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TUNING THE 650 KAWASAKI 4-STROKE TWIN It) M 8, 8'. N ..... '" '" .ci By Rod B -reaker N " 11. There are many riders lamenting Kawasaki's decision to cease importing the 650cc 4-stroke twin model. While it was not the big seller, those who purchased them swore by them. One thing you had to live with if you owned one was people always ask ing you. the Kawasaki gas tank on your BSA? Although this is a sore spot with Kawasaki, the style of the machine was in fact copied from the early model BSA twins. Of course the simi larity stopped there because they made many improvements both in the engine and transm ission as well as the frame and suspension. I can foresee the not-too-distant future when th is machine may possibly become a classic; used ones right now are drawing prices above blue book. . As the import ing of this model was stopped before the printing of Kawasaki's newall-models service manual, many owners are hard-pressed to find service information. For those who would like to do a minor tune-up, here is a step-by-step procedure for them . ~ w Z 5.1 Remove th e crankcase p lug located on the left -ha nd si e of t he eng ine jus t below the motor number w ith a l 7 m m w rench . Again, using th e rear wheel to rotate the eng ine slowly . watch for t he mark on th e flywh ee l to ali gn with th e center of the plug hol e as show n. This is five degrees befo re top dead center a nd t he co ntacts sho uld open at thi s point. w .J ~ O 6 .) If th e tim ing is off th e mark , loosen th e two Phillips screws (arrows) th at sec ure the backing plate and rotate th e contact b acking plate unti l timing is correct. Use a con t inuity light or " buz z box" t o d et erm ine th e exact t ime of poin t se parati on . Rotate the engine 360 degre es a nd check th e timi ng for th e opposit e cy lind er. If there is a difference, yo u will have to ad just the backing plat e to spli t th e d iff erence. Th ere is a different lobe on t he ignit ion cam fo r each cylinder. 1. u t the mach ine on the center stand; it is heavy in t e rear. ou will have to block up th e back of the machine so th e rear wheel can be rota ted to t urn th e engine over as needed. Th ere is no sense even trying to adjust the valves withou t remov ing the gas tank. Remove the gas lines and the tank st ead y bolt (arrow). Use a 21mm soc ket to remove the ce nt er fixing nut and ta ke away the tank. . 7.J Adjust the id le air screw as shown here by turn ing it all the way in and backing it out l iS turns. When the e ngine is fired up , a % turn either way will usually be all that is required for an even tick-over. 8,) As the mach ines get o lder, it may become nec essary to re-adjust the float levels. If so, here is the proper procedure a nd se tt ings for both th e 31 mm earb on th e W-l mod els and th e 28mm carbs on the W models . Again, you may find that these settings d iffer from pr evious in formation re leased by Kawa sak i, so here's the lat est word : p2 l~=. 2.) Use a 10m m wrench to rem ove th e eight nuts holding t ne t wo rocker box caps . In t 30.6nnn pos mon an remo ve the caps . If yo u ruin th e gaskets . obtain new o nes. Remo ve both spark plugs and place t he tra nsmissi on in t op gea r to fac ilita te easy rotation of the engine w ith the rea r wheel. • 27.Snnn GAS K ET SU RFA CE + Float levels should be measured between th e upper carburetor body (gasket removed) and the bottom of the float. The float valve spring should not be depressed when measurement is made. ~ J!!!. ''1- -,, .... .~ Using the rea r wheel to rotate the engine, position valves so that the right exhaust valve is full open, then adjust th e left exhaust valve. T hen rotate the engine until the left exhaust valve is full open and adjust the right exhaust valve clearance. What fun l Rep ea t the procedure for setting the intake valves, l.e. , opposite one full op en . Valve clearances (which must be set on a dead-cold engine) will vary according to d iffere nt factory printed material, but the latest rec om mend at ion is .0 02 in . for t he inta ke valves and .004 in. for the exhaust. ... ~. 9,) T o syncronize the carbs on the two-carb mo del, slip back the rubber cov er on th e cable at the top of the carbo With t he th rott le grip held at the full-open pos it ion. p ull on the housing as show n. Th ere sh o uld be no p lay in either cable. If there is. ad just it o u t using th e ad juster at the top of th e carb oT he same syst em can be used on the choke cables with the lever completely in the "off" position. Install new spark plugs (set the gap at .0 20 ln. }, repl ace the tank and th e timing plug and fire th e engine up . After it is good and warm, ad just th e car bs and ride that muth a l ... 4 .) Access t o the contact points is gained b y removing the two Phil lips screws (a rrows ), securing the cover pla te to the rear of the cy lind er. Clea n the contacts well an d adj ust the point gap to .0 16-.0 18 in . Last installment, Rod showed you how to build a shock-holding tool for Kawasakis. Clever us forgot to print a picture of it . Here it is.