Need to figure out my 02 SRX 700 hard starting!

MURDER YAMAHA said:
Ebay
www.ebay.com

1998 Yamaha Srx 700 Carburetors Carbs Rack | eBay

<p dir="ltr" style="margin-top:0; margin-bottom:0;">1998 Yamaha Srx 700 Carburetors, may need a good cleaning, inside of bowls looks to be in good condition </p>
www.ebay.com
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Yeah I browsed the ebay selection. A whole carb rack for roughly $100 is cheap enough but not sure I need another one. The carb rack on the sled is in good overall shape just not the best with cold starts or if the sled has sat a while. After trying the Ultra sonic cleaner on my spare set of carbs and having it discolor them so badly I'm not sure I want to do that to this set. I may just pull them off again and take everything apart as far as I can and chase a bunch of carb cleaner through everything or let them soak in my parts cleaner. It may not work quite as well as the ultra sonic cleaner but I've never had carbs discolor with those. If this fails I'll probably add a primer.
 
74Nitro said:
What about adding a boat type in line primer between the tank and pump.
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Decades ago I tried everything on my 2002 SRX to combat the hard starting issues after it sat for a week or so with limited success. I tried a SXR Red Head fuel pump, Viper carb bodies ect ect. The sled was ported with numerous mods and I ended up adapting and installing racked XCR 800 Carbs that were bored to 40.5mm. After installing the Polaris flat slide carbs it started much better as I think the choke circuit on the Polaris carbs was much more effective.
Seems to me the bulb primer was discussed and there was controversy over whether the fuel pump would resist having fuel being pumped through it and could damage the diaphragm?? But I do remember some people did it but don't know their results.
 
sideshowBob said:
Decades ago I tried everything on my 2002 SRX to combat the hard starting issues after it sat for a week or so with limited success. I tried a SXR Red Head fuel pump, Viper carb bodies ect ect. The sled was ported with numerous mods and I ended up adapting and installing racked XCR 800 Carbs that were bored to 40.5mm. After installing the Polaris flat slide carbs it started much better as I think the choke circuit on the Polaris carbs was much more effective.
Seems to me the bulb primer was discussed and there was controversy over whether the fuel pump would resist having fuel being pumped through it and could damage the diaphragm?? But I do remember some people did it but don't know their results.
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Maybe I did mention it before and forgot.
I'd still like to get to the bottom of this, clearly there's something we're missing.
 
74Nitro said:
Maybe I did mention it before and forgot.
I'd still like to get to the bottom of this, clearly there's something we're missing.
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I think you may have solved it when you stated earlier that the original 1998 SRXs did not have the hard starting issue and you stated the choke tubes were larger and Yamaha changed them due to fouling plugs.
A friend of mine had [still has] an original 1998 SRX that was bullet proof, easy starting, fast ect but would occasionally foul the OEM BR10ECS plugs...changing to BR9ES plugs solved the fouling problems.
 
sideshowBob said:
I think you may have solved it when you stated earlier that the original 1998 SRXs did not have the hard starting issue and you stated the choke tubes were larger and Yamaha changed them due to fouling plugs.
A friend of mine had [still has] an original 1998 SRX that was bullet proof, easy starting, fast ect but would occasionally foul the OEM BR10ECS plugs...changing to BR9ES plugs solved the fouling problems.
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It explains that, but this guys sled shouldn't take 20 pulls after sitting for a couple weeks.
For some reason they take a lot more pulls as they age.
 
We finally received some snow here a few weeks ago and naturally it had to get really cold and windy immediately after. The first weekend was a bust with negative, double digit temperatures and 30-50 mph winds adding to that. Surprisingly the snow was still decent for the following weekend but we were looking at temperatures below zero to only a couple degrees above. To be on the safe side I decided to throw in the 01 srx jetting specs that are a step richer. If you follow along through this whole post you you'll know I had cleaned the carbs very thoroughly and things got much better but not what it should be. In the meantime while waiting for snow the sled sat with a couple gallons of race gas in it. I do that because the shelf life of race gas is far better than todays pump gas. As I went to install the larger 01 spec main jets I noticed everything in the bowls looked brand new and ridiculously clean. Even the plastic parts looked new again. The little plastic washer that goes around the main jet went from a dark tan to a bright white. It was like the race gas sitting in the carbs over a few months had done some additional cleaning. It's only been a couple weeks of testing but the SRX has been starting 1-3 pulls every time. I rode last weekend and it sat until this Saturday and it started 1st pull. I don't know if it's possible but it seems like having the race gas in the carbs and running it periodically has worked it's way through the choke circuit and cleaned the passages out.
 
yamisrx said:
We finally received some snow here a few weeks ago and naturally it had to get really cold and windy immediately after. The first weekend was a bust with negative, double digit temperatures and 30-50 mph winds adding to that. Surprisingly the snow was still decent for the following weekend but we were looking at temperatures below zero to only a couple degrees above. To be on the safe side I decided to throw in the 01 srx jetting specs that are a step richer. If you follow along through this whole post you you'll know I had cleaned the carbs very thoroughly and things got much better but not what it should be. In the meantime while waiting for snow the sled sat with a couple gallons of race gas in it. I do that because the shelf life of race gas is far better than todays pump gas. As I went to install the larger 01 spec main jets I noticed everything in the bowls looked brand new and ridiculously clean. Even the plastic parts looked new again. The little plastic washer that goes around the main jet went from a dark tan to a bright white. It was like the race gas sitting in the carbs over a few months had done some additional cleaning. It's only been a couple weeks of testing but the SRX has been starting 1-3 pulls every time. I rode last weekend and it sat until this Saturday and it started 1st pull. I don't know if it's possible but it seems like having the race gas in the carbs and running it periodically has worked it's way through the choke circuit and cleaned the passages out.
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Hopefully you've solved it. I had a rack of carbs in my hands this week so I was looking for additional causes of this. I am now wondering if the rubber caps on the choke plungers may not be sealing as they get older. Something to look for anyway. If they were to let air in, it could take away from the vacuum required to pull the fuel through the choke circuit.
If I have a hard starter come through I'll try the race gas like you did.
 
Do you mind saying what race gas you used? Wouldn't mind knowing just for future if needed. I do have some VP VPR for my dirt bike, but they recommend draining float bowl ever time, so not sure all race gases would be good for this. Hopefully that solved it though!
 
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Yzed608 said:
Do you mind saying what race gas you used? Wouldn't mind knowing just for future if needed. I do have some VP VPR for my dirt bike, but they recommend draining float bowl ever time, so not sure all race gases would be good for this. Hopefully that solved it though!
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I had some Sunoco 110 in it this summer. I found out I could get Turbo Blue 110 closer to me a little cheaper but that looks to be the same packaging as the Sunoco with a different name.
 
74Nitro said:
Hopefully you've solved it. I had a rack of carbs in my hands this week so I was looking for additional causes of this. I am now wondering if the rubber caps on the choke plungers may not be sealing as they get older. Something to look for anyway. If they were to let air in, it could take away from the vacuum required to pull the fuel through the choke circuit.
If I have a hard starter come through I'll try the race gas like you did.
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Yes that could be something to think about. I only got to ride the machine a couple weekends in January this year. It sat two months now untouched and I started it here the other day. It was sitting in my 45 degree shop and it tried to fire after 6 pulls and came to life on the 7th. I had the fuel valve off the entire time it was sitting. I'm good with that and I think I must have found something along the way.
 
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