Banshee won't idle unless left choke is on

[252wheelieking]

Hi BHQ members, Im in need of advice for a little but big problem to me. What could be my problem?

 

Im concerned with my jetting here in NC at sea level with temp ranging from 25-45 degrees now.....I had 48 pilots, CEG needles-mid clip & 158 mains @ .5 turns out. It ran fine when the temp was from 40-70 degrees. I didn't notice the difference in power until after I burned my clutches completely out, then it overheated & blew the head gasket on the left cylinder. I figured it had a blow head gasket because the left cylinder kept dying after it got warm up. It will run fine until it got warm & I could smell the coolant. So I installed new clutch kit, new head gasket, 52 pilots,CEG needles mid clip & 170 mains @ .5 turns out.Symtoms are now the left cylinder doesn't die but it backfires or spit back, it starts right up & if you give it throttle it stall like it wants to cut off. You have to pat the throttle lightly to get the RPM's up. When the RPM's rise they hang at more than idling RPM level with choke off & will not return to idle. With choke on the left cylinder it idle perfect & throttle response is perfect. I'm lost....Thinking about just rebuilding the whole topend over with new gaskets. But thought I'll check with you ladys & gentlemen first. All help & advice is appreciated.

[hercalmighty]

Do a compression check and leak down test before you do anything else. It sounds like you might have some sort of problem with the left cylinder.

[252wheelieking]

Do a compression check and leak down test before you do anything else. It sounds like you might have some sort of problem with the left cylinder.

 

Thank You.... Im going to do a compression check first. I dont have a leak down tester. If the crank seals were leaking, do you think it will effect both cylinders. It seems like it would because the crank runs both sides & doesn't have a seal in between the bottomend. I don't know just curious. I think it might be my intake leaking cause it ran perfect before it overheated. The left cylinder doesn't die out like it did before since I installed the new head gasket.

Edited December 6, 2010 by 252wheelieking

[hercalmighty]

If a seal is going it will effect the side with the bad seal a lot more then the other. Its pretty simple and cheap to make a leak down tester. It is well worth the time and few bucks to make it.

[rdzbangshee]

i would rip the top end of the try some eel needles and some 6o pilots and 180 mains you could have a busted water pump gear and water on the pistons melts the rings and you can spry dow the engine with water and cover it in baking soda then stert it to find a air leak just clean it good firs with brake clean good luck bud.

[252wheelieking]

i would rip the top end of the try some eel needles and some 6o pilots and 180 mains you could have a busted water pump gear and water on the pistons melts the rings and you can spry dow the engine with water and cover it in baking soda then stert it to find a air leak just clean it good firs with brake clean good luck bud.

 

Thanks for the help BHQ fam. Im going to try all suggestions.

[252wheelieking]

i would rip the top end of the try some eel needles and some 6o pilots and 180 mains you could have a busted water pump gear and water on the pistons melts the rings and you can spry dow the engine with water and cover it in baking soda then stert it to find a air leak just clean it good firs with brake clean good luck bud.

 

@rdzbangshee....when I cover the engine with water & baking soda to find the exhaust leak, what should I be looking for if there is a leak? should it be bubbles from leaking compression or suction from the intakes or sumthin of that nature?

Edited December 8, 2010 by 252wheelieking

[crustydemon]

Why did you go from 158 to 170 mains if it ran fine before? That sounds way too big to me for a stock cylinder play port. The jets didnt blow your head gasket. I'd go 2 turns and work from there. Sync those carbs and make sure your choke nobs are both turned out the same amount. PJ's are a little tricky.

[crustydemon]

What is baking soda supposed to do?

[252wheelieking]

Why did you go from 158 to 170 mains if it ran fine before? That sounds way too big to me for a stock cylinder play port. The jets didnt blow your head gasket. I'd go 2 turns and work from there. Sync those carbs and make sure your choke nobs are both turned out the same amount. PJ's are a little tricky.

 

The 158 main was for the summer temperture ranging of 70-100 degrees. Now it ranging anywhere from 20-40 degrees & colder, so I play it safe to keep from having a melt down & install the 170.

 

I know the jets didn't blow my head gasket, the head gasket blew because my clutching were completely burn't out/slipping badly & I overheated the engine to the point it was steaming & all the coolant ran out the reservior.

 

I got the carbs sync'ed & both carb are out same number of turns with air & fuel screws @.5 turns out. & it still won't idle or have good throttle response unless I pull the choke up on the left carb.

 

Im going to do a leak down test & see if there are any leaks when I get the tools to build a leak down tester.

Thanks for your advice.

Edited December 9, 2010 by 252wheelieking

[252wheelieking]

What is baking soda supposed to do?

 

I was told to clean my engine good. Then spray my engine with water & cover it with baking soda. Start my engine & if it has any leaks it would suck up the baking soda.

[crustydemon]

Go ahead and do a leakdown but I would start with your screws out 1.5-2 turns out to see what happens. I never heard of using baking soda to check for leaks, I wouldnt do it.

[252wheelieking]

Go ahead and do a leakdown but I would start with your screws out 1.5-2 turns out to see what happens. I never heard of using baking soda to check for leaks, I wouldnt do it.

 

Thanks man.....I appreciate everbodys advice but im not going to do what everybody tells me either. I have a lil mechanical skills/common sense to know that if it sucks baking soda into my engine I will be creating another problem. No disrespect to anybody & like I said before I appreicate all advice. Im running with the compression test & then leak down test. Hopefully this finds the problem.

[252wheelieking]

Go ahead and do a leakdown but I would start with your screws out 1.5-2 turns out to see what happens. I never heard of using baking soda to check for leaks, I wouldnt do it.

 

I done a compression test on both cylinders & there both reading 90 psi. with the stock head. I don't think this cheap ass compression tester is acturate. I just got this top end rebuilt with less than 5 hrs. on it. The compression tester is one of them cheap ass $20 ones off ebay. The tip that im using is shorter than the actual spark plug. I used the stock head so I could break it in & it wouldn't cost alot in fuel to use pump 93.

 

If I use my coolhead with 18cc domes how much compression should I have @ sea level?

[hercalmighty]

http://www.nossmachine.com/banshee_heads.htm

 

Go to the bottom of the page and it has a chart for approximate compression for different domes and elevation