Cycle News - Archive Issues - 1970's

1.0 CN ... Q) ,.0 o .<-J U o Works Performance Shocks on a Pipes Works swingarm and it S&W fork kit provide 8.5 inches of travel front and rear, quite an improvement over stock MR-175 suspension, CB.izin"g the Honda MR·X7S This is the MR·175 that Honda could be building ; By Larry Langley Jerry Counts is a self-confessed lightweight enduro class freak. On top of that he is a Honda enthusiast. With the ever-increasing 16 popularity of the 175 class , . the competition is getting pretty tough, especially since the introduction of Yamaha's brilliant IT-175 . Jerry rode his modified XL-175 to the number 2 enduro lightweight plate last yea r , and even bought a C&J frame to try and keep the four- stroke competitive. However, it soon carne to light that . on ly a good performing two-stroke could do the job, and that led to another question: What to ride? Jerry wanted to stick to a Honda, but wasn't too awfully enthused about sinking a lot of money into a MR-175 which was saddled with inadequate suspension and a frame which bends like cold licorice. When Jerry saw the bike that Honda built for Rick Munyon to campaign in the ISOT Qualifiers, he knew that was the way to go. Basically: Honda had crossed a CR-125 with a MR-175 , using -the best components of each to construct the fin ished product. Now , not every person who wants to \ build a copy has the money. or resources to build such a machine, but by picking up a CR·125 (used) at a reasonable price, the bike can be built to a tight budget. It helps if you know someone at a Honda shop, maybe talk them into a semi-sponsorship (p arts at cost plus 10% ). The bike can, and has been duplicated by others, and has proven itself competitive. To start with, Jerry found a CR-125 at a very reasonable price. .The engine, tank, ' fenders , and swingarm were set aside to be sold to help defray the cost of the project. CR-125 engines have a good resa le value. A new MR -175 engine ('77 version) was purchased. An alternative would be to find a used MR ·175 , but since the '77 engine was desired for .its close ratio transmission , Jerry sprung for a new engine , because a used '77 MR would be priced almost as high. The engine top end was disassembled and the cylinder was sent to Mettco for Fred Hayes to p ort. Fr ed , a member of th e Montesa Endu ro Team , has b een doing development work on MR ·17 5's since th ey first carn e out with the green tankers in 1975 . The fac tory MR -175 . ridden byJay Tullis has always had th e Mettco porting. Fred can port it mi ld . medium or the "j ay Tullis Specia l" which is full race . Jerry chose the in betw een job. The engine was th en mounted in the CR fra me with the MR coil and wiring, and th e bik e was trucked to 'Bassa ni's for a pipe to be put on . Bassani also has been developing pipes for the MR 's but th e MR /CR hybrid required a custom up pipe. Bassani built one for Jerry and it turned out very ni ce. The air bo x required a slice out of th e upper left comer for the pipe to clear. Also the petcock on the MR ·175 gas tank had to be moved to the righ t side of the Bassani up pipe provides needed extra power and tucks iri extremely well. tank for pipe clearance. A couple of. fins had to be trimmed from th e head for th e up pipe also . A plast ic tank might ha ve so lve d th e petc ock problem , but J erry wanted the bik e to "look" Honda . . Back from Bassani's , the fr ame had a rear frame loop weld ed on to su pport a Preston Petty IT fender and a Malcolm Sm ith tool bag . The rea r mot or mounts (a CR weakness) were also re welded . A Pipe Works swingarm was mounted with Works Performance shocks attached to give about 8 !02 " of rea r wheel travel , plenty for end uro use . An S&W fork kit went into the stock fork s, supplying 8 !02 " of front whe el travel and improving t he damping greatly. A 34mm Mikuni was slipped on in place of the stoc k Kehin . A 230 ma in . jet, #40 p ilot and #3 slide is a ball park figure for starters on jetting. A K&N air filt er replaced th e stock foam in t he air bo x. . IA bove leftl Full floating rear bra k e was fabri cated and prove d t he cu re for rear w heel hop. IAbove rig ht! Ne w Malcolm Sm ith fold ing brake lever w as welded on, a must to prevent the lever from being tweaked on roc ks or logs. IBelowl The " Bio nic Turke y "ICB Handlel in actio n at the Cal St ate 100 National - the bike performed well. Up front, a Petty "Mudder" fender was mounted , which gives excellent protection from the environment. To ada pt a speedometer to the CR fron f wheel, a 1977 MR -175 . backing plate slipped right on. The '77 unit must b used beca use "the ea rlier backing plates were a little different and will not work. A 1976 XL-175 speedomet er is used because the gear mech anism allows very positive locking when the odomet er reset is used . . Aluminum Inter-Am handlebars ar e used bec aus e they a re virtu ally unbreakable. Sinc e th e bars do not have a cross -ba r to mount instruments , Jerry made his own; mounting for a clock and roll cha rt. Petty H ex grips a ;e use d'. '.'U n b re a ka b le" Irnpac le vers a ~e mounted at both ends of th e bars. To pro tect the e ng ine Jerry fabricated a skid plate from sheet metal. The stock 428 chain was deemed inadequate, so 520 chain was used by bolting on a Circle Industries aluminum rea r sprocke t (48 teeth) and a Honda 13 -tooth countershaft sprocket .u p front (XL·175 or C . 250) . Stock Honda chain is used . For tires , Jerry chose Metzelers front and rear. A 3.00 x 21 up front and a 4.00 x 18 at the rear. Golden Spectro oil mixed according to the can has been used with excellentresults. A folding Hi Po int shift lever was welded onto the stock sh ift lever for better survival in the enduro rock fields . This is highly recomrnendedz even with the gene rous ground" clearance the bike ends up with . -; The stock MR -175 stator powers a MR·175 headlight and the Petty taillight along with, a brake light. A modified MT-125 stator is used when more power is needed, such as a recent night enduro . Jerry bolts on a 100Watt quartz rock scorcher which lights up things considerably. The finished MR/CR is a .very competitive enduro machine. While Jerry was sorting out h is bike , another MR /CR belonging to Ron Wells took the 175 class in the 500 Mile Greenhorn National. Jay Tullis built himself one after bending his stock MR -175 frame in the Greenhorn , and .is very pleased. Jerry says the bike handles extremely well a nd power is good . The onl y thing lacking is a six-speed transmission , which is highly des irable in a 175. Got to keep her screaming for ultima te performance , you know. Sinc e th e bike was built using mostly Honda parts, it seems logical to ask wh y isn't Honda building th is bike inste ad of the mild- mannered ou tdated MR -175 ? Somebody in Japan knows , but they aren't tell ing. •

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