2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: Striker1423 on June 25, 2022, 10:51:19 AM

Title: GT750 Starter Clutch
Post by: Striker1423 on June 25, 2022, 10:51:19 AM
Hey fellas,

Here's a quick video I made showing the starter clutch play I've found without completely disassembling the clutch. I don't know what's normal or not for these, so I figured I'd ask here. The suzi2t forums I pisted about getting the cases welded up and its been crickets. They don't seem to be as active on that site. 

Here's it running.
https://youtu.be/JUchEtf3bvU

and here's it not running and taken apart.
https://youtu.be/UjXAATrgpbY
Title: Re: GT750 Starter Clutch
Post by: teazer on June 25, 2022, 11:47:07 AM
Pull that and tighten those 3 screws immediately.  There should be zero play between the gear and the clutch hub.  That will eventually cause major issues and also effects ignition timing.

The screws should be staked/punched to stop them from coming loose. I had a similar issue about a year ago, so I used Red loctitie and then punched the thread ends to prevent a repeat.

https://pinkpossum.com/GT750/Crank%20pullers.htm  for into on suitable pullers.
Title: Re: GT750 Starter Clutch
Post by: teazer on June 25, 2022, 11:47:21 AM
If you need parts, let me know.
Title: Re: GT750 Starter Clutch
Post by: Striker1423 on June 25, 2022, 12:00:13 PM
Ok, they are staked, so I'll see if they'll tighten more  and then give them a good smack with a sharp punch. Harbor Freight it is for a puller set.
Title: Re: GT750 Starter Clutch
Post by: teazer on June 25, 2022, 06:31:42 PM
Either way, you have to remove the clutch assembly, so you might as well clean it out and check the springs and rollers and when you reassemble it. get those screws really tight and make sure they stay tight.
Title: Re: GT750 Starter Clutch
Post by: Striker1423 on June 28, 2022, 01:29:57 PM
Fixed!  Went to Menards and got three of the same size tapered bolts but with hex heads instead. I used red Loctite on them and also impacted the shit out of 'em, so they're not coming out. After fighting with the clutch rollers, it's back in place. The keyway was absolutely fine too. So, just need the new gasket and a few extra quarts of Belray Gearsaver.

Also, I am getting a Carb Sync Pro in the mail, so I can try to get it idling better. Aside from the broken side cover, cracked case, the dire need for chain and sprockets, as well as tires and inner fork tubes, it seems like its ready to ride. :haw:
Title: Re: GT750 Starter Clutch
Post by: teazer on June 30, 2022, 11:25:38 AM
That's good you fixed it.

Crankcase damage is a PIA to fix and very common.  I have had a couple of sets of cases welded up then I ground them back and they look as good as new. 

Broken side cover?  which one?  Motor cover or frame cover. Both can be welded - obviously with different materials and tools.

Carb synch on big two strokes is always a PIA because the pulses are so large which makes it hard to get a comparable steady reading. Next GT I think I might tap the inlet stubs for vacuum take off and see if that works any better than shoving a tool into the carb inlet.

O ring 530 chain rubs the sprocket seal housing unfortunately, so you might need to go with a 520 or X ring. You could use an RD350 front sprocket (same splines) or use an RD400 or TZ350 sprocket on a GS transmission.   Just sayin'.

BTW, I highly recommend Accent ignitions and fitting a relay in the ignition circuit and extra fuses don't hurt but are a lot more work to rewire for them. And the relay in the ignition circuit also helps with the alternator regulation too.
Title: Re: GT750 Starter Clutch
Post by: Striker1423 on June 30, 2022, 12:17:12 PM
Teazer, I still have my old RD front sprocket. I'll count the teeth. If its close enough, then I'll run it for sure. Back sprocket is bad too, but not as bad. Yea Accent ignitions sound awesome, one step at a time here.  I ordered a side cover gasket, was a set of two for 10 bucks. They sent me three. All OEM. So, that's a win. The points carrier can come off a few times now.

The side cover for the chain. The one that goes to the engine case is broken same area where the case itself is.

This popped up today too. https://www.facebook.com/marketplace/item/530898172161455

Dangit lol
Title: Re: GT750 Starter Clutch
Post by: teazer on June 30, 2022, 12:46:53 PM
Those are supposedly barn finds?  I have seen fully restored bikes that don't look that good.  BTW the "74" is actually a 76 I think. It's not a 74 with that tank and forks, but who's counting?

I will check my stash of parts and see if I have a good spare.  They do tend to get broken though.
Title: Re: GT750 Starter Clutch
Post by: Striker1423 on June 30, 2022, 02:18:11 PM
Quote from: teazer on June 30, 2022, 12:46:53 PM
Those are supposedly barn finds?  I have seen fully restored bikes that don't look that good.  BTW the "74" is actually a 76 I think. It's not a 74 with that tank and forks, but who's counting?

I will check my stash of parts and see if I have a good spare.  They do tend to get broken though.

I was wondering. Thought the 76 was the flip up tank lid. It lloks immacualte. If I could knock him down to 4k for that one. I might just get this one back together and sell it.
Title: Re: GT750 Starter Clutch
Post by: teazer on June 30, 2022, 02:51:20 PM
Correct.  76 and 77 had the larger 'square" tank with the cap cover.  72-75 had the earlier tank shape which is nicer looking to my eyes at least.  Early 72 looked the same but had many small differences including a steel radiator cap cover compared to plastic on 73-75. 

The late Ian Sandy had all those details on his oldjapanesebikes site IIRC.

How much are the two "barn finds" just out of interest? 
Title: Re: GT750 Starter Clutch
Post by: Striker1423 on June 30, 2022, 03:02:40 PM
He had it up for 10k. Not clue if that was just a number. Haven't asked him.
Title: Re: GT750 Starter Clutch
Post by: teazer on June 30, 2022, 04:06:16 PM
That's a big number in the US.  UK prices tend to be higher though.

I did find a couple of Inner sprocket covers.  One is painted and looks like it was repaired.  You are welcome to that as a replacement or to break off bits to repair yours - for the cost of shipping.

there is another one here that is worth more than those 189 buck ones on ebay.  No fancy, deceptive polish.  It has a nice layer of genuine, period correct grease and rodent dropping which makes it way more valuable. Don't bother trying to lowball me. i know what I got here. :whistle: :umm: :eek:
Title: Re: GT750 Starter Clutch
Post by: Striker1423 on June 30, 2022, 04:40:12 PM
Ha! I'll take you up on that. I have a few 2x4's and half a sheet of plywood. :haw:
I'll send you a PM.

The price was just a number I think for both bikes. He said make an offer.

Title: Re: GT750 Starter Clutch
Post by: Striker1423 on June 30, 2022, 07:00:44 PM
Back together and sounds great. Except now it won't run lol.
Title: Re: GT750 Starter Clutch
Post by: teazer on July 01, 2022, 10:04:25 PM
Pull the plugs and turn it over with a wrench and check that the "PROPELLER" is roughly in the right place as each cylinder approaches TDC.  It that's off, the drive peg might have fallen out - which would be really unusual, but something ain't right so you might as well start there.

Then spin it over and see if you have all three sparks. If not check that you didn't accidentally hit the kill switch or blow the main and only fuse.

Never met one that didn't fire up easily unless something was well out of whack.
Title: Re: GT750 Starter Clutch
Post by: Striker1423 on July 01, 2022, 10:12:32 PM
Left pot has spark. Checked that before giving up and letting the battery charge.

Points cam spins over ok. So maybe the timing is way off? Like it got adjusted off the loose clutch?
Title: Re: GT750 Starter Clutch
Post by: Striker1423 on July 02, 2022, 10:42:25 PM
Figured it out. Messed with the points plate some, tinkered a bit. Realized it was way out of adjustment and even just fiddling with the points caused a few pops and backfires with nothing before.

I put the DAMN CLUTCH together 45 degrees out of phase. lol. So, drained the oil, took it apart, lined up the left point with the cam and corrected my mistake. Good thing Red loctite hates MAP gas lol.
Put it back together and it fired right up.