Power Problems

Posts: 6 · Newbie Joined: 28 Apr 2008 Posts: 6 Pictures: 0

My buggy has no power. I can't make it up a small incline (truck ramps, or into the garage), it feels like it is running really rich. The engine will not get up to full RPM's. It spits and sputters when it is at its max RPM that it will reach. The exhaust smells really gassy. Here is what I have done so far:

-Rebuilt the carb (3 times, using carb cleaner and compressed air) (the air/fuel mixture jet has no effect on how it runs. Factory setting is 2 3/8 turns out from stop. It makes no difference to the performance if I run at 0 or 4 turns out)
-changed the plug (the old and new are both really black, rich condition?)
-bypassed the air filter (to ensure it wasn't plugged)
-changed the bystarter assembly fuse

Tonight I am checking the engine compression, changing the vacuum lines, in-line fuel filter and reseat and clean the vacuum fuel assembly attached directly to the fuel tank (which has a small leak) (Thanks Pud for the idea)

I really think this thing is running rich, per the symptoms, but am open to anything reasonable. How do I know if the bystarter assembly is bad? How many ohms should I see if I tested it? Someone mentioned a dropped baffle in the exhaust pipe (but exhaust still comes out), how do I check this? (It won't run without any back pressure, tried it. Thanks for any advice. Ryan

Posts: 3302

Ryan,
Download the Crossfire service manual from here:
http://www.buggynews.com/topic8802.html
(I hope you're not on dial-up!!)

There's a section in it on how to test the bystarter valve by connecting it to power and measure how far it lengthens over some period of time.

It does sound like you are way rich but even with the choke on I think you should be able to tell a difference when adjusting the mixture screw. Did your buggy (and which is it, BTW?) ever run right?

Posts: 6 · Newbie Joined: 28 Apr 2008 Posts: 6 Pictures: 0

Thanks for the link, I will review it tonight. I have a Carter DLX 150 2R buggy. It ran great 2 years ago, it was one of 3 that were bought and it was the fastest of the 3 (by a hair). It then sat at my brother-in-laws as he didn't have time for it. He offered to let me use it for the summer, but it wouldn't start. I changed the fuse to the bystarter assembly (after a carb rebuild) and it started up. I'm guessing that something is dumping too much fuel into the carb and it isn't allowing the air/fuel mixture to make any difference.

Posts: 3016

another way to check it is to remove the choke housing and put a piece of gasket material over it and reinstall it. if it runs better then its the choke

Posts: 6 · Newbie Joined: 28 Apr 2008 Posts: 6 Pictures: 0

BIGE, When you say choke housing, is the area I circled in red what you are talking about (see picture below)? Cover up the 3 holes? I have a CV carb, not sure if this is different than others.

I changed the fuel filter and vacuum lines a couple of minutes ago. No change. It will idle fine, but is very boggy, no power. I will do a compression test this weekend to rule that out, but am still not convinced that it has anything to within the motor itself. Any other suggestions?

Posts: 701

Tonight I am checking the engine compression, changing the vacuum lines, in-line fuel filter and reseat and clean the vacuum fuel assembly attached directly to the fuel tank (which has a small leak)

I really think this thing is running rich, per the symptoms, but am open to anything reasonable. How do I know if the bystarter assembly is bad? How many ohms should I see if I tested it? Someone mentioned a dropped baffle in the exhaust pipe (but exhaust still comes out), how do I check this? (It won't run without any back pressure, tried it. Thanks for any advice. Ryan[/quote]

husk893 i didn't realize your buggy had set that long when checking things also make sure the the vacuum petcock is not bad letting gas come out the vacuum end of it.
maybe setting around that long the diaphragms in it went bad letting some gas by it now. that will cause it to run really rich to, gas also going down the vacuum line.i know guy and bige probably have your problem nailed down for you but it never hurts to look being it has set that long.
also just a thought if you haven't, might want adjust valves first before doing a compression test. that away you will get a good reading.

Posts: 6 · Newbie Joined: 28 Apr 2008 Posts: 6 Pictures: 0

As mentioned earlier I changed the air lines and the fuel filter today, nothing. Tonight I ran the buggy and then looked at the vacuum line from the fuel petcock (as Pud mentioned), no fuel in the vacuum line. I clamped off the vacuum feed from the intake manifold just in case, no difference. I will have to review the service manual link from guy48065 to check the bystarter assembly. BIGE, is the picture I provided where I want to cover up with gasket material? Would a clutching issue cause symptoms like this? What can I look for and where if it has something to do with the drivetrain? Thanks for the help guys, I really appreciate it! If I get a chance I might figure out a way to attached my camcorder and post a youtube video showing how it is acting. Thanks again, Ryan

Posts: 3016

In the drawing where you have the arrow is where the gasket material goes. I have seen clutch pads come apart and cause a jerkig