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Author Topic: My Suzi T500 Project *New Video*  (Read 188174 times)

Offline johnu

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Re: My Suzi T500 Project (Finished Video & Pics!)
« Reply #1060 on: Feb 03, 2014, 18:19:52 »
First of all thanks as always for all the comments and suggestions, really appreciate it :)

To address the porting work first: Eric from sundial motorsports is well respected for his work tuning T500's, he has many years of doing this under his belt.  My requirement from Eric was that I would end up at around 55hp with all of the engine mods, I told him I wasn't too bothered about the bottom end but he insisted that he port it so that it would have good power all through the rev range.  This was corroborated by a member on here that did the calculations for my pipes, he told me that the porting specs on my cylinders is not real crazy.  The pipes were also not designed for power all in the high rpm range, they should work well at low rpm as well as up higher.

I raced two strokes for many years and I know the basics about how they run and how one thing will effect another but unfortunately I never really paid much attention to the carburation, I had a tuner that worked with me on that.  I guess what I am saying is that I can tell by feel that this is most likely not a porting issue but a jetting issue.

Anyway I will do a plug chop at full throttle to check where I'm at on the main jet.  My carbs are brand new and I have had them totally apart and there are no obvious issues.  All the jets I've used have been genuine Mikunis.

Again keep the comments coming I am glad there are people interested in this it is a big help!

Offline clem

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Re: My Suzi T500 Project (Finished Video & Pics!)
« Reply #1061 on: Feb 03, 2014, 23:07:44 »
John I wanted to give you props on the pipes. As I found out gas welding 22ga. is very tough!
"After every war there are soldiers who refuse to surrender. To this day there are still thousands who cling to their 30+ year old motorcycles, thinking that the war is still on, refusing to concede that the four-strokes have won"

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Offline Walms

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My Suzi T500 Project (Finished Video & Pics!)
« Reply #1062 on: Feb 04, 2014, 00:10:36 »
One sure fire way to know if you are running lean on the idle circuit is by wicking the throttle quickly in neutral, if you get any bog before it picks up, it's lean.

Offline johnu

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Re: My Suzi T500 Project (Finished Video & Pics!)
« Reply #1063 on: Feb 04, 2014, 00:52:36 »
John I wanted to give you props on the pipes. As I found out gas welding 22ga. is very tough!

Haha thanks, gas welding 22g mild steel is a piece of cake compared to gas welding aluminum tanks :)

Offline HollywoodMX

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Re: Re: My Suzi T500 Project (Finished Video & Pics!)
« Reply #1064 on: Feb 04, 2014, 03:51:51 »
First of all thanks as always for all the comments and suggestions, really appreciate it :)

To address the porting work first: Eric from sundial motorsports is well respected for his work tuning T500's, he has many years of doing this under his belt.  My requirement from Eric was that I would end up at around 55hp with all of the engine mods, I told him I wasn't too bothered about the bottom end but he insisted that he port it so that it would have good power all through the rev range.  This was corroborated by a member on here that did the calculations for my pipes, he told me that the porting specs on my cylinders is not real crazy.  The pipes were also not designed for power all in the high rpm range, they should work well at low rpm as well as up higher.

I raced two strokes for many years and I know the basics about how they run and how one thing will effect another but unfortunately I never really paid much attention to the carburation, I had a tuner that worked with me on that.  I guess what I am saying is that I can tell by feel that this is most likely not a porting issue but a jetting issue.

Anyway I will do a plug chop at full throttle to check where I'm at on the main jet.  My carbs are brand new and I have had them totally apart and there are no obvious issues.  All the jets I've used have been genuine Mikunis.

Again keep the comments coming I am glad there are people interested in this it is a big help!

Oh I was not saying it's a porting issue. I should have been more clear I was leaning that the porting is causing a jetting issue due to change in velocity of air coming through the carbs this compounds when you Ditch the factory air box for pods as well (some bikes worse than others).

The reason for the pop can top test is to increase your low volume low pressure at idle to a higher pressure.
Switching to focusing on the main might help in this drastic situation but if you are going to that, you might as well tune the needle in the same direction as the main. Meaning if leaning the main 1 size produces postive results I would lean the needle next and ping pong the two.

How much lower do the pilot sizes go? 25 sounds really small. What was stock again?
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Offline Walms

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My Suzi T500 Project (Finished Video & Pics!)
« Reply #1065 on: Feb 04, 2014, 06:08:49 »
The fella that ported your motor should be able to get you in the ball park with jetting unless you are using a carb he's not familiar with, ask him what slide, pilots, needle, needle jet and mains he uses.
I'm offering suggestions based on you saying the bike has no go off the line but then won't rev past 4k?

I like to start tuning with the idle circuit and work up. Who cares about the main, it doesn't effect idle but pilot and needle will bleed into the main. Get the bike sorted to 1/2 throttle then work on the mains.

Offline johnu

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Re: My Suzi T500 Project (Finished Video & Pics!)
« Reply #1066 on: Feb 04, 2014, 14:38:55 »
70 lbs less than my 500... ;)

Yup but you got one more cylinder ;D ;D ;D

Offline Walms

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My Suzi T500 Project (Finished Video & Pics!)
« Reply #1067 on: Feb 04, 2014, 17:17:59 »
Haha, you say that like its a bad thing! :)

Offline johnu

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Re: My Suzi T500 Project (Finished Video & Pics!)
« Reply #1068 on: Feb 05, 2014, 10:38:16 »
 ;)
Haha, you say that like its a bad thing! :)


It's bad when you have to buy 3 carbs instead of two ;) ;) ;)

Offline Walms

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My Suzi T500 Project (Finished Video & Pics!)
« Reply #1069 on: Feb 05, 2014, 10:39:55 »
How did you know I just blew $500 on carbs? :P