Snowmobile Fanatics banner

1 - 5 of 5 Posts

·
Registered
Joined
·
36 Posts
Discussion Starter #1
hi, i have an old 73 el tigre 440. It has been running great until just recently. It runs fine but after fifteen minutes it starts to bog down and won't go above 5000 rpm's. I notice huge amount of exaust collecting under the hood so i took off the pipe when i got home and i found about a 10 inch crack right by the mounting bracket and all so the connection to the y pipe was all cracked and chipped so exhaust was leaking there to. I think that thins is my problem but i'm not sure. I have heard that you need the pressure from the exhaust pipe to make the sled run right. Is this true, and if not what could it be?
 

·
Registered
Joined
·
68 Posts
It's true. If there is not enough back pressure the sled will bog. It needs it for lower rpms. My sled wont even move without an exhaust. Also if there is no back pressure you can blow your motor. I doubt it would hurt yours as it is just a crack, but it is likely a problem. Exhaust is a big thing on 2 strokes, just a little change can make a lot of difference.
 

·
Registered
Joined
·
1,669 Posts
i have an old 76 mercury trail twister with a 340 fan and it like sto bog out after it warms up(after i go wide open for a few min)...any sugestions!
 

·
Registered
Joined
·
10 Posts
el tigre

Perhaps your 440 doesn't like sucking exhaust fumes into the carb. Engines like Oxygen not CO2 and CO.

Old Cheetah
 

·
Registered
Joined
·
187 Posts
OK I love this old sled stuff. My 73 tx 440 free air is running on the old 400 muffler if you want to call it that, it is very loud and has very little but does have some back pressure,it has no problem idling and very responsive throttle,have you checked your carbs choke or when was the last time you rebuild the fuel pump, we started having a problem with my sled after about 1/2 hour of running and found the pump wasn't working right.As for your exhaust leak yes fix it do you have a mig welder that would be your best bet.Is your gas tank clean is the pickup tube clear can you see your gas flow in your lines check these and let us know.
 
1 - 5 of 5 Posts
Top