Hi guys, first and foremost, i'm a newbie to the forums, this will be my first post! I recently purchased a 03 foreman 450 4x4 es. it didn't run but was said to have a fairly recent (a year ago) rebuild. i can see fresh gaskets all over the engine which sort of supports the rebuild. anyway, here's my issue:
I live closer to 600 ft above sea level and have cleaned and recleaned and cleaned again the carb and put brand new Keihin jets in every spot, placed clip on the 3rd slot, as well as a new choke needle....this is a factory set carb. I have a new, clean Uni filter inside the box, and it has an hmf muffler.
When attempting to start and idle, it would lean puff and spit and die without always using a little bit of choke. swapped pilot up to a 52 and now, with choke, it will start and after warmed up, idle without the choke. however, with a stock 130 main jet it boggs at what I perceive as mid rev range. if I pull the air box lid off the rev goes higher but still not the limiter. If I pull the air filter off, it will hit the limiter. this to me says i'm way rich, but it's odd that i'm using stock keihin jets with hmf pipe and running rich. i've installed a 128 main and it's a little better still, but still will not hit the limiter with the filter on and for sure spits and sputters with the lid on the box.
i've checked valve clearances and are dead on. i've done a compression check and turned up 170 psi without loosening the exhaust valve, so compression seems good, and doesn't seem to leak down through the valves.
what am i missing?
without the air filter or lid on, i did a wot run through 4th gear and killed the engine. pulled the plug and cut the threads down, the porcelain is a very soft peach/tan color which i would say is probably perfect.
so why does my engine require less than factory fuel considering mods?
sorry for the long post but I like to be thorough. i'm definitely not a newbie to carb tuning, i rather enjoy it. but I just want to know if there is something I am missing as I am new to this particular machine
thank you all in advance
I live closer to 600 ft above sea level and have cleaned and recleaned and cleaned again the carb and put brand new Keihin jets in every spot, placed clip on the 3rd slot, as well as a new choke needle....this is a factory set carb. I have a new, clean Uni filter inside the box, and it has an hmf muffler.
When attempting to start and idle, it would lean puff and spit and die without always using a little bit of choke. swapped pilot up to a 52 and now, with choke, it will start and after warmed up, idle without the choke. however, with a stock 130 main jet it boggs at what I perceive as mid rev range. if I pull the air box lid off the rev goes higher but still not the limiter. If I pull the air filter off, it will hit the limiter. this to me says i'm way rich, but it's odd that i'm using stock keihin jets with hmf pipe and running rich. i've installed a 128 main and it's a little better still, but still will not hit the limiter with the filter on and for sure spits and sputters with the lid on the box.
i've checked valve clearances and are dead on. i've done a compression check and turned up 170 psi without loosening the exhaust valve, so compression seems good, and doesn't seem to leak down through the valves.
what am i missing?
without the air filter or lid on, i did a wot run through 4th gear and killed the engine. pulled the plug and cut the threads down, the porcelain is a very soft peach/tan color which i would say is probably perfect.
so why does my engine require less than factory fuel considering mods?
sorry for the long post but I like to be thorough. i'm definitely not a newbie to carb tuning, i rather enjoy it. but I just want to know if there is something I am missing as I am new to this particular machine
thank you all in advance