nitrosport_5
New Member
Hi, i am not a Seadoo Owner/rider, nor am i a Skidoo owner/rider but i happen to own parts from each... lol anyways.
I am builing/restoring a 1989 FL400 Honda Pilot ATV with a 1998 Skidoo Summit X 670HO engine. To get the engine to sit down lower in the chassis and to make throttle pull much easier, i was led to the downdraft carbs from the SeaDoo. the carbs that i have are a pair of Mikuni BNi 38's. As you can tell its a bit of a frankenstein, but once i get everything tuned it should be a fun toy.
Anyways, what i was hoping to accomplish here is to possibly get a good/close baseline jetting/needle setting from someone that knows these carburetors better than i do. I was able to get it running by playing with the needles a little. It really is hard to start, have to use the primer just right, but once it starts and i rev iit passed a certain RPM the throttle response is much better, but it is fairly rich on the top end. Once it gets down to the lower RPMS again it is just boggy and extremely hard to bring the RPMS back up, most of the time it just dies.
Currently the carburetor is setup as follows
67.5 Pilot Jet
130 Main jet
2 turns out on the high speed
2.5 turns out on the low
Im fairly certain that it is running extremely rich, because there is a ton of oil coming out of the pipe. Just happened to coat my whole toolbox lol. It alsso is smoking like a SOB. But on the low end i think it is possibly running lean because it is extremely hard to start, and very boggy down low.
Im wondering if it is also getting too much oil. The oil pump that came with the Skidoo 670 has a 6, or a 9 on the back of it and had a larger gear on it than the Seadoo pump. I used the Seadoo gear with the stock 670 pump. Could the smaller gear from the seadoo pump be spinning the stock 670 pump too fast making it pump too much oil? Should i start using the pump from the seadoo? It had a 5 on the back of it.
Thanks in advance for any help. I know this is kindof an odd request, but i thought maybe based on the CC of the engine someone could point me to a place to star that is better than what i have currently.
Here are a couple photos of it so you can see what i am working on. The first picture is what it looked like when i bought it on ebay. Had it shipped from Alabama to Washington. It sat where you see it for 10 years or more. the second picture is a work in progress, hoping to get it running better before i put all of my fenders and final touches on.
I am builing/restoring a 1989 FL400 Honda Pilot ATV with a 1998 Skidoo Summit X 670HO engine. To get the engine to sit down lower in the chassis and to make throttle pull much easier, i was led to the downdraft carbs from the SeaDoo. the carbs that i have are a pair of Mikuni BNi 38's. As you can tell its a bit of a frankenstein, but once i get everything tuned it should be a fun toy.
Anyways, what i was hoping to accomplish here is to possibly get a good/close baseline jetting/needle setting from someone that knows these carburetors better than i do. I was able to get it running by playing with the needles a little. It really is hard to start, have to use the primer just right, but once it starts and i rev iit passed a certain RPM the throttle response is much better, but it is fairly rich on the top end. Once it gets down to the lower RPMS again it is just boggy and extremely hard to bring the RPMS back up, most of the time it just dies.
Currently the carburetor is setup as follows
67.5 Pilot Jet
130 Main jet
2 turns out on the high speed
2.5 turns out on the low
Im fairly certain that it is running extremely rich, because there is a ton of oil coming out of the pipe. Just happened to coat my whole toolbox lol. It alsso is smoking like a SOB. But on the low end i think it is possibly running lean because it is extremely hard to start, and very boggy down low.
Im wondering if it is also getting too much oil. The oil pump that came with the Skidoo 670 has a 6, or a 9 on the back of it and had a larger gear on it than the Seadoo pump. I used the Seadoo gear with the stock 670 pump. Could the smaller gear from the seadoo pump be spinning the stock 670 pump too fast making it pump too much oil? Should i start using the pump from the seadoo? It had a 5 on the back of it.
Thanks in advance for any help. I know this is kindof an odd request, but i thought maybe based on the CC of the engine someone could point me to a place to star that is better than what i have currently.
Here are a couple photos of it so you can see what i am working on. The first picture is what it looked like when i bought it on ebay. Had it shipped from Alabama to Washington. It sat where you see it for 10 years or more. the second picture is a work in progress, hoping to get it running better before i put all of my fenders and final touches on.
