lifted club cars - lifted ezgo
Home FAQDonate Who's Online
Go Back   Buggies Gone Wild Golf Cart Forum > Golf Cart Repair and Troubleshooting > Gas Yamaha
Gas Yamaha Gas Yamaha Golf Cars; G1 through "The Drive" and U-Max Utility Vehicles



Post New Thread  Reply
 
Thread Tools Display Modes
Old 12-04-2022, 05:37 PM   #1
SteveCSC
Not Yet Wild
 
Join Date: Aug 2022
Posts: 51
Default JN3 rebuild or ???

So just pulled cart #2 into the garage for the winter project. it is a G14 (I think) with a JN3 - 301 engine. It smokes, but has decent compression. I was planning to just stock rebuild it, as this is the one I am going to eventually sell to pay for the work on my primary limo cart.

While I haven't popped anything open (yet) to see if it's been bored before, looking for experiences with this rebuild - how far is enough to get a decent build ? (yes I know it matters what measurements come out as, if its been bored and so forth)

Sort of looking for the most basic rebuild list that I can start to price out.

Thanks in advance.

Oh, and the ???? part is - I have a 13hp predator, but am hesitant to get into fabrication. I can do it, I just, really don't want to, although if that might be a better way..............

And yes, it's a splash lube, has already been used/beat on a bit former mud motor predator.
SteveCSC is offline   Reply With Quote
Alt Today
BGW

Golf car forum 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
   
Old 12-04-2022, 05:45 PM   #2
CP241
Nincompoop village idiot
 
CP241's Avatar
Club Car
 
Join Date: Apr 2018
Location: Michigan
Posts: 9,625
Default Re: JN3 rebuild or ???

If you already have the predator engine, vegas carts has everything you need for an easy bolt in solution to mount it in the cart. Probably run you ~$500-600 for cradle, clutch, belt, and misc parts.

As for the rebuild, nobody can tell you what it needs to be rebuilt. The only thing you can do is grab the service manual, tear it down, and replace anything that’s worn. Plus gaskets and seals and stuff.
CP241 is offline   Reply With Quote
Old 12-04-2022, 05:58 PM   #3
augiedoggy
Gone Wild
 
augiedoggy's Avatar
 
Join Date: Apr 2008
Posts: 2,223
Default Re: JN3 rebuild or ???

I have a g2 that has the same engine from g2 to g11 I believe... I have a few rebuild kits in my watch list. here is one for the g14.. they have a version with valves for $120.

https://www.ebay.com/itm/40397610037...id=14052347698



it comes in different bores as well.

Theres actually a full rebuild video on ebay. I cant remember if its a g11 or g14 motor though.

If its got good compression but smoking its likely just the valve seals which are cheap and easy and prone to smoke on these engines.
augiedoggy is offline   Reply With Quote
Old 12-04-2022, 06:27 PM   #4
CP241
Nincompoop village idiot
 
CP241's Avatar
Club Car
 
Join Date: Apr 2018
Location: Michigan
Posts: 9,625
Default Re: JN3 rebuild or ???

Actually there’s only a valve seal on the intake valve. And they seldom are an issue.

These engines generally smoke for one of two reasons… either coked up oil control rings stuck in the piston, or the cylinder is shaped like a bell and gets bigger at the bottom. Neither results in a compression loss but can make it smoke like a train.

99% of the time it’s stuck oil rings


And for what it’s worth, stick with oem parts. These Yamaha engines do not like aftermarket rings, rod bearings, etc. oem is still available. If you use the aftermarket stuff youre lucky if it makes it a year before it starts smoking again.

Cylinder bore is important too. Too rough with the hone grit and it will eat the chrome off the new rings even faster.
CP241 is offline   Reply With Quote
Old 12-04-2022, 07:19 PM   #5
raydhd
VC 460 CLONE GONE WILD
 
raydhd's Avatar
Yamaha
 
Join Date: Oct 2014
Location: Ray BY The Bay NJ
Posts: 10,593
Default Re: JN3 rebuild or ???

I ran my stock G 14 from 2008 to 2014. I bought a smoker for low $'s. The key is don't buy anything until you measure,measure,measure. You don't know where you are until the engine is torn down and you see where the bore is and what it looks like. The only fatal situation is when it is at the max piston size and the cylinder is scored deeply or badly out of round. I agree with use genuine yamaha parts. I was able to get by with being slightly out of stock bore size with new rings and a set of rod bearings. Ran 350 hours and then parted the engine out for $950 and switched to VC 460 power.
raydhd is offline   Reply With Quote
Old 12-05-2022, 12:32 AM   #6
slonomo
Searching for The Way
 
slonomo's Avatar
Yamaha
 
Join Date: Oct 2009
Location: Medina, Ohio (NEOHIO)
Posts: 11,421
Default Re: JN3 rebuild or ???

Quote:
Originally Posted by CP241 View Post
Actually there’s only a valve seal on the intake valve. And they seldom are an issue.

These engines generally smoke for one of two reasons… either coked up oil control rings stuck in the piston, or the cylinder is shaped like a bell and gets bigger at the bottom. Neither results in a compression loss but can make it smoke like a train.

99% of the time it’s stuck oil rings


And for what it’s worth, stick with oem parts. These Yamaha engines do not like aftermarket rings, rod bearings, etc. oem is still available. If you use the aftermarket stuff youre lucky if it makes it a year before it starts smoking again.

Cylinder bore is important too. Too rough with the hone grit and it will eat the chrome off the new rings even faster.
Good advice sir!
slonomo is offline   Reply With Quote
Old 12-05-2022, 07:21 AM   #7
augiedoggy
Gone Wild
 
augiedoggy's Avatar
 
Join Date: Apr 2008
Posts: 2,223
Default Re: JN3 rebuild or ???

heres a video on a JN6rebuild https://www.youtube.com/watch?v=ZeF-pC4jQJk Id spring for an actual cleaner work bench myself if I were attempting this. This is the first ive heard aftermarket amazon/ ebay kits being bad actually but ill admit I only did a quick google search and read reviews on amazon. I have no actual experience with this kit as some here do.
augiedoggy is offline   Reply With Quote
Old 12-06-2022, 06:58 PM   #8
SteveCSC
Not Yet Wild
 
Join Date: Aug 2022
Posts: 51
Default Re: JN3 rebuild or ???

Thanks ! affirmed a lot, it's going to be teardown and get measurements. Bad part for me is finding out if my machinist is still;

a. alive
b. working
c. wants to hit this small engine

While I have the t-handle bore/caliper measuring tools, obviously using the 'right' tool, as well as ability to get good measurements off crank/cam/bearings is better than what I can do.

Will update later in the winter on the project/
SteveCSC is offline   Reply With Quote
Old 12-06-2022, 07:39 PM   #9
raydhd
VC 460 CLONE GONE WILD
 
raydhd's Avatar
Yamaha
 
Join Date: Oct 2014
Location: Ray BY The Bay NJ
Posts: 10,593
Default Re: JN3 rebuild or ???

With some luck you may not need a machinist. Just the right parts
raydhd is offline   Reply With Quote
Old 12-14-2022, 04:59 PM   #10
Daman1340
Not Yet Wild
Yamaha
 
Join Date: Aug 2020
Location: Maryland
Posts: 8
Default Re: JN3 rebuild or ???

Did my G14 a year and a half ago and knew nothing.....was my first cart. (turned out great) i grew up with dirt bikes though so i did have an idea what could come at me. All the Yamaha parts are super available for these and cheap. as said in other posts, make sure u know ur bore size. couple beers and some YouTube time and you're golden!
Daman1340 is offline   Reply With Quote
Reply
Go Back   Buggies Gone Wild Golf Cart Forum > Golf Cart Repair and Troubleshooting > Gas Yamaha


Thread Tools
Display Modes


Similar Threads
Thread Forum
99 CC DS Rebuild - What can I do without? Electric Club Car
G-1 REbuild Gas Yamaha
96 TXT rebuild Electric EZGO
Rebuild Gas EZGO
G16 rebuild Gas Yamaha


All times are GMT -5. The time now is 03:26 AM.


Club Car Electric | EZGO Electric | Lifted Golf Carts | Gas EZGO | Used Golf Carts and Parts

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This Website and forum is the property of Buggiesgonewild.com. No material may be taken or duplicated in part or full without prior written consent of the owners of buggiesgonewild.com. © 2006-2017 Buggiesgonewild.com. All rights reserved.