Stumped!

[Dr Honda]

I am saying after taking carbs off this most recent time to delve into the issue at hand with ski operation. Before disassembling diaphragms and all that to pump the carb up and see if it holds psi, or bleeds down to either verify this is the problem with ski, or rule it out. Happened on my ski where everything passed with diaphragm cover/plate not installed, but once installed it was touching diaphragm ever so slightly which pushed needle and seat lever arm and caused it to bleed down.

Rob

OK... that's what I was kind of thinking.

 

[PGHMAN]

I plan to test later today with the diaphragm and cover on. I was just curious last night to verify the jets numbers being the carbs weren't original.
In regards to the plugs, now that I think about it maybe unburnt oil. I did not do touch to a towel but smelled and did they not smell like gas.
N/S lever is flush. Premix 40 to 1. Injector arm on correctly and aligned.
Should I proceed purchasing the 130 main? Any thought where to purchase?

 

[Dr Honda]

...................N/S lever is flush. Premix 40 to 1. Injector arm on correctly and aligned.
Should I proceed purchasing the 130 main? Any thought where to purchase?

40:1 !! Wow... that's a lot, with the injector. But... I guess it's OK on a fresh engine. Probably Smokey.

Yes... install 130 mains, and then open the high speed needle an 1/8th to 1/4 turn at first, and close as needed. (as it breaks in) What people don't realize... when you go bigger on the cyl size... each pulse pulls in more air. In turn... it draws more fuel too... and sometimes... you actually jet smaller. SO that... along with bigger jets could be causing your issues.



One last thought......


since you have a bunch of extra oil... after you get re-jetted... if you are still having fouling issues... go up one heat range on the plugs. That should help them burn clean.

 

[PGHMAN]

If I remember I used 24-28 oz in the 9 gallon tank. Very smokey...wife complained each time I started on the hose. I have gone through 2/3 of the premix tank and recently topped off with fresh gas.
I ordered the 130 and will take your advise and open at first.
Thanks to everyone for your guidance! I'll report back once I receive the new seats and install.

 

[PGHMAN]

I received the 130 jets yesterday and plan to install today after work and will perform the necessary tests. Question, should I maintain the high/low settings zero high, low 1 3/4 with the new jet?
I just reread the above post and saw [MENTION=16022]Dr Honda[/MENTION] comment regarding the 1/8-1/4 out on the high.

 

[Dr Honda]

Low should stay the same. Open the high about 1/8th turn, and see how that feels. (may still be too rich)

 

[suke]

I received the 130 jets yesterday and plan to install today after work and will perform the necessary tests. Question, should I maintain the high/low settings zero high, low 1 3/4 with the new jet?
I just reread the above post and saw [MENTION=16022]Dr Honda[/MENTION] comment regarding the 1/8-1/4 out on the high.

I turned my highs out 1/8-1/4 since it was still lean on the MAG carb when doing plug chops. Dead perfect for low speed. Nice and tan!!!

 

[PGHMAN]

I turned my highs out 1/8-1/4 since it was still lean on the MAG carb when doing plug chops. Dead perfect for low speed. Nice and tan!!!

Glad to hear that you got the XP running well. I had the GTX out Sunday.....what nice day on Jordan. Plan to finish up the XP carb install tomorrow evening with hopes to get out this weekend to see how it runs.
I am somewhat bummed that I sold the 97 SPX that I picked early summer. Got it from a older gent in Cary - it was clean and was all original with 150 on each hole. Picked up cheap for the trailer but later decided to the pair and made some cash. [MENTION=57920]racerxxx[/MENTION] stated to keep it and unload the XP 720. Oh well.

 

[suke]

I plan to get out Sat and I know 1983 was planning too as well. Just need to helicoil my rv cover and put it back together.....again. hopefully for the last time. Just need to find out what kit to get to fix it. Seems the local carquest has all the kits in stock.

 

[PGHMAN]

I am hoping to get out early Saturday depending on how the youngest feels.....she's having her wisdom teeth extracted tomorrow and wife has to work Saturday so I may have to play nurse.

 

[suke]

As long as I get my ski back together I can be out there anytime. Rob will likely come out later in the day I'd imagine. I got the helicoil stuff this morning so plan to do that when I get home this evening once we get the baby to bed.

 

[PGHMAN]

Stumped again! Got the new 130 mains and installed, settings H 1/8 out, L 1 3/4, and took it out yesterday. Other than a slight hesitation on the low end it ran well for 35-45 minutes total with breaks in between. After the last break of about 20 minutes it starts, idles then dies with any throttle....called it a day. Below are the plugs which were new. One on the left is the mag plug. Thoughts?

 

[Dr Honda]

They look ok to me. But the MAG plug is oily. I wonder if you have a leak on the crank?

Let me think about this one, and re-read the posts.

 

[PGHMAN]

Did the leak down on the engine during rebuild which included a new rebuilt crank. Also, retested the pop off - 42, and did the leak test as [MENTION=72134]1983[/MENTION] stated after installing the diaphragm and cover, held 10 psi for ten minutes.
Thinking about pulling the head cover tonight to get a little deeper on this.

 

[Dr Honda]

Do you have a bore scope? If you do, take pictures of the piston crowns for me. If not, as you were saying... pop the head off, and take a picture. I want to see the "Wash" pattern.

 

[PGHMAN]

Do you have a bore scope? If you do, take pictures of the piston crowns for me. If not, as you were saying... pop the head off, and take a picture. I want to see the "Wash" pattern.

Negative on the bore scope but will take pics of the piston crowns and forward.

 

[PGHMAN]

Pulled the cylinder head and cover.






The motor has maybe 2.5 hours on it. Any thoughts based on the above pics? Thanks guys.

 

[PGHMAN]

Curious why I there's no carbon build up on the cylinder dome and only the piston crowns? Also, when I had it out Sunday I felt the cylinders and each were very hot could barely keep my hand on for just second.....I have checked the passages and I have water coming out the pee hole. This is getting the best of me

 

[Dr Honda]

Curious why I there's no carbon build up on the cylinder dome and only the piston crowns? .................

That's because it's crazy rich still. OR... you are getting water in the engine some how.


Basically... you will build carbon at you burn the fuel an oil... right??

OK, as you get "Wet/Cool" fuel in the top half of the engine, you will clean the piston crown. This cleaning process will show up by the port. The pattern it produces is known as "Piston Wash". It's a better way of reading how an engine is running, over just looking at plugs. But, in practice... it takes a bore scope, since you don't want to take an engine apart at the lake while tuning.



OK.... well...................... Ummmmm................................




Something is still up with your carbs. If you want to send them to me... PM me for an address. With my new job, I'm traveling... but I should be home for the next couple weeks.

 

[PGHMAN]

Thanks Tony....I'll PM for address. I am considering pulling the motor and redo the leak test. Also, I had replaced the armature plate and pretty certain I aligned the marks. Maybe an ignition timing issue?

 

[68ragtop]

curious, have you run this machine at WOT for any length of time. The carbon doesn't build up crazy fast, I think we were expecting to see pistons that had maybe 10-15% wash & just in front of the ports. Do your plugs look like that (black & wet) after a 30 second WOT & chop? Those pistons are really cleaned off.

 

[PGHMAN]

Have yet to go WOT - been cautious during the break in. To add, my wife rode it last this weekend and she just scoots around lake even though I tell her fluctuate the throttle. Come to think of it she was the last to ride it two weeks ago as well.
Have not done the plug chop test.

 

[PGHMAN]

curious, have you run this machine at WOT for any length of time. The carbon doesn't build up crazy fast, I think we were expecting to see pistons that had maybe 10-15% wash & just in front of the ports. Do your plugs look like that (black & wet) after a 30 second WOT & chop? Those pistons are really cleaned off.

Hey 68 - are you stating the piston crowns have too much or to little wash based on the little time on the engine?

 

[PGHMAN]

Okay, I pulled the motor to recheck and redo a leak test. I can't get a top end reading (compression at 145 per hole) to the gauge but if I hold my finger over the exhaust manifold fitting (low end) I feel the pressure. Same is true with low end test... I am Stumped again! Any suggestions appreciated.

 

[Dr Honda]

To do a leak test... you have to bolt on covers over the manifolds. Did you do that?