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Discussion Starter #1
I love my 95 ZR700, I finally got to take it for a ride during the blizzard we had on Long Island a few days ago. As I read more about this sled, I frequently see the only major complaint from others is the poor gas mileage it gets. I was wondering if anybody has done a carb to EFI conversion, maybe from a same year and make EFI equipted sled, like a wildcat. Has anybody ever done a conversion like this before? Will there be enough of an improvement in mileage to make it worth my time?
 

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Leave it carbed. EFI adds a lot of extra weight and electronics and it's famous for failing. You won't get any noticable mileage gains over carbs. You'll have more power with carbs too.
 

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Leave it carbed. EFI adds a lot of extra weight and electronics and it's famous for failing. You won't get any noticable mileage gains over carbs. You'll have more power with carbs too.
I'll disagree with your statement.
EFI does not add any appreciable weight and will be more efficient than carbs.
It is very reliable too.
I get better mileage than the equivalent carbed engine does.
On a day of hard riding, I am getting 14mpg and the carbed sleds are doing 10/11mpg.
 

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NO it cant be done! The EFI sleds have a differnt crank! Tank is different as well as ECU! You'd be better off selling yours to get an EFI!
 

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I think the crankcase and crank would be the same, (same part numbers on the 95 ZR 700 and the 96 Wildcat EFI), but the stator is totally different. You would need the fuel tank and in-tank fuel pump like KCCats stated, as well as the computer, wiring harness, throttle bodies, air temperature sensor, water temperature sensor, throttle position sensor, and hope the ignition timing sensor, injector timing sensor, and barometric pressure sensors are all working correctly. To get these parts new would cost you more than the value of the sled, so you would be looking for a donor sled to get the hardware economically. I totally agree with KCCats, you would be much better off selling your sled and getting an EFI.

I had a 94 carb ZR and a 95 EFI ZR, the EFI consistantly got better fuel mileage (9 vs. 10) but the carb would outrun it on most days. I had no issues ever with any of the electronics on the EFI, it was a very reliable sled.
 

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Discussion Starter #6
Ok well I will definatley NOT be attempting any conversion! Just buy a newer EFi equipted sled for next season. Thanks for the input guys!
 

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It's very possible you can get better fuel mileage from your sled with a little maintenance. Start by checking all the bearings in the bogey wheels. A stuck or frozen bearing will rob you of power big time. If you really want to do some work, change out the bearing grease to synthetic; the bearings will have less rolling resistance and more HP to the track. Make sure the track is aligned and then align the skis to the track. The skis should have no more than 1/4" toe out for best performance.

Make sure the clutch sheaves are clean and not shiny. Use some emery cloth or a green scotch-brite pad to scuff the sheaves and the sheaves will be able to grip the belt better. No slippage = more HP to the track. Also, scrub the sides of the belt for the same reason. Then make sure the alignment from the primary to secondary is perfect; any misalignment in the offset will really rob HP.

What kind of lube are you running in the chaincase? If you're not running synthetic chaincase fluid, you could benefit by changing oil, especially if you are using a gear lube. The thinner fluid designed for chaincases will give you the lubrication you require but not the additional friction that comes with a thicker oil.

How is your jetting? Do a WOT plug chop; if your plugs are black, you can safely rejet to smaller jets, thus getting better fuel mileage. After you figure the best jet for WOT, then do the same plug check at mid-throttle to check and see if you can lower the needle. If your mid-range shows black plugs, you can lower the needle a notch without damaging anything and again, gain better fuel mileage.

Check for any fuel leaks in hoses, fuel pump, impulse line. Any fuel that is not being burned by the engine is definitely not giving you any power/mgp. I had a buddy that had a sled that was getting HORRIBLE mpg, he found the water trap hose on the bottom of the carb was cracked and was leaking fuel the whole time he was riding! He's lucky he didn't have a fire to go with his poor fuel mileage!!

700's were not known for their awesome fuel mileage, but you may be able to get another 1-2 mpg out of your sled with a little work and attention to detail. I'm betting 8-9 and maybe even 10 is reasonable to achieve without a ton of money spent.
 

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Resurrection for Justice.

Go ahead but you're wrong. You have a biased opinion anyway. The facts are the EFI would add extra weight and have less power than the carbed version.
This is perhaps one of the most ignorant comments I've ever heard. Yeah EFI is just a terrible Idea. That must be why every automobile manufacturer on the planet adopted it as their only means of fuel delivery IN THE 1980's. Carbs have been an obsolete fueling technology for decades. If you are a snowmobile enthusiast that's not scared of the world beyond bolt on parts look into Microsquirt and/or Speeduino. It will cost some money but when you're sled starts on the first pull on that -20 degree day you'll have something cool to be proud of.

P.S. the weight addition of EFI parts couldn't possibly add more than 2lbs unless you were going to retrofit the injection pump from an 18 wheeler or something lol.
 

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You have to realize, this is a 10 year old thread. Back in the early EFI days in snowmobiles, EFI was often VERY problematic. Cat was better than Polaris, but not by much! Couple that with a better understanding regarding carburetors and it was easy to see how you could tune carbs to outrun a similar EFI sled.


Fast forward 10 years and the EFI technology has caught up to the durability of carbs. I'm down to four sleds, and 3 of them are EFI. The good part... I've never had any EFI issues on any of those three. The bad part... if I do, there's no easy way for me to do the necessary troubleshooting without the specific Polaris diagnostic tools. At least with carbs, you could work on stuff! With EFI... you just ride. Hmm.. I kind of like that ;)


Welcome to the forum!
 

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I am a Big fan of EFI
Problem is Polaris tried and failed and it gave most a bad impression of EFI

Cat has had it down since the Batteryless of 97
 

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You have to realize, this is a 10 year old thread. Back in the early EFI days in snowmobiles, EFI was often VERY problematic. Cat was better than Polaris, but not by much! Couple that with a better understanding regarding carburetors and it was easy to see how you could tune carbs to outrun a similar EFI sled.


Fast forward 10 years and the EFI technology has caught up to the durability of carbs. I'm down to four sleds, and 3 of them are EFI. The good part... I've never had any EFI issues on any of those three. The bad part... if I do, there's no easy way for me to do the necessary troubleshooting without the specific Polaris diagnostic tools. At least with carbs, you could work on stuff! With EFI... you just ride. Hmm.. I kind of like that ;)


Welcome to the forum!
Thanks Man!
I'm more of a Yamaha guy myself but that's because I've migrated from the motocross world. I hear your point and I do feel a bit dumb for getting angry over a 10 year old thread. To clarify, I understand that (at the time) carbs were a far wiser choice than EFI BUT I can't stand when somebody so harshly puts down someone else's creativity in the power sports world. I am neck deep in an EFI conversion on my 95 yamaha vmax 600 right now and it is not only fun, but one of the most rewarding mechanical projects I've done. In the interest of full disclosure I just don't want anyone to get discouraged from trying something new with their sled.
 

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It's always awesome when folks try things and it works out for them. Most of the sled conversions went from the pitiful early EFI back to carbs, especially with Polaris. The battery type Cat EFI wasn't so great, either, although most of the problems with those were weak batteries.



There are a ton of benefits to EFI. Not having to change jetting when the temps or elevation change is number one. Mapping close to the line to always have the best power is second to that. I can see why someone would want to go EFI from carbs. But for most sled engines, there aren't many interchangeable parts between the two types and the cost to do a conversion would exceed the value of the sled. It may not exceed the educational value, though! And that doesn't take into account the fun factor, either.


I think a lot of us on here like watching such projects, especially if there are plenty of pictures to guide us along. I know I always like watching someone other than me working on sleds ;)
 

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The problem is the flywheel on the early where different!

The newer efi is a stand alone with pick up coils

The mapping is the biggest challenge.

For a 600 twin Vmax the 600 Cat would work fine, I would add My fuel pressure Regulator on it as to be able to tune it

For the Vmax 4 two sets!

Cat never did make a triple EFI and I bet Polaris wishes they never did!
 

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You have to realize, this is a 10 year old thread. Back in the early EFI days in snowmobiles, EFI was often VERY problematic. Cat was better than Polaris, but not by much! Couple that with a better understanding regarding carburetors and it was easy to see how you could tune carbs to outrun a similar EFI sled.


Fast forward 10 years and the EFI technology has caught up to the durability of carbs. I'm down to four sleds, and 3 of them are EFI. The good part... I've never had any EFI issues on any of those three. The bad part... if I do, there's no easy way for me to do the necessary troubleshooting without the specific Polaris diagnostic tools. At least with carbs, you could work on stuff! With EFI... you just ride. Hmm.. I kind of like that ;)


Welcome to the forum!
I would love to find out more about your EFI conversion on your Yami. I've been thinking about doing the same thing myself but didn't know where to begin. I have a '97 700 SX. Let me know if you'd like to talk.
 

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Well believe it because it isn't possible on a older sled like that. There is a reason why people with a Polaris EFI usually switched them to the carb version. The EFI back then absolutely sucked. Parts constantly would break down, they were expensive as well not too mention trying to figure out what was wrong was damn near impossible even today on that system. I should know I have a '92 Indy 500 EFI and I am seriously considering switching it to carb because of those reasons. Every time I get it running correctly within a month something else goes wrong with the EFI system.
 
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