Hobbyist Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I recently bought a bayou 300 and a bayou 250 For $200 the 250 runs fine however the 300 will not the first thing I did when I got home is I cleaned the carb then I pulled it nothing so i proceeded to check for spark and compression both were they're so I proceed to put a little gas in the cylinder I pulled it nothing the I checked timing it was fine so I bump started it down the road a couple of time it didn't do anything does anyone know What's going on here
 

·
Registered
Joined
·
3 Posts
Discussion Starter #3
I cranked the motor over with the starter and put the spark plug on the block the spark plug was sparking and I have a compression tester that you screw into the sparm plug hole and then you krank it over it made 130 psi of compression and then there is a mark The fly wheel that line up with a mark on the pull start cover when the two line line up it shows that it is at top dead center on the timing gear there is a line that lines up with the valve cover everything lined up so I assumed it had proper timing
 

·
Registered
Joined
·
1,433 Posts
I am not familiar with the Bayou engines at all. However, you having more than one gives you one for comparison. If these have a backup or primary pull-start feature, they probably have a deko (compression release). Some bikes used to have a cable-operated deko tied into a start lever with elec. start. In any case, 130 is great if it has a deko, not so great if it doesn't.

Good question: does the spark plug come out wet? Reasons for that: too much fuel being delivered; insufficient spark or at wrong time; insufficient compression; or restricted exhaust.

To properly test the spark, you need to impose a better load than a open-air spark plug. Take an old plug and cut the ground electrode off it. You need a gap of about 0.150" to impose enough load to simulate a plug under compression.
A open-air plug requires much less juice, and isn't a valid test. Something like a Stens 750-018, or an Oppama PET4000.

Off-hand it does sound like it should run. My basic test for say, generators that have sat for years is to spray brake-clean or the like into the carb. and crank it. If the plug is coming out wet, try turning the fuel off and clearing the cylinder by cranking with the plug out and the plug wire grounded. Put plug back in and give it a spray prime.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #5
I put the spark plug into the motor and grabbed another spark plug and plugged it in and then I cranked the motor with a load and it still had spark I proceeded to plug the new spark plug in and it was popping and trying to start but would not run even with a break clean and starting fluid I advanced the timing to the right of the timing mark by 1,2 links over and the to the left by 1,2 links when It did pop it would be weaker but more frequent and when I advanced it to the left It would just backfire out the carb but it still wouldn't run I've checked the timing key it was fine so in summary, it would pop and try to run but would not run no matter what I would do any tips on what to do next
 

·
Registered
Joined
·
1,433 Posts
Sounds like a valve issue (compression), or plugged exhaust. The reason I suggested you turn the fuel off for testing as if there is enough water in the fuel it'll prevent it from running on even on spray prime, usually fouls the plug.
 
1 - 6 of 6 Posts
Top