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Author Topic: 363 370 Vibration  (Read 121 times)

Offline havinnoj

363 370 Vibration
« on: November 05, 2018, 11:54:23 PM »
Fellas running 363/ 370cc motors with unbalanced cranks, what's the vibration like?  I can't remember back to the last 350 I had and am considering doing a 363 Sphynx for the spare duner over the winter.  I probably wouldn't care for myself but usually have a gal riding that bike so vibration becomes a bit more of a concern.  Probably won't go that route if I need to spend the extra coin to balance since that motor size is already getting big enough for the spare.
« Last Edit: November 06, 2018, 06:19:21 PM by havinnoj »

Offline broken1

Re: 363 370 Vibration
« Reply #1 on: November 06, 2018, 02:51:37 AM »
I have no experience with vibrations in a big bore but the fact a chick will be riding a 363 sphynx is awesome! My wife gets a measly 250cc oem cylinder.  ;)
overkill is an often underrated achievement

Offline Skeans1

Re: 363 370 Vibration
« Reply #2 on: November 06, 2018, 06:16:01 AM »
From what I remember of my Sphinx the vibrations werenít all that bad nothing like the 431 was.

Online jwraymond6

Re: 363 370 Vibration
« Reply #3 on: November 06, 2018, 07:26:13 AM »
I donít notice much vibration on my 363 sphynx
87 363 sphynx built by Pete @ hybrid engineering

Offline atvcrazy

Re: 363 370 Vibration
« Reply #4 on: November 06, 2018, 09:00:57 AM »
balancing helps very little in my opinion.  Running a standard stroke crank will help the mos with a big bore. Small motors like 72 mm bore or less a 4 mil is fine.  Once you go over that the more they vibrate.  Standard stroke will be easier to start as well

Offline Burns363R

Re: 363 370 Vibration
« Reply #5 on: November 06, 2018, 12:14:01 PM »
I havent had any issues.  I run 2 hour races without problem.  I would say its probably not at smooth as a OEM 250, but then again i cant remember the last time i rode one of those.
TRX 363R 02- Laeger Narrow Frame/CR500 Link, Motowoz Suspension, Roll Design +4 LT Arms,RPM Dominator +4 axle, LED 363 MX, LED 350G Pipe, 38 A/S CR Ignition

TRX 363R 86- Stock frame(gusseted),KOQ-No Link Swinger, JD MGC LT Arms) Motowoz Shocks, LED 370/350D pipe, 38 A/S Carb, CR Ignition

Offline havinnoj

Re: 363 370 Vibration
« Reply #6 on: November 06, 2018, 12:50:41 PM »
Thanks guys, appreciate the feedback.  Probably only one way to know for sure.  It'd be replacing a 300/310PV which could probably use a new piston so I'm weighing whether to put money into that top end or go bigger.