the motor and bring it over. I have every Wednesday off.


Sent from my iPhone using Tapatalk

Awesome! I will get it out and get with. Thank you so much!



Sent from my HTC VLE_U using Tapatalk 2
 

jeeper

Currently without Jeep
Location
So Jo, Ut
The metal shaving look real similar to a bike I bought that fried the main crank bearings. Every thing still felt good as I turned the motor, but then I realized the piston rod had a lot of slop on the crank. Grab your piston and pull it up/down and see if you get play on the crank.
 

jentzschman

Well-Known Member
Location
Sandy, Utah
The metal shaving look real similar to a bike I bought that fried the main crank bearings. Every thing still felt good as I turned the motor, but then I realized the piston rod had a lot of slop on the crank. Grab your piston and pull it up/down and see if you get play on the crank.

Cool. I will go check now....


Ok, it feels very tight/solid. Not sure how else to describe it, but the piston has zero slop in it when pulling it up and down, other then wanting to move the crank...
 
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anderson750

I'm working on it Rose
Location
Price, Utah
The problems shifting make me think transmission. Once you are moving a clutch is pretty much irrelevant to shifting since everything meshes. Also the clutch is going to be separate from your crank in relation to the case. I cannot see the pictures to well on my phone but I am thinking those could possibly be transmission parts.
 

jentzschman

Well-Known Member
Location
Sandy, Utah
The problems shifting make me think transmission. Once you are moving a clutch is pretty much irrelevant to shifting since everything meshes. Also the clutch is going to be separate from your crank in relation to the case. I cannot see the pictures to well on my phone but I am thinking those could possibly be transmission parts.

I am also thinking along similar lines. Not sure why all of a sudden the clutch was being weird today though. It rode like butter up AFC Thursday night :rolleyes:

I pulled the clutch out and it did have a bad smell and the oil was dark. I need to pull the basket and maybe that will unearth something else.... Either way I am going to split the case and find out.

Maybe this is a good time to do the WR tranny swap! :D

So, once I get the motor un-buttoned, I will split it and find out whats up.
 
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