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Old 09-01-2008, 08:41 AM   #316
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For those who must know about timing: Taken from TDC.

Rotor open 223 deg
Rotor close 59 deg
Rotor duration 196 deg
Exhaust duration 171 deg
Boost duration 122 deg
Transfer duration 125 deg

Compression ratio I found to be low at 8.9:1. This is good for making the engine consistent and easier to tune. However, a higher ratio will give slightly more power. Careful not to run too lean or you will get detonation. Keep it on the rich side of the needle with higher compression ratios and you will have a very strong engine running cool. Maybe that's why I broke a crank. lol!
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Old 09-06-2008, 08:49 AM   #317
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Ok guys, I have just finished breaking in my JL Tuned eng on a bench (4 x 125cc tank) Took it out to the track today for a test. I never have to touch the HSN as the tune was spot on with max temp 130C (266F) using 25% tornado and Sirio 2611 pipe (I still haven't got 2607 pipe yet), however I just needed to lower the idle stop needle a bit and lean out Idle mix needle as the eng took a while to get back to idle after full throttle. After that everything went well, torque was more than enough as well as its top speed.

There are 2 things i m worried right now, first , upon inspection I found some oil coming from the ball end linkage of the carb , I guess its from the barrel gasket, will this be a potential problem tuning wise (leaking)?

Second, I found the crankshaft has too much play, like when you move it up,down, left, right. Even when the clutch assembly is fully assemble. From my past experience, i guess this is from bearing tolerance. My personal liking is to have a very tight, wobble free crankshaft, so that I m sure the crankshaft is spinning true. I wonder if I can change the inner bearing with OS TZ's one as it is the same size and has a very tight tolerance.

Anyhow I m very happy with the performance of this engine and I think I m going to get the non tuned JL and the 2607 pipe too very soon.
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Old 09-07-2008, 02:38 AM   #318
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Originally Posted by dameetz View Post
Ok guys, I have just finished breaking in my JL Tuned eng on a bench (4 x 125cc tank) Took it out to the track today for a test. I never have to touch the HSN as the tune was spot on with max temp 130C (266F) using 25% tornado and Sirio 2611 pipe (I still haven't got 2607 pipe yet), however I just needed to lower the idle stop needle a bit and lean out Idle mix needle as the eng took a while to get back to idle after full throttle. After that everything went well, torque was more than enough as well as its top speed.

There are 2 things i m worried right now, first , upon inspection I found some oil coming from the ball end linkage of the carb , I guess its from the barrel gasket, will this be a potential problem tuning wise (leaking)?

Second, I found the crankshaft has too much play, like when you move it up,down, left, right. Even when the clutch assembly is fully assemble. From my past experience, i guess this is from bearing tolerance. My personal liking is to have a very tight, wobble free crankshaft, so that I m sure the crankshaft is spinning true. I wonder if I can change the inner bearing with OS TZ's one as it is the same size and has a very tight tolerance.

Anyhow I m very happy with the performance of this engine and I think I m going to get the non tuned JL and the 2607 pipe too very soon.
Hi I just change my bearing as the inner bearing just had to much play and kept on stripping first gear spurs, I sourced my bearings very cheaply from walawala store on ebay.
goodluck!
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Old 09-07-2008, 05:53 AM   #319
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aussies1129, did u replace the inner one only or both inner and outer bearings? How do find the play after changing the bearing, is it still there, reduce or completely gone?

Thanks.
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Old 09-07-2008, 06:11 AM   #320
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aussies1129, did u replace the inner one only or both inner and outer bearings? How do find the play after changing the bearing, is it still there, reduce or completely gone?

Thanks.
Hi the play was due to the inner bearing but I replaced both inner and outer and that then solved the problem. Its best to just change the two as the extra cost for the outer was minimal.
cheers
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Old 10-26-2008, 08:27 AM   #321
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I just stripped my engine down for a clean and noticed it now can be turned 306deg on the fly wheel so there no pinch or very little at tdc so what now straight for the trash and buy another???
cheers
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Old 10-26-2008, 12:48 PM   #322
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Originally Posted by aussies1129 View Post
I just stripped my engine down for a clean and noticed it now can be turned 306deg on the fly wheel so there no pinch or very little at tdc so what now straight for the trash and buy another???
cheers
Donít confuse compression with pinch; Sleeve Pinch is not that important contrary to popular belief. The question is how well it seals as soon as the piston starts to close the exhaust port and if it holds compression after you roll it to top dead center.
Place a few drops of after run oil trough the top (removing plug), then place plug in place, then roll piston to top dead center and listen and look for air bubbles through exhaust port. If thereís none, then your engine still has compression, even if it has no pinch.
The fastest motors I use, have zero pinch.

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Old 10-26-2008, 01:30 PM   #323
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Don't trash it until it either noticeably loses power or won't idle and hold a tune anymore. A low pinch motor with good compression is a fast motor.
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Old 10-26-2008, 02:54 PM   #324
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Originally Posted by afm View Post
Donít confuse compression with pinch; Sleeve Pinch is not that important contrary to popular belief. The question is how well it seals as soon as the piston starts to close the exhaust port and if it holds compression after you roll it to top dead center.
Place a few drops of after run oil trough the top (removing plug), then place plug in place, then roll piston to top dead center and listen and look for air bubbles through exhaust port. If thereís none, then your engine still has compression, even if it has no pinch.
The fastest motors I use, have zero pinch.

AFM
cheers guys it was running well even to the end of my last run, I will look at it closer as it really hasnt had alot of fuel through it hopefully it should be all good. does anyone else running this engine notice that after a few runs there is a small bit of crankshaft wobble??
thanks
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Old 10-26-2008, 06:22 PM   #325
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guys what are you doing with the picco manifold to fit good in the car?
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Old 10-26-2008, 07:06 PM   #326
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guys what are you doing with the picco manifold to fit good in the car?
yeah my 2607 manifold sticks out a bit but fits in the body ok?
cheers
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Old 10-27-2008, 01:22 PM   #327
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............... does anyone else running this engine notice that after a few runs there is a small bit of crankshaft wobble??
thanks
Yes, I think it is the weakest point on this engines, bearings have a lot of tolerance after a few runs, specially the inside bearing. Change inside bearing with the one from OS TZ, and wobble problmes should go.

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Old 10-27-2008, 11:53 PM   #328
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Quote:
Originally Posted by aussies1129 View Post
I just stripped my engine down for a clean and noticed it now can be turned 306deg on the fly wheel so there no pinch or very little at tdc so what now straight for the trash and buy another???
cheers
When you throw it away, throw it my way. That's when they are usually best
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Old 11-03-2008, 10:56 AM   #329
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Default Tuning Help

I am running with the 2607 pipe with Maxy 25% but unable to get the right tune. Down the straight its fast but when coming out of corners it seems to bog slightlightly but does not cut off and I am able to run a full tank with ease. Performance lacks

When I richen up the bottom end as recommended for Piccos the engine is hard to start at cuts off when the ignitor is removed.

Any suggestions guys(I have already changed fuel and plug)
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Old 11-03-2008, 11:49 AM   #330
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Originally Posted by jelayne View Post
I am running with the 2607 pipe with Maxy 25% but unable to get the right tune. Down the straight its fast but when coming out of corners it seems to bog slightlightly but does not cut off and I am able to run a full tank with ease. Performance lacks

When I richen up the bottom end as recommended for Piccos the engine is hard to start at cuts off when the ignitor is removed.

Any suggestions guys(I have already changed fuel and plug)
Jevaughn,
How is your clutch setting? I am not saying that it is wrong, as you know that if a clutch setting is too heavy then it will cause the engine to bog as it is not letting the engine rev up a little bit before engaging, meaning your clutch needs to slip a little bit before fully engaging, and your endplay needs to be at a minimum of 0.5mm, measured without the inner bearing installed.
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