Overhaul Blog, 1968 750 GT

[Paul Marx]

Exhaust gaskets not sealing at all, sucking oil down the guides.

The top engine bolts don't line up. DPO has elongated the holes in the frame. OMG.

Frame may well not be precise, I wouldn't be surprised. I always put engine in the frame top mounts first and sometimes, the rear needs a bit of leverage.

Paul

 

[Exmoor beast]

Heaps too much feeplay side to side in the tappets, so multiple head issues. The "restorer" back in the US seems to have had a dislike of washers, nuts and bolts assembled everywhere have bitten into and damaged the alloy. The rear brake arm worries me deeply.

How much side float, have you measured it ? I’m doing my ‘69 GT simultaneously, side float is pretty constant .20mm ( if you remember I’m trying to trace that odd 4000rpm rattle we spoke about..)
I’ve seen elongated frame mounts due to lose bolts, any way very interested in the rebuild!

 

[MarnixSFC]

The top engine bolts don't line up. DPO has elongated the holes in the frame. OMG.

More likely result of riding with loose engine bolts..

Marnix

 

[martymoose]

Now ive looked at it again, i agree with you marnix, i reckon vibration from loose bolts has worn the holes oval. I will measure the side float on the spindles, and let you know.

 

[Vince]

One of the XT500 Yamahas I owned had hugely egg-shaped swingarm mount holes, they must get loose and continue to be flogged to death. Poor old bikes run till they drop. My bodgy fix back then was renewing the bearings and welding nice thick washers to the frame. Better than junking it. It stopped a lot of weaving.

 

[CLEMTOG]

9mm nuts??
what are they on?
CLEM

 

[Paul Marx]

More likely result of riding with loose engine bolts..

Marnix

Yup.
A common occurrence, mostly at the rear.

Paul

 

[Paul Marx]

9mm nuts??
what are they on?
CLEM

Monkeys Clem.

Paul

 

[Eurocycleguy]

I am glad this bike will get the TLC it needs.

 

[Air screw loose]

Looks like you have a mix of rockers with one late type SF3 item closest to camera

 

[Paul Marx]

Heaps too much feeplay side to side in the tappets, so multiple head issues. The "restorer" back in the US seems to have had a dislike of washers, nuts and bolts assembled everywhere have bitten into and damaged the alloy. The rear brake arm worries me deeply.

If in need, I may have one of those brake stays but probably simpler just to weld the hole up.
Paul

 

[martymoose]

Head off. Cam chain fitted without the centre plate in the joining link. Rh ex tappet is later type. Side clearances as follows.

Ex. 0.52mm. 0.38mm
In. 0.23mm. 0.50mm

 

[Vince]

Head off. Cam chain fitted without the centre plate in the joining link. Rh ex tappet is later type. Side clearances as follows.

Ex. 0.52mm. 0.38mm
In. 0.23mm. 0.50mm

Cam chain rev limiter, we will all want a link like that.