Gerryjackman
New member
Does anyone know the proper plugs for a 98 mountain srx 700 I've been told to run br9ecs because they foul less than the tens but I've been fouling at least one plugs every three or four hard rides does anyone know the difference in these and the tens or even the br9ecs compared to br8ecs?
Mysledblows
VIP Member
I used the 9's for years. 10 is a cooler plug than the 9 and an 8 is hotter yet. So - I'd try the 9's.
Gerryjackman
New member
Is there any harm in running the 8's I have fouled a few 9's so far really running it hard
Mysledblows
VIP Member
Personally I'd run the 9's and figure out what the issue is that's causing you to foul plugs. I ran my 99 for years here in MN and out west and can only remember fouling one plug after the sled sat upside down in a tree for 45 minutes.
Devilin AblueDress!
New member
X2 on sticking with 9's and figuring out why? They also come in irridium or platiumn version you might have better luck with that version than going to an 8 or 10.
bluewho
Active member
Find yourself some newer style yamaha sparkplug caps and replace all 3 i would bet your fouling issues will be over.Sorry i dont know what year they changed the style but they are notacably differant in apperance.
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motorhead327
VIP Member
bluewho said:Find yourself some newer style yamaha sparkplug caps and replace all 3 i would bet your fouling issues will be over.Sorry i dont know what year they changed the style but they are notacably differant in apperance.
X2 REPLACE THOSE CAPS! Cant preach it hard enough!
95rxl650
Member
When was the last time you did a compression test?
How do the plugs and piston wash look? I agree with changing caps, made a night and day difference in idle and plug life.
Gerryjackman
New member
I put new plug caps on there Ngk I'm not sure if that matters just asked at the parts desk and that's what they gave me pulled all plugs and they all have what seems to be good spark I don't know why I'm going through them so bad my compression is a little low but all the research I've done guys say don't worry about the number just that all three are the same and they are and it also holds for sufficient amount of time compression is around 110 a little low I know but seems to still haul *** when not in deep powder. Another concern I had was the jetting but I cannot find what jets there suppose to be in there for my riding elevation I started a thread on that and kinda got nowhere any help would be awesome. I'm in te middle of getting a different altitude compensator because I was in the mountains when I was having most of my issues but in order for the compensator to work correctly the jetting has to be bang on. Any more help is greatly appreciated thanks guys
Gerryjackman
New member
Why do you ask the last time I did a compression test?
bluewho
Active member
From experance not speculation the ngk caps are not any good for these sleds.Yamaha did a upgrade for a reason as i see it .If you moter is fouling the plugs they should be black when you pull them out.
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Gerryjackman
New member
I'm not a hundred percent sure if there fouling or what but I know they don't work after a few rides at least one is down there not black as u say but definitely not the way they should be would changing caps really make that big of difference? Any other possibilities I'm still wondering why someone chimed in about compression ?
Devilin AblueDress!
New member
Gerryjackman said:I'm not a hundred percent sure if there fouling or what but I know they don't work after a few rides at least one is down there not black as u say but definitely not the way they should be would changing caps really make that big of difference? Any other possibilities I'm still wondering why someone chimed in about compression ?
A cylinder low on compression wont fire as it should, not firing as it should would foul a plug. You said all three 110 so I doubt thats your issue. I would double check them caps. What ever brand/part number you go with 5k ressistance is the key element. I say this as when I went looking I had 3 "snowmobile shops" try to sell me caps for newer 4 stroke sleds with 10k resistors. Entirely possible they sold you wrong caps. Theres ben a TON of threads of guys chasing phantom weird intermitten and/or regular problems until in a last ditch effort swapped caps and WAHLAA!
Devilin AblueDress!
New member
Another question, You say at least 1 cylinder down? Is it always the same cylinder? Do you know which one it is?
Gerryjackman
New member
I dont recall it being the same cylinder but I could be mistaken I thought plugs may be bad so I through in new ones and worked great for a while maybe put on 200k and then idle gets a bit off and I can tell its happenning. Jus changed them all never paid attention next time I will. What kind of caps should I be looking for any specific brand or make?
carb condition? all clean and good to go,,,, clutch in good shape?
Devilin AblueDress!
New member
http://www.ngksparkplugs.com/docs/resistor_covers.pdf
Link to NGK spec page. I have used NGK with out issues. Pay attention to which cylinder. Cold/cooler pipe dead give away. This being a 98 (still has 98 non 3d ignition right?) Say for example its fouling PTO. 98 fires coils all at the same time, this will allow you to switch plug wires around. If fouling plug follows plug wire its electronic related. If PTO continues to foul its narrowed down to that carb/cylinder.
Link to NGK spec page. I have used NGK with out issues. Pay attention to which cylinder. Cold/cooler pipe dead give away. This being a 98 (still has 98 non 3d ignition right?) Say for example its fouling PTO. 98 fires coils all at the same time, this will allow you to switch plug wires around. If fouling plug follows plug wire its electronic related. If PTO continues to foul its narrowed down to that carb/cylinder.
Gerryjackman
New member
K ill test that out clutch has squeaked once in a while engage great seems to pull fine until I take it to the mountains but there is 6ft plus of snow there so I know it's hard on it but I think it should have more jam I'm not sure what kind of shape the clutch is in carbs were cleaned prob 800k ago should be fine how often do power valves cause issues could cleaning them help?
95rxl650
Member
As devil said, if all three are an even 110 then you should be ok although in the past, Ive had tired engines start popping plugs randomly.
Even at that, doing a ring job is cheap and can be done fairly quickly. Might wake er back up.
Check your choke plungers to be sure theyre closing completely.
You could also try the Iridium br9eix. Expensive plugs to be popping, but some guys swear theyve never fouled a plug since going to them.
Even at that, doing a ring job is cheap and can be done fairly quickly. Might wake er back up.
Check your choke plungers to be sure theyre closing completely.
You could also try the Iridium br9eix. Expensive plugs to be popping, but some guys swear theyve never fouled a plug since going to them.