sleddineinar
VIP Member
My Vmax 700sx is piped, I run the same jets on all 3 cyls, but the #1 or PTO is always fouling out. I've been dealing with this for a while now. But just changing plug every other ride is getting old. I've swapped the plug wires around and the seals have been replaced. The reeds all look the same, last year I swapped the reeds around even. I've noticed that the nozzle on the #1 is a Q8 whereas #2 & #3 are a Q4. Will replacing the nozzle in #1 with a Q4, be a good idea? Will I need to watch for anything else when I swap it? I recently had the head off to fix a head gasket problem and the top of cyl #1 is completely washed off, while the tops of #2 & #3 look OK, possibly a little dry, so I might raise the needles on them a little. I didn't take pictures while I had it apart. Any advice or thoughts would be welcome.
what plugs are you running? the reason i ask is because i had similer problem with mine until i went to br9eya's. I have not fouled a plug in 8 years
sleddineinar
VIP Member
I've tried a few different plugs. BR9EYA, BR9ECS, BR9ES, even BR8ES. I have similar results except the the 8s last longer. They all look really rich on the #1 plug. Currently I have a BR9EYA in the #1 spot, last weekend I fouled the BR9ECS.
chris700readhead
Member
I have to run mine a clip leaner on the needle for #1 to keep the plugs all the same. If you change the nozzle you will be able to set all the carbs the same and be good to go.
sleddineinar said:
When I picked up my sled the PO had EYA's in them. Only advantage I could see to those is to advance the timing just a smidge if at all because the plug tip extends a bit more into the combustion chamber. Less distance=less time=advance.
I like the Iridium plugs with the fine wire center electrode. BR9EIX.
Fairly expensive, but shop around. Good stuff. NGK used to have a non-iridium version that I used in everything from cars to dirt bikes, to sleds until they stopped making them. EV I believe? They were really cheap.
I have NEVER fouled anything with a fine wire center electrode. Including an old beater car that I had with leaking valve seals that would foul other plugs no problem. These will come right back after being soaked, at least mine did.
Honestly, come to think of it, I've never even heard of a fine wire plug fouling.....
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SX600abuser
Member
Find out where you are running fat at....WOT, 1/2 throttle?....I am sure you are probably running fat everywhere except maybe full throttle, in which case, yes, definetly swap the Q8 to a Q6 or maybe a Q4.
Those are basically your midrange jets as they meter the fuel when the needle is lower than WOT.
Those are basically your midrange jets as they meter the fuel when the needle is lower than WOT.
sleddineinar
VIP Member
I picked up a Q4 from my dealer and installed it today. I will be doing some testing latter this week, to see how the plugs look. Just for the record, I'm using older CPR/Hauck pipes with stingers, the jets are 148.8s, 47.5s and the needles are in the middle position with both washers under. Now I have Q4s all the way across.
sleddineinar
VIP Member
I put the Q4 in the #1 cyl. I went for a ride today. I read my plugs and after each run, all three looked just about right. What difference that makes when all three cyls are running right. in approx. 500 ft. I was hitting 80mph from a dead start on semi-hard pack. It ran awesome today! For what it's worth it was 20°F & and lovely sunny day. I put about 35-40 miles on today and you never would have guessed the season should already be over this far down in the state. The trails were bumpy, but only saw one or 2 little bare spots, where the trail was on a southern exposure. I'm going out again tomorrow.
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