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need help with removing gt750 barrels
Posted: Tue Feb 05, 2013 1:03 am
by aussie gt
Need help with removing barrels, made up a barrel puller, starter to remove barrels ok but then left side moved freely and right side pulled locking bolts out of barrels(holding the puller on) and barrels stopped moving from lower casing.
Re: need help with removing gt750 barrels
Posted: Tue Feb 05, 2013 9:44 am
by tz375
It's hard to tell from the photo, but the barrel appears to have lifted more on one side than the other. When that happens it jams on the studs. Loosen the long "pusher" bolts and smack the barrel back down flat again. It must lift evenly. I find that it has to come up a bit and be smacked down, rinse and repeat as many times as it takes.
It can be a long process. I also flood the stud tunnels with wd40 and I want to see which ones it is not seeping out of. Those are still stuck hard and those need some heat to help the process along.
Re: need help with removing gt750 barrels
Posted: Tue Feb 05, 2013 2:22 pm
by aussie gt
Thanks, i will have it a go cheers
Re: need help with removing gt750 barrels
Posted: Tue Feb 05, 2013 8:56 pm
by tz375
No worries. Good luck with it. Just take your time and use lots of WD40.
Re: need help with removing gt750 barrels
Posted: Thu Feb 07, 2013 4:00 am
by aussie gt
Update, left side is freeing but right side not moving. The right side puller bolts are pulling out of barrels. So what to do ???? Maybe weld and re tap holes or fit insert with new thread (is there enough meat around the holes for this)
Re: need help with removing gt750 barrels
Posted: Thu Feb 07, 2013 9:47 am
by tz375
I would Helicoil those holes. It looks as if teh short bolts were only into teh barrel by 6-8mm. I'd try again with slightly longer bolts or remove those nuts under the heads. If that makes them bottom out, grind a few mm off the ends and then clean up the threads.
The next issue is to work out which of the studs is sticking. It's pretty sure to be the corner with the thicker section. Two of the studs have what looks like a dowel around the lower part just above the crankcase to locate the barrels.
That's a good idea but they tend to chemically weld themselves in place. I'd suggest filling all the stud tunnels with WD40 or similar and most will drain down. On the right side the front one is the one with that fat section. Heat it around the base flange at that right front corner until the wd40 starts to smoke or boil and leave it to cool. Repeat that a few times to try to open it up.
Then fit the puller plate and tension it and then heat it again at that corner and then tension it some more on the right side.
Re: need help with removing gt750 barrels
Posted: Thu Feb 07, 2013 11:14 am
by oldjapanesebikes
Just a +1 to TZ's comments - I've had good success heli-coiling the stripped bolt holes and using the puller. You may also want to take a look at Gunnar's list of options - I haven't tried it myself, but the tool he gives the dimensions for might be an option just to ensure the hole is indeed clear down to the step in the stud. That way you would know the WD40 or whatever your choice of lube is (a 50/50 mix of automatic transmission fluid and diesel works well also) is at least down to where the problem most likely is. The link to Gunnar's material is :
http://www.medial.com/suzuki/cyl-removal/" onclick="window.open(this.href);return false;

Re: need help with removing gt750 barrels
Posted: Thu Feb 07, 2013 11:51 pm
by aussie gt
Thanks tz375 & oldjananesebikes, I will try to use the options you gave me. I had a 74 spare parts motor sitting in the corner of the shed so i try to remove the barrels on it and the results are below.
Re: need help with removing gt750 barrels
Posted: Fri Feb 08, 2013 2:13 pm
by oldjapanesebikes
Proof at least that it is possible eh !

The early barrels lacking the rubber seals are almost always a challenge - slow and patient usually (but not always) works.

Re: need help with removing gt750 barrels
Posted: Fri Feb 08, 2013 3:56 pm
by celt_rock
Wow, and I thought
my studs looked corroded! Yeah, that aluminum is soft, when I made my puller plate I set it on top of the
jug and sent an awl down through until it bottomed out, marked it, and then bought bolts that exact length so I could get as much of a grip on those threads as possible. In my experience though, the WD-40, the Break-away, the PBlaster, even the Coke never made it down to where all the corrosion was... just gummed up my threads

Good luck!
Re: need help with removing gt750 barrels
Posted: Fri Feb 08, 2013 10:07 pm
by aussie gt
Thanks celtrock, at the moment i trying to soften the rust with sprays and moving the barrels up 3mm with puller then hitting it down with block of wood and hammer. Next is to find some heat (oxy) and gave that a go, all these great ideas coming from tz375 & oldjap
Re: need help with removing gt750 barrels
Posted: Sat Feb 09, 2013 5:11 pm
by aussie gt
HAD A WIN, Barrels came off. Had no oxy or 5/8 tap so i found some 10mm wood self taping screws in the shed, so i used them to hold the puller plate. Sounds a bit rough but they worked. LESSON LEARNT . use right length bolts to hold puller !!!!!!. be slow & patient !!!!!
Re: need help with removing gt750 barrels
Posted: Sat Feb 09, 2013 5:50 pm
by oldjapanesebikes
Re: need help with removing gt750 barrels
Posted: Sat Feb 09, 2013 11:57 pm
by tz375
Have to love it when a plan comes together. And the credit goes to others who created those solutions and told me about them. I just payed it forward.
Re: need help with removing gt750 barrels
Posted: Sun Feb 10, 2013 12:11 am
by aussie gt
Thanks guys for the help on the barrels. I will be doing a total motor rebuild so i will ask a lot of questions.