rough/Vibrating engine

lgould · 01-16-2011, 06:42 PM

I have a G9-A that has a significant roughness on acceleration the point the steering shaft and seat shake, this happens at 1/4 to 3/4 throttle and smooths out somewhat there after. I have looked through the forums and have checked the following:
Motor mounts - Good condition.
Carburetor - removed and cleaned all jets and airways.
New drive belt and greased clutch and sheave.
Checked valve clearance - .004, good.
new air and fuel filter.
Adjusted tensioner, Slight play fore and aft.
New BR4ES spark plug set to .030
Removed starter belt and engaged , runs smooth.

Just purchased the cart from an estate so no history but i suspect it was not abused.

Something internal, spark delivery timing? Could use some insight.........

Mike Mac · 01-16-2011, 09:13 PM

I'm still novice, but take the primary clutch cover off and look at the counter weights. One or more may be ready to fail. There are 3.

lgould · 01-16-2011, 10:45 PM

I will do that, thanks.

Mike Mac · 01-17-2011, 12:20 AM

It appears you have been reading the site! This is good! Welcome!
Learn and do all the maintenance, and you will have a good running car.

bud light · 01-17-2011, 12:29 AM

Welcome

lgould · 01-17-2011, 08:17 PM

checked the primary, internal parts seem to be good, small amount of play.
I placed a hand on either side of sliding sheave and there is some rocking motion
it does not seem out of line with what i have read. (3mm).

any other advice?

Mike Mac · 01-17-2011, 10:08 PM

Wait for the biggies now!

haus513 · 01-17-2011, 10:26 PM

This may be way off and / or a long shot but have you looked at the steering / suspension components yet to see if that is a problem and it is just steadying out at top end speeds...

???? Does this happen when your driving or have you tried to put it on jack stands to see if it has the same problem stationary.

lgould · 01-18-2011, 12:04 AM

Happens when stationary on stands. Have remove drive belt, same shudder/ vibration.
Thanks.

DOOmsman · 01-18-2011, 10:46 AM

You may have a balance shaft problem, My cart had it removed
when i bought it.
http://www.yamahagolfcar.com/partsan.../default.aspx#

good luck.

01-16-2011, 06:42 PM	#1
lgould Not Yet Wild Join Date: Jan 2011 Posts: 8	rough/Vibrating engine I have a G9-A that has a significant roughness on acceleration the point the steering shaft and seat shake, this happens at 1/4 to 3/4 throttle and smooths out somewhat there after. I have looked through the forums and have checked the following: Motor mounts - Good condition. Carburetor - removed and cleaned all jets and airways. New drive belt and greased clutch and sheave. Checked valve clearance - .004, good. new air and fuel filter. Adjusted tensioner, Slight play fore and aft. New BR4ES spark plug set to .030 Removed starter belt and engaged , runs smooth. Just purchased the cart from an estate so no history but i suspect it was not abused. Something internal, spark delivery timing? Could use some insight.........
lgould Not Yet Wild Join Date: Jan 2011 Posts: 8

01-16-2011, 09:13 PM	#2
Mike Mac G8 Specialist Join Date: Jun 2009 Location: Phoenix Posts: 7,799	Re: rough/Vibrating engine I'm still novice, but take the primary clutch cover off and look at the counter weights. One or more may be ready to fail. There are 3.

01-16-2011, 10:45 PM	#3
lgould Not Yet Wild Join Date: Jan 2011 Posts: 8	Re: rough/Vibrating engine I will do that, thanks.
lgould Not Yet Wild Join Date: Jan 2011 Posts: 8

01-17-2011, 12:20 AM	#4
Mike Mac G8 Specialist Join Date: Jun 2009 Location: Phoenix Posts: 7,799	Re: rough/Vibrating engine It appears you have been reading the site! This is good! Welcome! Learn and do all the maintenance, and you will have a good running car.

01-17-2011, 12:29 AM	#5
bud light Gone Wild Join Date: Oct 2010 Location: Lawrenceburg Ky. Posts: 1,771	Re: rough/Vibrating engine Welcome

Today
BGW	Sponsored Links __________________ This advertising will not be shown in this way to registered members. Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

01-17-2011, 08:17 PM	#6
lgould Not Yet Wild Join Date: Jan 2011 Posts: 8	Re: rough/Vibrating engine checked the primary, internal parts seem to be good, small amount of play. I placed a hand on either side of sliding sheave and there is some rocking motion it does not seem out of line with what i have read. (3mm). any other advice?
lgould Not Yet Wild Join Date: Jan 2011 Posts: 8

01-17-2011, 10:08 PM	#7
Mike Mac G8 Specialist Join Date: Jun 2009 Location: Phoenix Posts: 7,799	Re: rough/Vibrating engine Wait for the biggies now!

01-17-2011, 10:26 PM	#8
haus513 Getting Wild Join Date: Jul 2010 Location: cincinnati ohio Posts: 129	Re: rough/Vibrating engine This may be way off and / or a long shot but have you looked at the steering / suspension components yet to see if that is a problem and it is just steadying out at top end speeds...???? Does this happen when your driving or have you tried to put it on jack stands to see if it has the same problem stationary.

01-18-2011, 12:04 AM	#9
lgould Not Yet Wild Join Date: Jan 2011 Posts: 8	Re: rough/Vibrating engine Happens when stationary on stands. Have remove drive belt, same shudder/ vibration. Thanks.
lgould Not Yet Wild Join Date: Jan 2011 Posts: 8

01-18-2011, 10:46 AM	#10
DOOmsman Gone Wild Join Date: Jul 2008 Location: Reddick IL Posts: 11,220	Re: rough/Vibrating engine You may have a balance shaft problem, My cart had it removed when i bought it. http://www.yamahagolfcar.com/partsan.../default.aspx# good luck.

Similar Threads
Thread	Forum
g2a running really rough	Gas Yamaha
EZ GO ST350 2004 (MCI engine) running rough and smoking	Gas EZGO
Yamaha G9 engine adjustment ( backfiring issue & running rough )	Gas Yamaha
G16 running rough	Gas Yamaha
G16 Rough Ride	Gas Yamaha