73 engine into 74 buffalo

h2thief · Post by **h2thief** » Mon Mar 22, 2010 8:01 pm

Guys, I am way out of my league here and am going to have a million questions.... please bear with me.... and all opinions will be equally considered...

First, where do I find a gasket kit including head and cylinder block?

Second, what do I need to change to run the 73 engine... I know the oil pump is different... suggestions are appreciated.

Third, since I don't want this to happen again, (lean cylinder) should I look at anything besides the carbs....

Thanks in advance.... Mike

Post by **Suzsmokeyallan** » Mon Mar 22, 2010 8:12 pm

The actual oil pump is not different, its the cable setup/arm linkage thats different on the 74-77 models.
Full gasket sets show up on ebay, expect to pay around $70.00-$90.00 for one from Athena.
Are you retaining the 74 CV carbs??? or going to the 72-73 slide ones?? either way you should make sure the intake tract rubber boots you use are soft with no cracks and not hard and dried out. This is a potential intake air leak issue you dont need for sure, so check them carefully and get new ones if you are in doubt, plus the clamps designed for them as well.

h2thief · Post by **h2thief** » Tue Mar 23, 2010 10:03 pm

e-bay here I come... I found a bunch of parts I want but not much of what I needed.... and I need to build a cylinder puller.... I guess this is going to take a while.... gives me time for cleaning and polishing I guess.... would rather be riding it though...

Post by **oldjapanesebikes** » Tue Mar 23, 2010 10:43 pm

I just ordered a set of gaskets from an outfit in Japan - they sell on eBay under this listing number "130376084301" - might be worth a look. They are not Athena, but then I wasn't completely happy with those either last time

Coyote · Post by **Coyote** » Wed Mar 24, 2010 7:28 am

https://www.partsnmore.com/cat_index.ph ... ory=engine

h2thief · Post by **h2thief** » Wed Mar 24, 2010 9:47 pm

thanks guys, I got a chance to work on the bike yesterday and found a broken starter bolt.... guess I get to learn how to install a time sert soon.... tomorrows the first payday since october so will be buying some parts... yay!!!

Post by **Suzsmokeyallan** » Fri Mar 26, 2010 7:52 am

Good for you, its always great when you can go and buy shiny new stuff...Dont always discount your local dealer though, if you have a good relationship with someone there who likes older bikes you will be surprised how many items are still available..

h2thief · Post by **h2thief** » Sun Mar 28, 2010 11:07 am

Suzsmokeyallan wrote:Good for you, its always great when you can go and buy shiny new stuff...Dont always discount your local dealer though, if you have a good relationship with someone there who likes older bikes you will be surprised how many items are still available..

I am currently working on a wish list of parts with part numbers to take down to the local dealer... although the last couple times I've been there they have been less than helpful... would rather sell me a new bike.... but I will keep trying to turn them to the dark side....

tz375 · Post by **tz375** » Sun Mar 28, 2010 8:31 pm

FYI,

There are three different designs of oil pump, but they all work in the same way and are interchangeable.

http://www.pinkpossum.com/GT750/Oilpump.htm

Post by **Suzsmokeyallan** » Tue Mar 30, 2010 11:44 am

Thanks for your pump internal pics Richard, looks to be following the same issues as the other parts over the years with subtle design differences.
The little gasket under the cover isnt available separately so you just cant strip down a few good pumps to see inside them as this would mean making a new gasket for each one.
To add to that, even the cover over the pump went through some alterations too. Early ones had the breather tube in the case and the covers breather joint located differently.

bighole · Post by **bighole** » Wed Mar 31, 2010 10:39 am

Sheesh, wish you were closer. I have a 74 motor in my 73 buffalo, we could swap!
No holes in the pistons or anything!

-John

h2thief · Post by **h2thief** » Wed Mar 31, 2010 8:00 pm

bighole wrote:Sheesh, wish you were closer. I have a 74 motor in my 73 buffalo, we could swap!
No holes in the pistons or anything!

-John

I would go for it in a minute...

h2thief · Post by **h2thief** » Wed Mar 31, 2010 8:06 pm

ok, question on the counter shaft..... I have checked three of my bikes and there is about a tooth and a half of freeplay.... Since it is on bikes that I know and I don't have transmission problems I wonder if this is normal... or do I get to split the case....

h2thief · Post by **h2thief** » Sun Apr 18, 2010 10:50 pm

Got the Cylinder block off the 74 engine today.... thanks kris..... left cylinder had eaten the roller bearing on the wrist pin so a tear down is in the future... decided to put the 73 engine in and take a chance I can get it running... plan to re-ring and hone cylinders and new gaskets at this point....

h2thief · Post by **h2thief** » Sun May 16, 2010 7:08 pm

Well guys, I got the engine swap done and everything is running relatively smoothly except for some carb issues....I think anyway... I have got a lag in the throttle coming off a stop... I have to rev it and slip the clutch to get it going... I have cleaned the carbs, cleaned and repacked the exhaust baffles, regapped both plugs and points and still have the problem... it runs fine once I get moving.... I did not have this problem before and I am using the same carbs... any ideas????