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Need help (starting point)


DAL

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I just advanced my timing 4 degrees, and immediately noticed the engine was running quite a bit hotter. I picked up a radiator cap temp gauge, which shows I'm running in the high 180's/low 190's at idle, which quickly increases to the low 200's after a quick pass or two (2-3 minutes). I checked my impeller (looks great), drained the coolant and added engine ice, which helped a little bit (about 5 degrees). I never actually measured the engine temp prior to advancing the timing, but would guess I was running in the 160's.

 

I did a carb rebuild soon after buying the Banshee with stock settings, air screw two turns out. She idles fine, but now when I blip the throttle, there is definitely some bogging in the first 1/4 throttle. When I turned the airscrew 1/2 turn back in (clockwise), it got rid of the bog, but caused my idle temp to quickly hit 215 before I shut her off.

 

I would like to dial my carbs in before addressing additional cooling issues like a cool head and new impeller. I just need a starting point suggestion (mains, pilots, needle position, etc), and can tweak from there.

 

Here are my engine mods:

 

Bored .020 over

Pro Circuit pipes

Airbox lid w/holes and K&N filter

+4 timing

Premix 32:1

 

Thanks guys.

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With those mods at my elevation without porting you would be at 270-280 main and stock pilot.

 

Yeah, I guess I should have mentioned I'm at sea level.

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Awesome. Do you guys suggest buying a full kit (includes mains/pilots), or just buying the parts individually?

 

Any brands you recommend for either? What's the difference between stage 1, 2, and 3 kits?

Edited by DAL
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Awesome. Do you guys suggest buying a full kit (includes mains/pilots), or just buying the parts individually?

 

Any brands you recommend for either? What's the difference between stage 1, 2, and 3 kits?

i baught a jet kit that came with jets from 260-340 for 25 dollars

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a gas bike after a few runs was no way ever running 160 degree's. your probably freaking out over nothing gas motors will run up to 230degree's escpecially pump motors. you just have to let them cool off. making power has this trade off of making heat also sucks when that happens.

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a gas bike after a few runs was no way ever running 160 degree's. your probably freaking out over nothing gas motors will run up to 230degree's escpecially pump motors. you just have to let them cool off. making power has this trade off of making heat also sucks when that happens.

 

Could be. I understand power = heat, but she's running way too hot, way too quickly (whatever the original temp may have been). If I don't shut her down after less than 5 minutes, she'd run well over 230.

 

After searching around, I came across Vito's jets - are these good quality? Any other recommendations?

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does it get that hot from just sitting and idleing or are you riding it around? does the water pump seem to move water through the radiator? if you take the cap off COLD then start it does the fluid go wossh in there or just vibrate from teh motor running.. is the rad clean and not all bent up? they dont have a cooling fan so if its just sitting in the gerage idleing while yoru staring at the temp gage. its going to get hot.

 

it may also have a head gasket failure but usually you can tell if it does pretty quick...

 

if all else fails back the timing back off and see if it cools down if that the only thing you did you may have some compression issue's or you need to consider running straight 110.

 

on the jets you can just get mikuni OEM jets they are called short hex, any site sponsor that sells parts should be able to get you what you need or even any local shop worth a darn will have mikuni hex mains in stock the slows you might have to order. if you go to a shop adn say you want banshee main jets and they start typing in the computer ask them what they are dooing. if they are looking them up with the OEM yamaha parts locater slap them and ask for the parts unlimited ATV book, go to FUEL AIR section and look for the jets or use the back and look up mikuni jets.

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does it get that hot from just sitting and idleing or are you riding it around? does the water pump seem to move water through the radiator? if you take the cap off COLD then start it does the fluid go wossh in there or just vibrate from teh motor running.. is the rad clean and not all bent up? they dont have a cooling fan so if its just sitting in the gerage idleing while yoru staring at the temp gage. its going to get hot.

 

it may also have a head gasket failure but usually you can tell if it does pretty quick...

 

if all else fails back the timing back off and see if it cools down if that the only thing you did you may have some compression issue's or you need to consider running straight 110.

 

on the jets you can just get mikuni OEM jets they are called short hex, any site sponsor that sells parts should be able to get you what you need or even any local shop worth a darn will have mikuni hex mains in stock the slows you might have to order. if you go to a shop adn say you want banshee main jets and they start typing in the computer ask them what they are dooing. if they are looking them up with the OEM yamaha parts locater slap them and ask for the parts unlimited ATV book, go to FUEL AIR section and look for the jets or use the back and look up mikuni jets.

 

Awesome - thanks for the tips. I'll start with the jetting, and work my way around if that doesn't solve the issue.

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  • 3 weeks later...

OK...so I bumped up to a 27.5 pilot and a 290 main, but the bog off idle seems like it's gotten worse. As mentioned in the first post, if I turn the airscrew in it seems to help a bit. I'm new to jetting, but it seems odd if the low-rpm bogging was initially caused by running too lean, but got worse after I go up a size.

 

Am I still running too lean? Do I need to go up to a 30 pilot?

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I got almost the same problem going on after I installed timing plate cool head vf3 took out this weekend and she blew water outta the radiator ... I also just did a vito water impeller and are running engine ice and over sized radiator .. and mine still getting hot not sure I think its the timming plate doing it

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I got almost the same problem going on after I installed timing plate cool head vf3 took out this weekend and she blew water outta the radiator ... I also just did a vito water impeller and are running engine ice and over sized radiator .. and mine still getting hot not sure I think its the timming plate doing it

 

I ran her for about 15 minutes this weekend, and bumping up the jetting appeared to have basically cured the overheating, it's just the low end bog that's persisting. I have three larger sized pilots on their way right now, which I'm fairly confident will cure the bogging. Will be sure to report back.

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