Scoop pokes a sharp­ened stick at his long term pro­ject and waits for it to bite him on theº

Classic Motorcycle Mechanics - - COTENTS -

Steve Cooper re- starts this trou­ble­some spe­cial.

If per­chance you were won­der­ing what might be hap­pen­ing with Pro­ject Rickuki then you’re not the only one! ve oc­ca­sion­ally re­dis­cov­ered the rolling chas­sis as ve gone look­ing for stuff around the garage and made a mental note that re­ally need to get back on it again. How­ever, as seem to be blessed with the re­ten­tion span of a sh these days of­ten uickly then for­got about it. The fact is my good mate Dave, who vol­un­teered to make the reed-valve car­ri­ers, has (over the course of sev­eral months) moved work­shop, waited for­ever for a sparky to wire his ma­chines up, and asked some­one else to do some of the ma­chin­ing who then dis­ap­peared on hol­i­day for ages (no, that wasn' t me be­fore you ask!). Spe­cials such as the Rickuki seem to en­tice problems like a feral cats at­tracts eas. The good news now is that ma­chin­ing is done and can be paired up with the af­ter­mar­ket Miku­nis: well al­most. The left carb ts ne but the right oat bowl an­noy­ingly hits the very top of the oil pump. Some­times spe­cials can in­deed be very spe­cial! Hope­fully we have a plan but it' s yet to be ex­e­cuted: once again it' s suck it and see' time. Else­where things are ac­tu­ally look­ing rather pos­i­tive. Rob Pem­ber­ton of SPA Mo­tor­cy­cles, the guy who con­vinced me ac­tu­ally wanted this pro­ject in the rst place, has pulled the mo­tor apart to see if it' s as good as was claimed. When acq uired was told the mo­tor was fully sorted and while had no rea­son to doubt the claim it' s good to be re­as­sured. The crank is sound and al­though the rods have been used be­fore there' s no

dam­age or sig­niae cant wear. t' s a big old lump de­signed to be ro­bust and re­li­able but uite why it needs to weight close on fteen ki­los is any­one' s guess. That said this rel­a­tively large mass prob­a­bly ac­counts for the low revving, lop­ing, easy go­ing na­ture of that uniq ue mo­tor. Even if the bike was rst drawn up in the mid-60s there' s in­ter­nal ev­i­dence of some ad­vanced think­ing here which may very well have come from MZ via Ernst Deg­ner. nside the crankcases are packer ribs de­signed to re­duce the vol­ume be­neath the pis­tons and thereby in­crease pri­mary com­pres­sion thus speed­ing up fuel/air trans­fer to the com­bus­tion cham­ber. While it might not look like a lot of metal in the words of a well-known su­per­mar­ket' s ad­vertº ev­ery lit­tle helps! Thank­fully who­ever built the mo­tor added plenty of oil so the likes of the lit­tle-end eyes are in ro­bust health, ditto the main and big end bear­ings. One job that does need at­ten­tion is re­place­ment of some faux-en­gine studs that are ac­tu­ally DI store stud­ding. Now know why there were some ap­par­ently spare Suzuki studs in that box of spares: note to self, never throw jack away un­til the job is done. Any­one who knows much about Suzuki T500s will tell you they' re po­ten­tially no­to­ri­ous for tak­ing out fourth and fth gears. Even af­ter Suzuki modiae ed the cast­ings to blank off a semi-blind cast­ing that robbed the box of pre­cious lu­bri­cant and added an ex­tra 200ccs of gear oil, high mileage ex­am­ples can make the most ap­palling me­chan­i­cal whin­ing sounds be­fore the top two cogs go AWOL. Thank­fully my gear­box has been pro­nounced tick­ety-boo, so no vast ex­penses or hunt­ing down rare partsº well not just yet any­way. gen­er­ally try not to get too en­meshed (sic) with gear boxes but Rob P reck­ons the T500' s is ac­tu­ally uite an un­usual de­sign. Ap­par­ently the se­lec­tion dogs are not on the backs of the gears as is the case nor­mally. This means all ve gears are con­stantly be­ing driven on the in­put shaft. Now whether or not this is a good or bad thing is to­tally be­yond my ageing brain but ev­i­dently can take some re­as­sur­ance that it' s not an un­heard of set up. Seem­ingly amaha used an ex­tremely sim­i­lar sys­tem on their mile eat­ing, six-speed, JR13 00 so we can all sleep easy know­ing that.

The cylin­der heads will get a check over for at­ness at the gas­ket face and will also be care­fully vol­umed to en­sure we' re okay to run on mod­ern un­leaded. They' ve al­ready been heav­ily re­worked post in­stal­la­tion of the wa­ter jacket. The spark plug holes have been re­lo­cated cen­trally and also up­graded to take long reach plugs that will, in the­ory at least, bet­ter dis­si­pate heat. Know­ing Rob P' s love of two-strokes and his pas­sion for get­ting the best out of each and ev­ery one the bar­rels have had a se­ri­ous talk­ing to. Vast amounts of swarf, some steel but mostly al­loy, give wit­ness to the black art of two-stroke port­ing. The aim is to lib­er­ate some ex­tra ponies yet not make the bike overly peaky. look on se­ri­ously im­pressed as Rob grad­u­ally dis­ap­pears un­der an ever-grow­ing pile of metal de­bris. Ap­par­ently both my in­let and ex­haust ports have now been proae led, matched, har­monised and up­graded. This will aid in­let lling and ex­haust scav­eng­ing along with im­prov­ing gas/air trans­fer from the crankcases to the com­bus­tion cham­berº and all in the name of ow dy­nam­ics. So far, in this episode of Rickuki build­ing ve not spent any money yet! ve told my­self that the straight cut pri­mary gears bought some years ago no longer counts so nan­cially m do­ing well. The idea be­hind us­ing this style of pri­mary drive that es­chews the more con­ven­tional he­li­cal teeth ar­range­ment is that straight gear ab­sorbs less power due to re­duced fric­tion. They may be nois­ier but that' s not re­ally an is­sue now as my hear­ing is shot to hell any­way. How­ever, the old au­di­tory or­gans perk up when Guru Rob men­tions might be in­ter­ested in a close ra­tio gear­box. He reck­ons that to make the most out of the re­worked mo­tor our com­bined in­ter­ests would be best served by opt­ing for a Nova Trans­mis­sion T500 CR Kit Type B. This is not a cheap op­tion but it does take out the chasms be­tween most of the shift changes. Most cru­cially it will al­low the bike to max­imise on both torq ue and power. n case you were in­ter­ested ac­cord­ing to Nova: the B kit com­prises a new in­put shaft with rst and sec­ond gears ma­chined on the shaft and a press on third in­put gear; also sup­plied are rst and sec­ond out­put gears. The Nova out­put gears must be built onto the cus­tomer' s stan­dard out­put shaft with stan­dard Suzuki dog rings. The stan­dard Suzuki in­put gears must be pressed onto the new Nova in­put shaft.º So now you know and yes my wal­let has been sig­niae cantly light­ened. More news as it breaks and as soon as ve got over the shock!

Thanks this month to; Nova Trans­mis­sions 01403 711312

Right-hand reed block and carb.

Bits that make up the reed valve.

Check­ing the se­lec­tion dogs.

Can you see the packer ribs?

Crank set-up.

Lit­tle-end eye.

Check­ing en­gine studs.

The blind cast­ing.

Lower en­gine case/gears sorted.

A Rickuki cylin­der head.

Pri­mary gears.

Port­ing in progress.

Swarf in the hole!

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