Engine Assembly – Clutch

Started assembling the clutch, fitted the oil pump gear and new idler gear and circlips. Fitted the clutch basket and hub then started checking all the plates, which were all within normal tolerances, the metal plates had some blueing, so I gave them a gentle blast to clean up the surfaces followed by a throughout clean.

I took the clutch plates out as a pack and on inspecting them found there were two friction plates next to one another without a metal plate in between, so the clutch must have slipped all the time. Also the bearing in the outer plate was shot so wating for a new one of those to arrive.

Engine Assembly – Engine Mounts

I didn’t like the look of the engine mounting brackets, so blasted them all off then purchased stainless bolts, including my most expensive stainless bolt ever.

Fitting the engine is a nightmare as its such a tight fit, I used pipe insultaion to protect the frame paint, its also very difficult to get the engine into the rear cradle, so I removed the swinging arm and once the engine was in the frame attached the cradle then the swinging arm.

Make sure you fit the bottom cradle bolt first otherwise you won’t get it in and it fits from the left side, only, once the foot peg is removed.

Engine Mount Bolt Sizes

Front mount2 – M8 x 70mm, 1 – M10 x 100mm
Bottom mount1 – M10 x 235mm (I could only find a 250mm so cut it down)
Top mount2 – M8 x 60mm
Rear cradleTop – M10 x 150mm, bottom – M10 x 140mm

Engine Assembly – Primary Gear Nut

I put the engine in the frame to provide more leverage for doing up the primary nut and then had that light bulb moment, my torque wrench isn’t bi-directional, so only torques right-hand threads.

Quick Amazon purchase and I now have a bi-directional torque wrench, bizarrely the ratchet head pushes through, which means its still only torqueing right-hand threads but as its now reversed its a left-hand thread, who knew!

Engine Assembly – Cylinder Head

I’d previously blasted and painted the cylinder head, so time for valve lapping and new valve seals then assembly plus new stainless studs and dome nuts, so I don’t have all the problems I did when taking the engine apart.

Gallery shows before and after lapping valve.

I set the valves on the bench and bought the Suzuki tool, which makes the job very easy and was dirt cheap, you’ll also need some angled feeler gauges.

Just make sure you have the piston at top dead centre on the compression stroke. To do this rotate the engine anti-clockwise and watch the inlet valves open then continue rotating until the rotor timing mark is aligned which the mark on the crankcase.

Couldn’t find any specs on the o-rings for the valve covers, so bough several and did trial and error until I worked out the right size 65mm ID. I’ve read several times about the covers leaking so went for a 3mm thick o-ring which should sort that problem.

All of the head cover bolts were replaced with stainless ones, I could’nt get stainless flange bolts for the two long bolts, so had to settle for allen socket ones and don’t forget the two sealing washers on the two inner bolts.

One thing to note I’ve photoshop’d an image of the cam to show how the sprocket should be fitted, as I found several posts on forums where people were fitting the cam and then aligning the wrong thing. The tab washer fits over the guide pin and its the guide pin that sits at two o’clock when fitting the cam NOT the hole next to 32E.

The cam must also be fitted with the sprocket off, as there isn’t enough clearance to fit an assembled cam. Just ensure you have the cam white dot at the top and have something covering the cam chain hole, as you can only fit one bolt at a time and have to rotate the engine to fit the second bolt, very easy to drop one into the engine. I replaced both bolts and the tab washer.

Cylinder Head Cover Bolt Sizes – refer to image in gallery

1 M6 x 25mm 7 M6 x 115mm
2 M6 x 25mm 8 M6 x 55mm + sealing washer
3 M6 x 30mm 9 M6 x 55mm + sealing washer
4 M6 x 115mm 10 M6 x 30mm
5 M6 x 55mm 11 M6 x 25mm
6 M6 x 55mm 12 M6 x 25mm

Engine Assembly – At Last!

Finally started the engine rebuild, the clean newly painted crankcases had all the ncessary new bearings fitted (remembering to remove seals where necessary) , gearbox installed, crank installed. I just followed the workshop manual plus all new stainless bolts.

All the gearbox selector springs and small pins were replaced. To deal with the neutral light switch bolt issues, I used some small aluminium spacers and schnorr washers (google it!) plus loctite.

I’d also bought a new cylinder and piston, at this stage I realised the silver paint on the cylinder didn’t match the silver I’d painted the crankcases. I prepped the cylinder and repainted in the contrasting cast iron colour I’m using on other parts. I think I gives the engine some dimension rather than it all being silver, which I’m pretty sure is done only to keep costs down.

I bought a set of stainless engine bolts only to find it didn’t include the ones that hold the crankcases together, so I bought those from eBay. Simple diagram showing sizes in gallery.

You have to temporarily fit the rotor to assist with tightening the nut on the primary gear. Doing that on the bench is very difficult as it requires 100Nm and is left hand thread, enjoy!

Gearbox Rebuild – 3

Final gearbox parts have arrived, so reassembled the gearbox this morning. Pretty straight forward just follow the manual, only things to watch out for is the countershaft 5th gear spacer has an oil hole so I marked it with a sharpie to check alignment on the shaft and the circlips have to be assembled with the sharp edge facing the correct direction, both detailed in the manual.

Fitting 2nd gear back on the shaft required the press again, I gently heated the gear with a hot air gun then tapped it on to ensure it was straight then pressed it the rest of the way using an old socket. The manual says to use loctite, wtf, its so tight loctite would just be pushed out of the way, so didn’t bother with that step.


Moved onto cleaning the carbs. They were in a state and required extensive cleaning plus standard o-ring, gasket replacements plus stainless bolts. Vacuum system had previously been removed so I bought the proper Suzuki blanks to cover the outlets.

I don’t have a ultrasonic cleaner, so I just use degreasant and elbow grease plus a pure brass wire brush. I also managed to get a new choke linkage on eBay at a bargain price.

Have a few stainless screws on order to finish the rebuild.

Gearbox Rebuild – 2

Well went to my friend’s bike shop and we couldn’t get the gear off with a massive puller and considerable heat. So I decided to try and source a new countershaft and rebuild that gearset completely.

Have managed to find parts at good prices. but am not going to let this gear get the best of me and have now managed to get it off.

How you may ask?

6 ton hydraulic press!
whomp there it is!

Gearbox Rebuild

Started rebuilding the gearbox with new 3rd and 5th gearsets. I’m doing those because 3rd is the normal weak point and my gears were outside tolerance and on the original engine 5th let go destroying it, prior to my ownership I should say, 5th was also outside tolerance.

Driveshaft rebuild is pretty straight forward, I’m also replacing all bushes, washers and circlips. The only thing to be aware of is there are two washers that fit together with offset splines, so they act as a basically circlip but thicker to take up slack.

To fit these you must push the circlip on the other side of 3rd gear further down the shaft so that you can locate the two interlocking washers first then slide the gear back and fit the circlip into its groove.

You also need to be aware of this for disassembly, otherwise there’s no way you’ll get it apart. Shown in the first gallery picture, 1 and 2 interlock and 3 needs moving in the direction of the arrow, past its locating groove then brought back.

Countershaft has caused a stopping point at the mo due to 2nd gear being pressed on. My gear puller wasn’t up to the job. So will call in another favour and borrow one.


Engine Bearings

The bearings are a little strange in this engine, as some are dual sealed bearings with one seal removed. Caught me out as I measured the bearings in the cases and then ordered them, only to find on removal there was a seal on the back face of three of them.

You can spot them in the photos as the bearings have an extra shoulder visable where the seal would normally sit. The 3rd bearing with seal on the back is the gearbox output shaft bearing.

and this is what happens if you don’t maintain your engine/oil levels…..

5th gear had let go on the original engine, so I’m replacing both 5th and 3rd (usual gearbox issue) gearsets. They were also under tolerance when measured.

All bearings are being replaced because –

  • A – you should
  • B – check video below