Spark plug gap on 72' chaparral thunderbird? [Archive] - Snowmobile World : Your #1 Snowmobile Forum

: Spark plug gap on 72' chaparral thunderbird?


ballzy1
01-14-2002, 10:17 AM
Anybody know the spark plug gap on a '72 Chaparral Thunderbird 400. I just bought it and wanted to check the gap. Check it out, *it's got a new seat, new track, new belt, rebuilt motor, and new bogie wheels. *Starts on first pull. I only paid $350 for it.

sleddinfool
01-14-2002, 10:34 PM
Ballzy, hate to burst your bubble but that sled looks like a 73. It was probably built in 72. The 72's had a different seat and a different hood, which are the major parts. I believe the plug gap is 18-20 thousandsths. Nice looking sled though, Kevin

sleddinfool
01-14-2002, 10:40 PM
Ballzy, I just looked at my service manual. the spark plug gap is supposed to be .022-.o26 Kevin

mxz5
01-16-2002, 01:33 PM
Do you have the spark plug number? My buddy just bought a 72 firebird 400 with a Fuji motor. It had NGK BH7S's in it. Are they the right ones?

ballzy1
01-16-2002, 02:19 PM
Looks like a '73?! Huh. The guy I bought it off of said it was a '72 . How else could I make sure of the year?
According to the NGK website those are the right plugs - B7HS. I also answered my own question on the gap - .020

sleddinfool
01-16-2002, 11:45 PM
Ballzy, difference between a 72 and a 73. 72's had all bogey wheel suspension, 73's had a slide type suspension but didn't use slides, just a metal rail, kinf of like scorpions para-rail, some people put the 74 suspension on as they had tru slides. The handlebars if they were 72, would be chrome and have no cover and metal throttle and brake levers. The 73's have the plastic "flipper" style levers and a cover over the bars. The 72 and 73 cowl is different, the 72 uses a rounded windshiled the 73 uses a more of a sqaured off windshield at the top. The hoods are slightly different and the 72 had metal louvers on the hood where the 73 had plastic. Kevin

mxz5
01-17-2002, 09:38 AM
Thanks for verifying the spark plugs. I would have to say that's a 73 too. The other guy's differences plus the rear bumper is newer looking. Is yours a Fuji motor? We raced a 72 tnt 340, a 73 scorpion super stinger 400 r/v and the Chapparal 400 and all the Chapparal saw was tail lights. I thought it was gonna be the other way around.

tsouth
01-20-2002, 08:04 AM
I had a 73 chap as a kid and that looks like one
I still have a 74 that needs work (motor parts) i live in s,e mich aneybody know whair to get parts

sleddinfool
01-20-2002, 11:14 AM
What kind of motor parts? What size engine. I think I have a 400 chap motor for parts. I just sold a liquid chap motor. Kevin

tsouth
01-20-2002, 03:41 PM
crank bearings needlecage bearings for a 440Lc

sleddinfool
01-20-2002, 08:23 PM
Sorry, I don't have any liquid stuff, been a few years since I owned a liquid. I had one mint one I sold about 11 years ago, it was perfect with round slide mikuni's and the whole nine yards. I bought it from a guy that used to sell chaps and it was mint. Kevin

stumble-out
01-21-2002, 09:43 PM
I just got a Thunderbird too,was wondering the year?the seat is smooth(sayshapparral on back),different grab bar on back;chrome handles on each side,chrome bars,dash cowl is cut up,but looks different than this one.real small gas tank,under seat says 11-70?thanx

sleddinfool
01-21-2002, 10:17 PM
Stumble, sounds like you have a 71. Is the seat in good shape? Pretty rare to find them good.Does the seat have kinf of like a flying bird on the top? Kevin