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Post Info TOPIC: Identify engine by Serial number on case


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Identify engine by Serial number on case
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Hi Everyone,

Tearing into my new to me TTR project - my first one - bought it not running. Is it possible to confirm the engine year from the serial number stamping?

My bike is a 2003 (build date 06/2002, 10th digit '3') - looks like maybe the engine has been apart - the piston is missing and the connecting rod bent. Someone may have swapped the engine at some point.

Engine Serial number: G307E-006821

Would like to confirm engine year before purchasing parts to rebuild.

Any thoughts on how the connecting rod would get bent this way? Perhaps hydro-locked from going for a swim?

Anything else I should look out for during this repair?

 

Thanks for your time.

Chris



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And I was abit worried about my bottom end ha ha lol. ( sorry mate).

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Super Guru

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Wow - never ever seen a TTR conrod bent like that!!  no

The engine must have come to a very sudden halt so it's worth doing a very thorough check as I am sure you are doing!

A hydraulic lock may explain it if the bore isn't damaged. What' are the head and valves like? 

Another first for me is your engine number. I have only ever seen engine numbers prefixed 4GY for the white TTRs and 4PX for the later blue models with the plastic tank - approx. 2000 onwards. Does anyone else have a blue TTR with an engine prefix other than 4PX?

I wouldn't worry about ordering the wrong parts as there has been very little change in the engines since they were introduced in the early 90s up until production ceased about 10 years ago.

I am interested as to what your plans are for the rebuild. Assuming no other damage to the engine and gearbox, are you going to get the crankshaft rebuilt with a new conrod kit or look for a second-hand one in good condition?

Brian



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i would say its been through water was the oil grey milky if so its had water through the inlet & hydraulic possible the previous owner has cleaned out & put fresh oil in it

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Thanks for the quick responses!

- Good to know the engines didn't change much over all the model years so not to worry about parts - thank you

Bought the bike as a project - previous owner got it on a trade and had it for 8 years in his garage with intentions to repair. Some parts were lost before I got it, so will have to source out things like a throttle assy, oil line banjo bolt, rear brake pivot bolt.

- A Crankshaft repair machine shop in a nearby town will replace the con rod for about $250 cdn including parts
- the bore looks ok, some minor surface rust (i hope) no noticeable ring ridge
- head and valves appear ok but will check them furthur
- oil was clean, but as mentioned the previous owner may have put in fresh oil after the incident
- will know more once I get the cases split this week but the Rebuild plans so far are:
connecting rod
crank bearings
piston/rings
hone cyllinder
cam chain while i'm in there
all gaskets

There is excellent info on this site - thanks to everyone who contributed up to this point to help fellow riders like myself! Looking forward to getting out on this bike (never rode a TTR before!)


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Update:
Excellent info on this site and fantastic service from Steve at ww.totallytrs.com. Purchased parts easily and with excellent communication from Steve. Parts arrived from UK to Canada over Christmas in about 2 weeks. Amazing.
As others stated, engine year did not matter for parts. Thank you.
Still waiting for the crank to come back from machine shop, engine/trans bearings replaced using info from this site (tried the bbq method to heat cases and almost all bearings dropped out just with gravity - works great)
I now have ownership in my name as well - not an easy task, but it's common for dirt bikes to pass from owner to owner without registration transfer here - I don't know why.
Cylinder is honed, valves lapped - learning alot from the great folks on this site and enjoying the process.

Thank you to all members and contributors - what a great site!

Couple of pics of my engine build and one of my other bikes just because I love bikes and miss riding.



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Pleased to hear the forum has helped and that you have had good parts support from Steve wink

I have to say that your workbench has got to be the tidiest and best organised that I have seen - marvellous biggrinbiggrin



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I admire. Very neat job. And a nice white bike.

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Grandpa Tom

 



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Update: Got the rebuilt crank back on Friday, the engine is all back together and now runs! Using a solenoid jumper button for cars, I cranked it over for 10 seconds or so for a few times with the ignition off to build up oil pressure before starting. Used the oil pressure check bolt to ensure oil was flowing. Started up easily, idles fine and revs without bogging when I 'blip' the throttle. (carb was rebuilt too)


What do the pros on this site do for engine break in after a rebuild? For my YZ 250 rebuild, I did a few heat cycles and rode it easy the first couple of times. I will do the same to the TTR unless there are other recommendations.

How soon should I change the oil after the rebuild? Won't be riding for a bit, there's still a couple feet of snow on the ground and it's -14C here at the moment.
Great to hear it finally run - Thanks to the great members on this site!



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All back together and it was nice enough today to take it out for my first ride on a TTR! (just down the street and back) It ran well, idled and shifted fine. Took it very easy, just wanted to try it out.

I also installed new Shinko Tires: MX216 on the front and the 525 Cheater on the rear. The cheater is super soft and gummy - can't wait to hit the trails.

What should the oil in the sight glass look like when it's running? Mine looks like there is no oil in it when running, can sort of see some oil off in the corner of the sight glass whirling around. More when I rev it up a bit. Is this normal? I've never had a bike with an oil sight glass before.

After running then shut off for a few minutes, the oil is about 3/4 of the way up the glass at the full mark. Am I being paranoid about the oil in the sight glass when it's running?


Thanks,

Chris



-- Edited by twoscoops on Thursday 11th of March 2021 12:46:38 AM

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Looking good on those tyres! Congratulations on the rebuild.
Oil disappears from the sight glass when running - that's perfectly normal. It's being pumped and splashed round the cases. As long as the level is right when the engine's off it's all good.

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Bike looks sweet and nice to see the totallyttrs stickers smile

Simon has spot on advice as usual smile



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Thanks!
As always, fantastic and prompt advice here!



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