Affordable GT750 Bearings and Seals (Ebay)

[JSJamboree]

Dave is right. That crank must be 99% junk. Try to find a cheap one on ebay.

Is it a 72-3 crank with big end thrust washers or a 74-77 crank with thrusts at the small ends?

Its a 75 crank, it looked pretty good visually, one of the ball bearings had blown apart but everything else seemed to be ok. I dont remember what all they said was wrong, but I know two of the ball bearings were bad, one of the rods were bad, a couple of the needle bearings were bad and of course all the seals were shot.

I have a 72 and a 74 motor sitting in my garage but I cant get the jugs off to save my life, to get the cranks out. The 72 is just siezed to the studs (there is another thread on here where i tried everything to get it off). The second (74) has 3 stuck pistons, and with the puller plate I was ripping threads out of the head hoping it would eventually break the pistons free.

The only one I see on ebay right now is a 73 and its $200, kinda pricy not knowing what condition its in either.

[tz375]

I had a 72/3 crank rebuilt recently and sent two to get one good one. In my case, the ends of the "good" crank were toast but the center parts and rods were OK. A couple of bearings were bad and one oil slinger. Fortunately I have had a couple of cranks stripped earlier and have a few spare parts for when I need a crank to be built and I'll need a couple of later cranks to be rebuilt later this year.

I have pulled 2 early style cranks out of late style motors and found one old crank with a new style rod - and that doesn't work either. Not many parts in an old style crank can be used in a later crank. Even the wheels are different thickness, rods are different too, but pins and bearings I think are the same.

Keep your eyes open for a suitable crank. - Or strip that 74 motor. If it's just the pistons stuck in the bores there are a few options including drilling out parts of the pistons to collapse them. heat and all those chemical concoctions can also be tried, but to get a crank out, drilling pistons gets it out of there one way or the other. It's not pretty or refined, but needs must.

[Vintageman]

It took me two years to find two OEM T500 rods, and I just had them put in this year.

That is wondeful some are now available

I think Pete O said his T500 bearing oil hole was not in right place, but that may be an easy fix to drill another one.

I wish crusin_image would take the feedback have have the little things fixed like GT750 piston rod spacing too wide, T500 bearing oil hole in wrong place, Carb bowl gasket too hard and won't seal, GT380 piston pin a little loose. ...etc

My last wishes for Santa are
GT550 rods please they are not available, Thank for the GT550 OS piston
Some cast T350 pistons please 0.5 - 2.0 mm. (in OS steps of 0.25mm better so long live the cyclinders)

Someone else in UK gave us oil line check valves


Pete Ot thank you too. a little late fo rme (this time) but, If you motivated him to make these rods you are a hero!

[JSJamboree]

I had a 72/3 crank rebuilt recently and sent two to get one good one. In my case, the ends of the "good" crank were toast but the center parts and rods were OK. A couple of bearings were bad and one oil slinger. Fortunately I have had a couple of cranks stripped earlier and have a few spare parts for when I need a crank to be built and I'll need a couple of later cranks to be rebuilt later this year.

I have pulled 2 early style cranks out of late style motors and found one old crank with a new style rod - and that doesn't work either. Not many parts in an old style crank can be used in a later crank. Even the wheels are different thickness, rods are different too, but pins and bearings I think are the same.

Keep your eyes open for a suitable crank. - Or strip that 74 motor. If it's just the pistons stuck in the bores there are a few options including drilling out parts of the pistons to collapse them. heat and all those chemical concoctions can also be tried, but to get a crank out, drilling pistons gets it out of there one way or the other. It's not pretty or refined, but needs must.

I just got my 72 apart, I had planned to send in that crank, but it sounds like you are saying that the 72 crank isn't going to give me anything of use for my 75 crank. :-/

I know the pistons are stuck, not sure what i'll have to do the rest of the way to get it apart once I get the pistons out. Guess I need to start drilling. I wish the crank was far enough down I could just take a SawZaw to the jug and cut it into three pieces to make it easier to get apart. I worry I would go down to far and cut into the crank which is about the only think I care about.

[tz375]

72 crank wheels are thicker than later cranks, rods are different and so are the thrust washers. If you rebuild the 72 crank, you need to get 72/3 style pistons or find a way to reduce their side play at the small end pin with later pistons.

What parts do you need for the later crank that you don't have?

[JSJamboree]

72 crank wheels are thicker than later cranks, rods are different and so are the thrust washers. If you rebuild the 72 crank, you need to get 72/3 style pistons or find a way to reduce their side play at the small end pin with later pistons.

What parts do you need for the later crank that you don't have?

2 ball bearings
1 seal set
1 rod
1 pin
3 lower pin bearings

[tz375]

Ball bearings are not hard.
Seals are available for many sources
Con Rod - not so easy
Big end pin - not so easy
Big end bearings not so easy.

If Paul Miller has sets of bearings and rods and pins, would he sell you one pin and one rod and a set of 3 big end bearings and if so would that be any cheaper than Cruizinimage?

It may be cheaper to keep looking for a good second hand crank. I have a 72/3 crank that was supposedly rebuilt and has one new style rod. I have no idea how good or how bad the rest of the crank is until it's opened up. Assuming that the "new" rod is OK and the pin is OK and all 3 big end bearings are OK. The "new" seals are all junk but there should be a couple of OK bearings in there, but it's a crap shoot.

If you want to go that way, PM me and we can work something out.

[JSJamboree]

If you want to go that way, PM me and we can work something out.

Sent you a PM,

Im assuming that since your 72 crank has a 74+ rod on it that the lower pin bearings are the same. After getting this 72 apart finally I see the difference in the Rods but it seems to only effect the upper pin bearings and rod weight (this is also what the guy from BillBune had told me).

[tz375]

Correct. The Big end pin is the same. The rods are different in a few ways though. For example later rods are slotted at the small end to improve lubrication. That change was a result of adding thrust washers to the small end and they restrict access for oil mist, so Suzuki added slots and holes.

At the big end, early rods had scallops in the sides to allow oil mist to penetrate the bearing or to allow oil to escape after it was pumped through the big end. Later designs do not have that scallop feature because they are open at the sides - no big end thrust washers.

The big end thickness changed from 22mm to 21mm and would be a "loose" fit in an early crank with excessive side clearance. Other than those small changes, early and late rods are almost identical in length, beam thickness etc.

[JSJamboree]

Thought I would post this for fun, I took the bottom end off the 74 motor (the one with the stuck pistons) to see if it was even worth the continued trouble. Here is what I found, think these bearings are still good

[yeadon_m]

Ooops! it'll all buff out
Mike

[ConnerVT]

If you soak those washers in Evapo-Rust, they should be reusable.

(I thought the crankshaft from my T500 looked bad...)

[Suzukidave]

Well .. that explains why the pistons are stuck

[tz375]

That will buff right out.