Cycle News - Archive Issues - 1970's

·0 ..'" EI C aj o n Succeeds with Second Hare SraDlbles M e, .... '" Ol i ::< ~ w Z w -' U >U . . -- . - . -- By Rod Breaker CHECKING FOR BAD CRANK SEALS ON TWO-STROKE One o f th e most co m m o n problems with two-stroke engines is failure o f th e cranksea ls, I don't mean to say that this is a dread dis eas e that will strike the minute y o u invest your hard-earned cash in a two-cycle. What I mean is that while the two-cycle engine is relatively trouble-free (less moving parts, less trouble ) , an engine hasn't been manufactured yet th at doesn't have a problem of some sort. The principle behind th e two-cycle en gin e is that th e crankcase must h ave a positive seal so that it will hold a vacuum when the piston goes up (t o draw in th e fresh air -gas ch arge) and also hold pressure when the piston co mes down (to force this mixture up through the transfer ports to be compressed and fired) . As the flywhe el sh afts have to protrude out of the cra nkcases to transmit the power (usually on one sid e for drive and on the other for ignition) the sealing around the shafts has been accomplished by installing double-lip seals on each side of the engine. As the shafts turns, the seals wear. . When these seals get bad, they can give you any number of symptoms, such as loss of power, lumpy carburetion, poor cold-starting and sometimes the engine will keep up the RPM 's although the throttle has been shut off. Of course, some of these problems can be caused by other means as well, such as a manifold or base gasket air leak. Also, a clogged muffler that hasn't been decoked will make the engine run poorly and hard to start. Many of the symptoms of bad seals are similar to other problems so you must find a positive system. If you just go ah ead and replace th e seals, it is exasp era t ing to find you still have th e prob lem. Th e seal that seems to give the most trouble is the one on the magnet o sid e b ec ause it is exposed t o the elements. While the other seal is pretty well protected, one sid e b y th e oil in th e fu el mixture and on the o th er b y th e o il in the clutch. The rider does h ave o n e thin g in his favor o n the clutch-side seal, if it goes bad, it wil l usually show up in th e fo rm of heavy smoke from the exhaust as transmission oil is sucked into the crank and mixed with th e regular fuel mixture. By noting the h eavy smoke for no ap paren t reason and also finding a loss o f clutch o il, he can usually figu re out th at th e clutch sid e (o r drive side) se a l has de teriorated a nd n eeds replacement. As the motorcy cle indust ry h as progressed, sophisticated methods of trouble-shooting have com e abou t. One of the most imporant is the pressure test to determine the condition of th e seals on a two-stroke. This is a s im p le matter and it is fairly quick. First , seal off th e exhaust port and the intake port. Then pressurize the lower end with low pressure and gauge it to detect a drop in pressure. This system works well, but the eq uip men t is a little expensive for the average rider who just uses it occasionally. T here is a way t o check the seals that require no inve st m ent and o nly a little time. If yo u suspec t t he d yno-side seal, strip off th e mag and th e sta t o r so yo u ca n see th e seal. Next remove th e head and cyli nder (wh ich is relatively simple on a two-stroke) and fill th e crankcase with a gas-oil mixture. See if it leaks out ar ound th e seal. If, afte r a reasonable amount o f time , no leak is observed, drain out the mixtu re (a siphon will do it ) , reassemble th e motor, and lo o k else where for y o ur problem. If it leaks, simply repl ace it and you will probably have found your p roblem. If it d oes no t lea k aro und th e d yno seal b u t t h e level of fu el go es down, it is probably leakin g on th e clutch sid e. MANIFOLD AIR LEAKS A lo t o f good home mechanics h ave trouble with carburetion due to air leaks at the ju nc tio n of the carburetor and intake manifold or the manifold and th e engine. An air leak here can deal you fits when you are trying to tune a machine. It is almost impossible to get an even tick-over from the engine. Even when the throttle is backed off, the engine still wants to keep th e rev's up before they slowly drop. While a bad au to ma tic-advan ce unit can produce some of the same symptoms, if an air leak is at all suspected, it s.hou~ be checked out..An air leak that Just IS bothersome at idle can be disasterous at higher speeds where a piston seizure or a holed piston could result. The system that I use for checking for air leaks may be frowned upon by Smokey the Bear, but if a little caution is used, you shouldn't have any trouble. I use one o f the small squirt bottles such as the girls used to put on their setting lo tion when they give themselves a permanen t, or any small bottle w ith a squirt-t ype lid on it. I fill this co ntainer w ith a two-c yc le gas-oil m ix so I can use it o n four- and two-strokes alik e. The nex t step is to get th e engine to id le at a set sp eed. The slower the tick-over , th e b etter, but eve n if you can't b rin g th e idle d o wn, y o u will be able to sp ot th e t ro ub le area. After the engi ne has settled d own to a st ead y idle, squirt a sm all amount of this mi x t ure aro und the j oint of th e carburetor and the intake manifold, so it runs around the en ti re joint. Remember, if yo u really douse it, yo u ar e asking fo r a fire , If th er e is an air leak, t h e en gin e will normally stumble and die. At the leas t, it will change the idle and it will b e apparent to even the untra ined ear. Wh en the id le has settled d own agai n, do the same thing to th e j o in t between the in take manifold and the engine just in case they both h ave leaks. If there "is an y doubt in yo ur mind, check them agai n . If yo u h ave a bolt-on type carb , chances are that the mounting flange has been warped from overtightening the bolts. It will have to be surfaced with a piece of fine sandp aper on a section of plate glass or o ther fla t surface. Also, check any fiber insulatin g blocks for possible cracks that could b e ca using air leaks. Corbett Continues to be Thorn in Sanders' Side By Art Loya SOlITH GATE , CAL., March 2, 1972 season's b est efforts for any rider, The fans came to Trojan Speedway Sanders slipped under Hopkin s co mi ng tonight wondering whether Dan Corbett out of the seco nd comer in th e 250 F.T . could repeat stopping the winning ways Main to lead the final three laps. of Bob Sanders in the TT and flat track Somehow, it alw ays seems to come racing progr-ollIl. The answer was down to Sanders and Corbett , and affirmative and unanimous. tonight was no different. Well , almost. Corbett not only had t o go all-o ut t o T op riding performances b y Hopkins, beat Dale Hopkins (Bu l) fo r the lead, Vern Ma xw ell , and J o e Bro wn but had to per form at h is very best to highlighted the evenin gs' ac tion much t o the delight o f the fans th at we re literally take t h e checkered flag in the 250 TT Main ah ead of Sand ers (Kaw), who sta ndi ng up so as not to m iss any of the wo rked his way fro m fo urt h on th e close-riding thriJls. third lap to take sec ond on the final la p Making his first start of the season, Hopki ns displayed m uch of his win ning ove r Hopkins. In w inning o n his T & R Industries fo rm th at has carried h im to n umero us ch am p ionshi ps, but clearly showe d a Bultaco, Corbett was all a pro rider cou ld be, but so me how Sanders st ill lack o f con trol in hand ling the fifth- mile k e p t so m e 0 f t h at w inn in g o val when he was fo rced to relinquish dcterm inat io n in reserve to top th e lead to b o th Corbett an d Sanders. Still, he made his point b y giving the Corbett 's winning effort by dueling with Hopkins fo r five thrilling lap s tr y ing fa ns no tic e o f his in tentio n to take h is share of Main Event action real soon . every thi ng in th e books to ge t by th e EI (R esu lts on page 36) Monte rider, and finall y with one o f the There was a hole filled with powdery dust th at eliminated some riders and dang near elim inated th e winn er, Ope n Expert Randy Hodg es (2) . By Bob Grant OCOTILLO CAL. Feb. 27 1972 holding second. After two laps the Usually onc~ a ye'; a club wiiI throw a riders switched with Bud Willis (CZ) desert team scrambles. Last year the EI taking ove~ for King and Ran~y Hodges Cajon M.C . held a su cc essful one and (Hu s) takmg over for RenIck: After d ecided to do it again th is year . R id ers about an hour th e team of Renick and Hodges had : taken ov er the lead and like these races for several reasons. One o f w h ich is that maybe you can team up eventually came in f?r the w in .a,:,d first with that gu y th at has b een b eating you Open Expert t eam. Kmg and WillIS hung all year or pressing you hard. They also on fo~ s~ond. At th e end of 2 ~ hours provide a lot of p it ac t io n with th e o f racin g It was pretty hard to tell who tr ading off o f riders and all. was where overall, however th e team of T his race started at 10 a.m, with Chuck Vesco (Y am) and Bruce Shepard a p p r o x i mat el y 100 "first t eam" (yam) were ~h e firs t 250 . ~ xperts and ng~t In there in o verall positron, members taking off from a Le Mans st art. At th e smoke bomb it was Scott [he course was extremely dusty and Kin g [Suz] and Ken Renick (Yam) a lot of riders took some nasty spills. running very close. The co u rse was set B~t generally the ra ce was h an~led well With the memb ers of the El Cajon M.C. up in a 13 mile oval with four ch ecks . It deserving credit for th is unusual and was to be run for 2 ~ hours. First rid er through the pits on th e successful event. (R esu lts o n page 3 6) firs t lap wa s King with Renick still .M.O.R.E. {Cont 'd. f rom page 5) mean ing a co untry which butts up to the county o f residence. There ar e many lo cati ons within a County where a person may reg ister. Almost every fire station participates in the voter registration program. You can determine the nearest place of registration by calling either the County Clerk's Office o r the County Registrar of Voters, if your county has o ne. The t eleph o ne numbers can be found under the County listings in the white p ages of your Telephone Directory. Be sure to look under the name of yo ur county : "Los Angeles, County of" . DEPUTY REGI STRARS Any cit izen ma y become a Deputy Registrar of Voters. It is a sim p le jo b which requires no fin ancial expense and requires only simple training in how to fill out the registration forms. Some co u nt ies even pay a fee for each voter registered. In California, Kern County pays 30t, Los Angeles and Sacramento Counties pay 25¢. but the average is about lOt per voter registered. We hope t o e n c o u r a ge the mo torcycle dealers to have one of their employees become a Deputy Registrar so th at h e might register cus to mers who are not yet registered vo ters. Motorcycl e clubs should e nc o urage one o f their mem b ers t o d o the same and ensure th at all club memb ers are regist ered vo te rs. An d, how about this for a possibili ty: have a Deputy R egistrar availab le at all mo t orcycle races and even ts . With th e fees paid by th e cou nty, a cl ub co uld certainly p ick up a few bucks fo r its treasu ry . ABSENTEE VOTERS Th ere are two types of absentee vo ter: those who will be tempora rily away fro m their resid ence o n Election Day and those wh o are more 0 less permanently away fr om th eir resid en ce, such as military personnel. In either case , the law provid es yo u with the opportunit y to cas t your b allot. Military personnel need only write to the County Clerk of the county in which they ' legally ' reside and all registration material and ballots will be sent to them free of charge. If a non-military person is not registered, and is temporarily away from his legal res idence, he may register by writing to the County Clerk of the co un ty in which he legal ly resides and request the necessary registration forms. If a non-military person is already registered, but willbe away from home on either of the Election Days , he can obtain an Absentee Ballot by contacting the County Clerk of the county in which he legally resides. MOTOR-VOTER CAMPAIGN Well, there y o u have the framework for our Motor-Voter Campaign. We hope to locate the funding necessary to provide every motorcyclist in California who is registered to vote with a bumper -sticker wh ich proclaims "MOTOR-VOTER" and contains a replica o f a mo torcycle. W e f e el t ha t ou r el e c te d re p resen tatives mi ght h ave second th ou ght s a bo u t b ad mo t orcycle legislat ion if t hey knew how many registered voters ther e are in th e motorcycli ng ra nks. \\ollat b ett er way t o let t hem kno w than t o ado rn our bum p er s wit h "MOTOR -VOT ER " sticke rs . Does anyone k now a philanth ropist wh o is also a motorcycl e en th usias t? Address a ll c o m m ents and /o r inquiries to Ru ss Sanford , c/o M.O .R .E., P.O. Box 26062, Sacramento, CA 95826 or lephone (9 I 6) 363·0265.

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