GT750 cylinder withou intake divider?

[Vintageman]

Did some GT750 cylinder come factory without intake divider?

http://www.ebay.com/itm/Suzuki-GT-750-W ... 98&vxp=mtr" onclick="window.open(this.href);return false;

[oldjapanesebikes]

Not stock ones that I'm aware of - any I've seen were after market mods.

[Vintageman]

I asked person for pic closeup. we'll see if he sends.

Anyone ever push this divider back?

On my 1975 the rubber boot dia versus the cast start of inlet is very mismatched in Dia. The casting is smaller than rubber boot. Even considering the casting inlet was chamfered a bit to try and match there is still maybe 2mm flat edge all the way around.

[Barry S.]

I ground my intakes smooth to the I.D. of the rubber, got to help it some.

[Coyote]

Intake divider? OK I'm lost. Intake divider?

[oldjapanesebikes]

Intake divider Chris.



I'm in the process actually of removing most of the divider in my play engine, and matching the intake rubber ID to the throat ID.

[Vintageman]

Based on my inquiry the eBay person added closeup of intake.

If not factory it looks well done. Look atthe oil pipes (inject or SRIS?)

Well I must have triggered someone here today,maybe, for there are now bids on this one.

Let us know if you think this was modified or a unique a factory (even if after posting ends ).

I will match my boot/intake as well and maybe push back thin divider a bit

[oldjapanesebikes]

Based on my inquiry the eBay person added closeup of intake.

Those added photos help a lot. That's a stock K block, from between frame 31252 and I think perhaps 40838 or so. I don't see the recesses for the emblems on the block side, so if that's correct it isn't an L, hence the guess at the 40838 number as an upper limit. It has the spigot carburettor mounts introduced at 21134, and also the revised SRIS inlet on the left intake introduced at 31252 which is where my guess at the lower limit comes from.

It still has the divider - but it has the different porting that Richard (TZ) likes. The porting/intake was changed to what you see in the photo I posted introduced with the M in the 1975 model year.

[tz375]

Early 72 barrels had bolt on carb flanges and that short bridge

Later 72 and 73 barrels kept the short bridge and changed to spigots for the carbs.

Late 72 had the same early type SRIS with two SRIS lines to one transfer port

73 (K) were the same short divider but had later style SRIS with two at the front and one at the rear under the left intake port.

74 introduced WATER COOLED badge with the same port timing and a longer divider

85 (M) on had the same long port divider and different port timing.

So that set of barrels are from a 73 K

Maybe I can send pictures of them all to Ian to include in his next update of the Field Guide.

[Vintageman]

Thanks,

never knew this.

Why did Suz add the full intake divider ?

They did this on the T500 as well as we know. On the t500 they widened the twin port windows as well when they added the divider casting.

Are the port window widths ( I know height changed in 75) all the same size for GT750 72-77?

I see one possible reason for the rumor that the 72 GT was "claimed" to have a little more power than 73 or 74.... maybe

1) Bolt flange shorter length then spigots. 2) No full intake divider.

Just a guess. I can't see how the intake divider helps performance??

Thanks again

[Coyote]

Duh

[Alan H]

The port divider stops the piston rings expanding into the port so you can have a wider port without having the piston rings breaking.
Remember that the rings are pegged so they can't rotate (as a 4 stroke rings can) and the ring ends finish up in a port with catastrophic results for ring, piston and bore.

[aslsmm]

i have a late model 73 block if any one wants it. pm me an offer. i need to remove it from the bottom end but its for sale. cheap too.

[oldjapanesebikes]

1) Bolt flange shorter length then spigots. 2) No full intake divider.

J, K and L also had the cross couplers as well as different external and internal design of the exhausts (the hole in first baffle plate of the centre pair of silencers for example was changed with the M from 29 to 20 mm), as well as the jetting on the carburettors, 5th gear ratio and sprockets - so lots of changes. I don't know that you can point to one by itself as making a difference - its a package.

Maybe I can send pictures of them all to Ian to include in his next update of the Field Guide.

That would be great - thanks !

[Vintageman]

The port divider stops the piston rings expanding into the port so you can have a wider port without having the piston rings breaking.
Remember that the rings are pegged so they can't rotate (as a 4 stroke rings can) and the ring ends finish up in a port with catastrophic results for ring, piston and bore.

No, not the casting divider, the fact the aluminum casting extends the divider all the way back to inlet. Why is that added, what good if any is it.

1) Bolt flange shorter length then spigots. 2) No full intake divider.

J, K and L also had the cross couplers as well as different external and internal design of the exhausts (the hole in first baffle plate of the centre pair of silencers for example was changed with the M from 29 to 20 mm), as well as the jetting on the carburettors, 5th gear ratio and sprockets - so lots of changes. I don't know that you can point to one by itself as making a difference - its a package.

Maybe I can send pictures of them all to Ian to include in his next update of the Field Guide.

That would be great - thanks !

Yes many changes, but you exclude I said one of the possible reason. This is really funny for same points can be said about T500. Several changes but many believe intake length key. I doubt it at the rpms were talking that matters at all. I kept asking and we found intake timing was different. same with Later GT250, that exhaust added more baffles, but other changes well made up for it (sure add chambers too). The T250 had shorter carb slide allowing full throttle versus the 73 gt250 which are longer and partly block full throttle. So far I/we have good luck finding which seams to matter a lot IMO. In my experience there is usually one or two changes that dominates more than others if you can't have all or want to keep basically model year original.

I do think the full Aluminum divider is restrictive. Again I have never heard any reasoning for it and just look at other designs for example.

If someone knows do tell.

I am thinning and trimming some of it and matching to intake boot.