EFI TO CARB CONVERSION 95 INDY 500 MOTOR - HCS Snowmobile Forums

Polaris General Discussion This is a brand-specific forum. Posts on this forum are assumed to be questions aimed at similar model owners, and are not looking for comments of a sarcastic or "bashing" nature. This is a 100% NO BASH ZONE. Please be aware that if you violate this policy you are in danger of losing your posting privileges on this website.The calling out or posting of another members personal information IE phone number or address is prohibited. Sharing of private messages from site staff is against site rules and will be subject to banning from site temporarily or permanently.

Sponsored By: Reevu Rear-Vision Helmets & Altimate Boots

Reply
 
LinkBack Thread Tools
Old 02-18-2010, 12:52 AM   #1 (permalink)
Member
 
CHAINSMOKER's Avatar
 
Join Date: Sep 2008
Posts: 11
Current Sled(s): 1998 XC 700
Previous Sled(s): 1989 INDY 500
Location: LAKE VILLA IL.
Favorite Riding Area: CHAIN O LAKES
10-11 Mileage: 60
Age: 40
Riding Since: 1995
Smile

i,m trying to convert a 95 efi motor in to carb. it runs but the carbs are flooding (excessive fuel pump pressure) the lower end is the same as a carburated engine accept the spot where you hook up the hose for the pump is not drilled out. so i tryed to drill it in the sled but i think the whole is to small. which means i have to pull the motor again and hope the shavings don't go down in to the crank. now i'm thinking i should just get a gasket set and use the other parts i have. long story short. i'm probably FU*KED until next season.
CHAINSMOKER is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 02-18-2010, 10:31 AM   #2 (permalink)
Super Advanced Member
 
D-rail's Avatar
 
Join Date: Mar 2005
Posts: 4,096
Current Sled(s): '98 XC 700 "Snowflake", 2005 Fusion Time Bomb
Previous Sled(s): Polaris, Ski-Doo, Yamadog, Rupp, G-Whiz, Scrap Iron, etc.
Location: Duluth
Favorite Riding Area: roller coaster stuff
13-14 Mileage: 3900
12-13 Mileage: 4105
11-12 Mileage: 1925
10-11 Mileage: 3205
Age: 61
Riding Since: 1973
Default

Welcome to HCS! If you drill out that hole, put a dab of grease on the flutes to grab any aluminum shavings that come out, drill a few seconds and then pull it out, clean and repeat. You running a regular (impulse style) pump then? I did this conversion to my '93 500, EFI sucked, put a set of 38's on and still got over 15 mpg, ran great. I did have to modify the boots to match the airbox and cylinder fit-up.
__________________


My wife and I were talking the other day... she said, "I'm not the crazy one, you're the crazy one, you decided to marry me.."


D-rail is offline   Reply With Quote
Old 02-18-2010, 12:55 PM   #3 (permalink)
Member
 
CHAINSMOKER's Avatar
 
Join Date: Sep 2008
Posts: 11
Current Sled(s): 1998 XC 700
Previous Sled(s): 1989 INDY 500
Location: LAKE VILLA IL.
Favorite Riding Area: CHAIN O LAKES
10-11 Mileage: 60
Age: 40
Riding Since: 1995
Default

QUOTE (D-rail @ Feb 18 2010, 10:31 AM)
Quote:
Welcome to HCS! If you drill out that hole, put a dab of grease on the flutes to grab any aluminum shavings that come out, drill a few seconds and then pull it out, clean and repeat. You running a regular (impulse style) pump then? I did this conversion to my '93 500, EFI sucked, put a set of 38's on and still got over 15 mpg, ran great. I did have to modify the boots to match the airbox and cylinder fit-up.[/b]
thanks for the advice. is the regular (impulse style) pump ok to run with this conversion? do you suppose the hole is to small and that is why i'm getting excessive gas to the carbs? no gas is coming out the over flow, the fuel air screw is adjusted 1/2 turn out, my choke is in as far as it will go w/out not being able to use it. that is the only thing i can think is causing it to flood.
thanks again D.
__________________
P.O.S. SNOWMOBILE!
CHAINSMOKER is offline   Reply With Quote
Old 02-18-2010, 01:09 PM   #4 (permalink)
Super Moderator
 
XCR1250's Avatar
 
Join Date: Oct 2005
Posts: 27,856
Current Sled(s): XCR 800
Previous Sled(s): O.M. 1000, XCR 1253, XC1214, P.S.700
Location: Sawyer county Wisconsin
Favorite Riding Area: N.W. Wisconsin
13-14 Mileage: 1,864
12-13 Mileage: 767
Riding Since: 1959
Default

No fuel screw on round slide carbs.
Why would you believe the fuel pump pressure is excessive? Did you measure it?
Pressure test the carbs, dry and wet.
XCR1250 is offline   Reply With Quote
Old 02-18-2010, 05:47 PM   #5 (permalink)
Super Advanced Member
 
D-rail's Avatar
 
Join Date: Mar 2005
Posts: 4,096
Current Sled(s): '98 XC 700 "Snowflake", 2005 Fusion Time Bomb
Previous Sled(s): Polaris, Ski-Doo, Yamadog, Rupp, G-Whiz, Scrap Iron, etc.
Location: Duluth
Favorite Riding Area: roller coaster stuff
13-14 Mileage: 3900
12-13 Mileage: 4105
11-12 Mileage: 1925
10-11 Mileage: 3205
Age: 61
Riding Since: 1973
Default

The pump used on the EFI is an electric one, it puts out more pressure than you need. Use the standard impulse style pump. What are the carbs off of? Check your jetting to match what the stock carbs had, both mains and pilots (The 1995 parts list calls for 300 sized mains, and #40 for pilots- my '93 used 280 mains). Most Mikunis are set between one and three turns out on the fuel/air screw, anything out of that range means using bigger or smaller pilots. Turn in (clockwise) to block air passage into the idle circuits, makes it run richer. Check the inlet valves, make sure they don't leak, like XCR1250 says, pressure test them.
__________________


My wife and I were talking the other day... she said, "I'm not the crazy one, you're the crazy one, you decided to marry me.."


D-rail is offline   Reply With Quote
Old 02-19-2010, 01:41 AM   #6 (permalink)
Member
 
CHAINSMOKER's Avatar
 
Join Date: Sep 2008
Posts: 11
Current Sled(s): 1998 XC 700
Previous Sled(s): 1989 INDY 500
Location: LAKE VILLA IL.
Favorite Riding Area: CHAIN O LAKES
10-11 Mileage: 60
Age: 40
Riding Since: 1995
Default

QUOTE (XCR1250 @ Feb 18 2010, 01:09 PM)
Quote:
No fuel screw on round slide carbs.
Why would you believe the fuel pump pressure is excessive? Did you measure it?
Pressure test the carbs, dry and wet.[/b]
__________________
P.O.S. SNOWMOBILE!
CHAINSMOKER is offline   Reply With Quote
Old 02-19-2010, 01:50 AM   #7 (permalink)
Member
 
CHAINSMOKER's Avatar
 
Join Date: Sep 2008
Posts: 11
Current Sled(s): 1998 XC 700
Previous Sled(s): 1989 INDY 500
Location: LAKE VILLA IL.
Favorite Riding Area: CHAIN O LAKES
10-11 Mileage: 60
Age: 40
Riding Since: 1995
Default

QUOTE (XCR1250 @ Feb 18 2010, 01:09 PM)
Quote:
No fuel screw on round slide carbs.
Why would you believe the fuel pump pressure is excessive? Did you measure it?
Pressure test the carbs, dry and wet.[/b]
carbs are flooding the motor. it wants to run but floods out. using 38 carbs. how do i ( Pressure test the carbs, dry and wet?)?.
__________________
P.O.S. SNOWMOBILE!
CHAINSMOKER is offline   Reply With Quote
Old 02-19-2010, 02:05 AM   #8 (permalink)
Member
 
CHAINSMOKER's Avatar
 
Join Date: Sep 2008
Posts: 11
Current Sled(s): 1998 XC 700
Previous Sled(s): 1989 INDY 500
Location: LAKE VILLA IL.
Favorite Riding Area: CHAIN O LAKES
10-11 Mileage: 60
Age: 40
Riding Since: 1995
Default

QUOTE (D-rail @ Feb 18 2010, 05:47 PM)
Quote:
The pump used on the EFI is an electric one, it puts out more pressure than you need. Use the standard impulse style pump. What are the carbs off of? Check your jetting to match what the stock carbs had, both mains and pilots (The 1995 parts list calls for 300 sized mains, and #40 for pilots- my '93 used 280 mains). Most Mikunis are set between one and three turns out on the fuel/air screw, anything out of that range means using bigger or smaller pilots. Turn in (clockwise) to block air passage into the idle circuits, makes it run richer. Check the inlet valves, make sure they don't leak, like XCR1250 says, pressure test them.[/b]
no carbs. was efi. trying to convert to carb. no pulsater hook up had to drill out & add hook up. went from no gas to too much gas.270 jets or is it 240? getting ready to get a full gasket kit,use extra parts & ride next year. unless another snowstorm comes this way.
__________________
P.O.S. SNOWMOBILE!
CHAINSMOKER is offline   Reply With Quote
Old 02-19-2010, 10:00 AM   #9 (permalink)
Member
 
CHAINSMOKER's Avatar
 
Join Date: Sep 2008
Posts: 11
Current Sled(s): 1998 XC 700
Previous Sled(s): 1989 INDY 500
Location: LAKE VILLA IL.
Favorite Riding Area: CHAIN O LAKES
10-11 Mileage: 60
Age: 40
Riding Since: 1995
Default

QUOTE (CHAINSMOKER @ Feb 19 2010, 02:05 AM)
Quote:
no carbs. was efi. trying to convert to carb. no pulsater hook up had to drill out & add hook up. went from no gas to too much gas.270 jets or is it 240? getting ready to get a full gasket kit,use extra parts & ride next year. unless another snowstorm comes this way.[/b]
__________________
P.O.S. SNOWMOBILE!
CHAINSMOKER is offline   Reply With Quote
Old 02-19-2010, 10:08 AM   #10 (permalink)
Member
 
CHAINSMOKER's Avatar
 
Join Date: Sep 2008
Posts: 11
Current Sled(s): 1998 XC 700
Previous Sled(s): 1989 INDY 500
Location: LAKE VILLA IL.
Favorite Riding Area: CHAIN O LAKES
10-11 Mileage: 60
Age: 40
Riding Since: 1995
Default

QUOTE (D-rail @ Feb 18 2010, 05:47 PM)
Quote:
The pump used on the EFI is an electric one, it puts out more pressure than you need. Use the standard impulse style pump. What are the carbs off of? Check your jetting to match what the stock carbs had, both mains and pilots (The 1995 parts list calls for 300 sized mains, and #40 for pilots- my '93 used 280 mains). Most Mikunis are set between one and three turns out on the fuel/air screw, anything out of that range means using bigger or smaller pilots. Turn in (clockwise) to block air passage into the idle circuits, makes it run richer. Check the inlet valves, make sure they don't leak, like XCR1250 says, pressure test them.[/b]
i turned the f/a screws out 3 turns got it to run. speedo doesn't work but it seems like i can only get her up to 30-35 mph. w/idle screws all in it's idling at about 1k rpm barley running. smoking a lot i'm thinking too much oil? don't want to lean her out too much & blow it.
__________________
P.O.S. SNOWMOBILE!
CHAINSMOKER is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 05:36 AM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0