Honda Foreman Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
Hey Everyone! I have a problem that I cant seem to figure out. Ill start of with details. 2001 Honda Foreman 450 - 3300 miles.

For some reason while I'm riding the bike will start making a hissing sound in the front and the exaust will stop making noise. While this is happening it will bog down and loose power and sometimes even slow to a crawl and stall. Sometimes if I let off the throttle or flutter the choke while this is happening it will start running fine again for a short time. The hissing in the front sounds like someone put their hand over the air intake and the exaust literally goes silent like it was plugged. The first thing I thought was it must be the carb. I have made sure that all the fuel is flowing fine up to the carb. I took the bike to a mechanic and had him give a really good cleaning to the carb and make adjustments to the valves. I have cleaned the air filter and checked the spark plug. Everything seems fine. It really seems like something is plugging up every time it boggs down. I had the mechanic take off the muffler to see if maybe that was the problem, ( something like a rock that bounces around and plugs the exaust from time to time I thought ) The muffler is full of rocks and metal peices. I had tried to run the bike while the muffler drain was open but nothing came out. Anyway, I was wondering if anyone has any idea of what it could be and also if i should replace the muffler. Thanks for your help
 

·
Registered
Joined
·
3 Posts
Giving it a little choke to keep the bike running generally means that you have a manifold vacuum leak at the carb. This is quite common on the 70's Honda minibikes that I am addicted to repairing - a psychiatric malady that has yet to get the proper attention it so richly deserves in the medical literature.

Think about it - giving it some choke richens up the fuel mixture to compensate for the unmetered lean air getting in at the manifold. It is possible that the carb flange is warped, the intake manifold flange is warped or if there is an o-ring there, the o-ring and gasket should be replaced. Controversially, I use just a dab of non hardening Permatex gasket sealer here to somewhat prevent vacuum leaks. It is controversial because most Honda shop manuals do not call for the use of gasket sealer.

You can check for a vacuum leak very easily. Get the motor to at least idle, if possible. Then spray some carb cleaner at the flanges. Does the engine RPM change? If so, fix your vacuum leak. Propane from an unlit propane torch can also be used here.

You can sand your carb flange or manifold flange flat using heavy sandpaper on a piece of plate glass.

Rick
Bossier City, Louisiana
 

·
Registered
Joined
·
6 Posts
Discussion Starter #3
Well I guess I should say that when I do put on the choke it is only for a split second and then i shut it off. It may be a coincidence that it stops bogging at this point but it could also be that I let off the throttle. If i put the choke on even a bit while it is running it will stall so I dont think that this is the problem. When the mechanic had the bike he took the exaust off. It is full of broken pieces. Is it possible that these pieces are blocking the air flow? Have you ever heard of a muffler causing running problems?
 

·
Premium Member
Joined
·
2,427 Posts
the muffler could cause issues if its clogged up and isn't flowing properly... mine was clogged and it robbed alot of power from mine. too much back pressure
 

·
Registered
Joined
·
6 Posts
Discussion Starter #5
Bogging out and loss of power

Tea time- Did yours do this suddenly or was it plugging occasionally until it finally plugged for good?
 

·
Premium Member
Joined
·
2,427 Posts
it had been plugged since i bought the bike from the orig. owner... couldn't understand why the machine was so gutless, thought thats how it was supposed to run but i saw night and day difference once i piped it...
 

·
Registered
Joined
·
2 Posts
Hey Everyone! I have a problem that I cant seem to figure out. Ill start of with details. 2001 Honda Foreman 450 - 3300 miles.

For some reason while I'm riding the bike will start making a hissing sound in the front and the exaust will stop making noise. While this is happening it will bog down and loose power and sometimes even slow to a crawl and stall. Sometimes if I let off the throttle or flutter the choke while this is happening it will start running fine again for a short time. The hissing in the front sounds like someone put their hand over the air intake and the exaust literally goes silent like it was plugged. The first thing I thought was it must be the carb. I have made sure that all the fuel is flowing fine up to the carb. I took the bike to a mechanic and had him give a really good cleaning to the carb and make adjustments to the valves. I have cleaned the air filter and checked the spark plug. Everything seems fine. It really seems like something is plugging up every time it boggs down. I had the mechanic take off the muffler to see if maybe that was the problem, ( something like a rock that bounces around and plugs the exaust from time to time I thought ) The muffler is full of rocks and metal peices. I had tried to run the bike while the muffler drain was open but nothing came out. Anyway, I was wondering if anyone has any idea of what it could be and also if i should replace the muffler. Thanks for your hDid you ever figure
Well I guess I should say that when I do put on the choke it is only for a split second and then i shut it off. It may be a coincidence that it stops bogging at this point but it could also be that I let off the throttle. If i put the choke on even a bit while it is running it will stall so I dont think that this is the problem. When the mechanic had the bike he took the exaust off. It is full of broken pieces. Is it possible that these pieces are blocking the air flow? Have you ever heard of a muffler causing running problems?
Did you ever figure out what this was. I ha e one that does the exact same thing.
 
1 - 11 of 11 Posts
Top