G1 runs but no speed or power

[Soupy96]

Hello All

I am new to this so please excuse me if there is a related thread. I tried to find info but couldn't narrow it down.

I recently started rebuilding an older G1, not sure of the year.

We can get the engine running but the cart does not go very fast and the engine does not rev up. I removed the carb and cleaned it out and it went good for a minute but after I let off the throttle and took it down off the jacks NO POWER.

There is good spark and the exhaust get hot.
Just wondering if anyone knows where I should look next.

Thanks

[slonomo]

Well, there really isn't an easy answer to your issues if you are not familiar with these carts or with 2 stroke engines. I'll give you the shortest answer I can then you can ask questions....

1. Engine Compression

2. Fuel Pressure

3. Carburator

4. Ignition

5. Primary Clutch

6. Secondary Clutch

7. Drive Belt

These are the major contributors to poor performance. I would start at the top and check all of these areas. You'll find alot of threads here dealing with each one. Also check the "Stickies" at the top of the Yamaha thread section. The stickies are common problems that have been solved.

[slonomo]

If the cart seems to run fine up on jacks (should remove drive belt so axle doesn't turn for safety) and it doesn't have power on the ground, it might be more related to the drive system.

Check the drive belt for wear. It should measure 1 3/16" wide new and no less than 1" worn.

Also check to see that the clutches "shift out" when up on jacks. Be very carefull! Drive clutch should start with the belt low and shift so that the belt rises to the top. The driven clutch (rear) should start high and shift all the way down into the pulley.

If the clutches are good, meaning they shift out properly, then it may be a compression issue. Low compression will likely make it hard to start and it when it does run it will have low power.

[Soupy96]

Okay

Belt does not ride down into secondary clutch.
It only did once. We thought it was an engine issue as it doesnt seem to get to full rpm but maybe i need to look at the clutch assembly.


Thanks

[Soupy96]

Originally Posted by slonomo

Well, there really isn't an easy answer to your issues if you are not familiar with these carts or with 2 stroke engines. I'll give you the shortest answer I can then you can ask questions....

1. Engine Compression

2. Fuel Pressure Good

3. Carburatorremoved and cleaned seems okay

4. Ignitionappears fine

5. Primary Clutch

6. Secondary Clutchbelt does not go down

7. Drive Beltgood

These are the major contributors to poor performance. I would start at the top and check all of these areas. You'll find alot of threads here dealing with each one. Also check the "Stickies" at the top of the Yamaha thread section. The stickies are common problems that have been solved.

Thanks For your help.
I have a long way to go but the cart itself is a good runner and was operational when put in storage couple years back.
I hope to bring it back to life and have some bonding with my father in law, he's the engine man, so I want to be able to help him trouble shoot.

[sho305]

Stick something up the exhaust outlet and make sure it is clear, I had one like that and pulled the muffler loose from the cylinder and then it ran better. Turned out the tailpipe was plugged up inside.

[Soupy96]

Originally Posted by sho305

Stick something up the exhaust outlet and make sure it is clear, I had one like that and pulled the muffler loose from the cylinder and then it ran better. Turned out the tailpipe was plugged up inside.

Funny you should say that. After scouring the post in the wee hours of the am I found a post about a BBQ and thought I would like to try that. I pulled off the exhaust and tried the cart and it runs great. Pretty lucky for having sat in a field for a couple years.
Also thanks to this site I was able to determine that it is a 1982. JT17-00942

Compression is at 90.

Looks like I will get away with just doing some minor body work and paint.
Worst part of the cart is the seat bottoms may have to scrap and start new.
If I figure how to post pics I'll put some up

[Soupy96]

Now on to the easy parts. Tomorrow I fix the brakes.

[sho305]

I just did some brakes had new shoes, turns out the arms that run the shoes were not moving well. I cleaned and worked them until they moved easy then the brakes worked great....and I still have some new shoes lol. I sanded the shoes and drums a little though, they grab nice now.

Some BBQ the muffler, some you can run them hard and they will burn out and smoke a lot until its burned. Oil collects in them if used for short trips was a problem when they were new. That one I stuck a big screwdriver up it and around to clear it, then it was fine. He sold that cart for 600 or so I thought too much it needed steering work and seats were bad, front shocks not good, etc., and it didn't have much power (or I would have bought it).

[slonomo]

Well it sounds like it still could be an engine performance issue. If it's not getting enough rpm the secondary clutch won't engage as it should, almost like it's stuck in first gear.

If you bbq the muffler, make sure you really clean it out good afterwards. Those particles left in there can kill your engine. Blow it out with compressed air, or rinse it out with water a few times and leave it out in the sun to drain/dry.

Yeah the brakes can be a pain on these carts. Although they are very simple, the rust over the years can be your worst enemy. Like Sho said, take it all apart, clean and lube everything that moves, and make sure everything moves before you put back together.

Sounds like you're doing just fine with it. Good luck!