gt750 cyls.

derek · Post by **derek** » Fri Jul 31, 2009 8:08 am

hi guys. just wondering if there are any tips on getting the cyls. off the case. i have taken all the head bolts off and gotten the head off with relative ease but i can not figure out how to get the jugs off. are there bolts holding it on inside the case? any help would be greatly appreciated.

oh and if you guys are wondering why i want to pull the motor down.

Coyote · Post by **Coyote** » Fri Jul 31, 2009 8:16 am

No there is no other retention. They are nearly impossible to remove easily. You will need to make or borrow a puller. I have lost the link on how to build one. Possibly someone here has the link or will loan you one.

Post by **Suzsmokeyallan** » Fri Jul 31, 2009 1:40 pm

Just remember to remove the one nut on the rear right side of the cylinder as well.
I built two pullers out of 1/2 inch steel plate, one for myself and one for Suzukidave and they work really well.
I also chose to tap the holes with a 1.25 pitch metric thread for better stress reduction on the plate and bolts material so the high torque doesnt damage the threads as easy.
These particular bolts have a concave end so it sits evenly on the convex head of the studs and centres itself.
You can use the cylinder head as a hole location guide pattern for marking out the puller plate as well.
Heres a few photos of how mine turned out after making it. There is no photo of me tapping the threads into the plate but they were done as well.

Post by **oldjapanesebikes** » Fri Jul 31, 2009 3:01 pm

Another version of a puller is shown part way down the page here - its very similar to Allan's.

Note that even with a puller like this, the barrels can still be a real pain to remove, especially the older 1972/1973 ones - you need to soak the stud openings with a good penetrent for a few days - I use either 3 in 1 or PB Blaster.

Suzukidave · Post by **Suzukidave** » Fri Jul 31, 2009 4:05 pm

Here is SmokeyAllan useing his puller on a 72 block

Post by **oldjapanesebikes** » Fri Jul 31, 2009 4:28 pm

Of course, once you get the barrels off you may find that you have other problems

Suzukidave · Post by **Suzukidave** » Fri Jul 31, 2009 4:36 pm

Yuck

Post by **Suzsmokeyallan** » Fri Jul 31, 2009 4:49 pm

Ian it has been proven that penetrant of any sort will never bypass some corrosion on the studs when its locked solid enough.
The 72 cylinder i had and the one i did at Daves both were soaking for DAYS and you can see some of the studs in the photo at Daves shop are still dry.
However water can somehow get inside the clutch as in your photo, that looks very bad...dont tell me thats your recently purchased 73 bikes motor.

Post by **oldjapanesebikes** » Fri Jul 31, 2009 8:31 pm

Suzsmokeyallan wrote:dont tell me thats your recently purchased 73 bikes motor.

Yep - it is the donor engine I plan to use, although I was given this one - possibly needs a bit of oil ....... ?

Seriously, what I plan to do is just replace all the internals including the crank as its in similar shape, and keep the cases and barrels. Should turn out OK - I'll be posting more info on my web site as the project progresses.

About the penetrant Allan - you are correct. For some of the earlier engines especially I suspect you could let them soak for months and not have much luck

- having said that I am starting to be a PB Blaster believer as I have had pretty good luck with it so far.

At any rate - hopefully some of the photos of the two pullers has been of help to Derek who started this thread.

rngdng · Post by **rngdng** » Sun Aug 02, 2009 8:44 pm

On Gunnar's page, he shows how to use a GT750 head as a puller. I have used this method with success.

Lane

Post by **Suzsmokeyallan** » Sun Aug 02, 2009 9:05 pm

I would rather not use the head as a puller on an engine with an unknown value of stuck or severely stuck cylinder, as you could actually distort it.
It could work on an engine you had prepped the studs etc and were removing the parts again after a while, but on one you have no idea about, its best not to.

Post by **oldjapanesebikes** » Sun Aug 02, 2009 11:02 pm

Suzsmokeyallan wrote:It could work on an engine you had prepped the studs etc and were removing the parts again after a while, but on one you have no idea about, its best not to.

Agreed - on a seriously stuck set of barrels, all you'd do is break the alloy cylinder head. A steel plate is a far smarter idea.

tz375 · Post by **tz375** » Sun Aug 02, 2009 11:31 pm

I tried using a head and lengths of allthread like Gunnar's site, but that didn't work for me, so I tapped all the holes and used bolts in teh new threads.

At the same time, I had left it soaking in wd40 and applied lots of heat. The richk is to break it loose and then remove the pullers and smack the barrels back down, and repeat. The lifting and lowering breaks the bond quite effectively, but it all takes time.

I'm sure the ideas came from Suzukidave and they worked - eventually.

On one motor, I had to drill through the barrels to drill out two studs that refused to move.

Post by **Suzsmokeyallan** » Mon Aug 03, 2009 5:10 am

On the barrel Dave had in his shop he had tried all sorts of things to budge it free but it wasnt moving. It was then we had the conversation about me making a puller plate and i offered to make two at the same time to test my design on what was referred to as his "never going to move it" 72 engine.
I had moved my first barrel with a lot of issues so i was a bit knowledgeable about the really stuck SOB syndrome, and figured if my puller broke on his barrel then id have to rethink the plan of attack.
Prior to that i had tried tapping the stud holes in mine for that version of puller but a few were loose due to the castings, so i didnt get much threads and they stripped out on the first pressing.
Its also been known to have the studs push down into the lower case and break off the casting by the transfers so all sorts of things can and will happen on stuck barrels.
I try to move it first off the base then look to see whos a bit stiff and try a little heat on those particular studs if necessary.
The catch phrase here is to BALANCE the torque and lift spacing all across the studs, this will pull the barrel straight and evenly on the studs so hopefully it will come off.
Dont be surprised if it takes nearly an hour to lift it clear off using the slow but proven technique of doing this way on the stubbornly stuck ones.

derek · Post by **derek** » Mon Aug 03, 2009 8:05 am

im going to build a puller tonight and give it a go. its been sitting in pb blaster since last wed now so hopefully that will make things a bit easier for me.