350 to 400 cylinder swap
Sep 27, 2006 | 03:40 PM
#31
Pro Rider
Joined: Sep 2003
Posts: 774
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350 to 400 cylinder swap
I scrapped the stock fuel valve. Im running a 5/16 line with a mikuni vaccuum fuel pump. And I still has fuel starvation issues, until i re-did the tank. But thats with a 44mm lectron setup for alcahol.
Sep 27, 2006 | 08:05 PM
#33
Range Rover
Joined: May 2003
Posts: 108
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350 to 400 cylinder swap
Originally posted by: mrtwostroke
I didn't know that the 350 had intake boost ports, the first few years of the 400 didn't, but in 96 when the engine were started to be produced by robin of the usa instead of fuji heavy industries they then had them. i can only assume that the switch from fuji to robin had something to do with the lawsuit fuji and polaris had against. IRS (injection research specialists) sued them both for stealing their two-stroke injection for snowmobiles. anyway back to the cylinders. the majority of you think think that the boost ports gave more power. well my opinion was that in stock forom the ones without felt better to me. case in point our old 91 350 trail boss than our 94 sportsman 400 would always beat our 96 sportsman 400. Is this normal. any way a question for rick ritter is anyone using fuel pumps on 400 with bigger carbs. and if so when is this necessary. My brother has a 2000 scrambler with a 432 big bore and 38 mm roundslide and he has fuel delivery problems. likes to quit after long periods of wide open throttle. espescially on less than half a tank. thanks for the help everyone
I didn't know that the 350 had intake boost ports, the first few years of the 400 didn't, but in 96 when the engine were started to be produced by robin of the usa instead of fuji heavy industries they then had them. i can only assume that the switch from fuji to robin had something to do with the lawsuit fuji and polaris had against. IRS (injection research specialists) sued them both for stealing their two-stroke injection for snowmobiles. anyway back to the cylinders. the majority of you think think that the boost ports gave more power. well my opinion was that in stock forom the ones without felt better to me. case in point our old 91 350 trail boss than our 94 sportsman 400 would always beat our 96 sportsman 400. Is this normal. any way a question for rick ritter is anyone using fuel pumps on 400 with bigger carbs. and if so when is this necessary. My brother has a 2000 scrambler with a 432 big bore and 38 mm roundslide and he has fuel delivery problems. likes to quit after long periods of wide open throttle. espescially on less than half a tank. thanks for the help everyone
My husband has built 3- 350's and 2- 400's. One 350 will run 5.0's in 300 ft and one will run 3.7's in 200ft. Havent been to a 300ft track with it as of yet. He is working on the other 350 which should out run them all. Then one of the 400's runs 4.8's in 300ft and the other one run 3.5's in 200ft. These are all on motor. He has built them a little differently just to see which would be the fastest. You not only have to know how to bulid them you also need to know how to tune them.
Sep 27, 2006 | 11:32 PM
#35
Pro Rider
Joined: Oct 1999
Posts: 1,268
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350 to 400 cylinder swap
A lot of the Alky guys run a pump . The 400's can get pretty thirsty when modded out . Just make sure the carb has the right needle seat in it .
And - I guess no one has a dead 350 2wd laying around ?
And - I guess no one has a dead 350 2wd laying around ?
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