xander450 Posted April 3, 2012 Report Share Posted April 3, 2012 So I've been building a TZ350 replica around a banshee motor - just finished putting it together for a test run, and no start. Advice? Here's what I know: - compression's 105 on one side and 120 on the other. The motor's got a decked head and, according to the guy I bought it from, should run on 100 octane; but clearly compression is lower than it ought to be (500ft above sea level). - Spark seems good - Fuel is definitely flowing. Just to be sure, I kicked a bit of starting fluid through the carbs and tried starting - no change. - Using Motul 800 at 50:1 and VIP 110 race gas So obviously the 110 is unnecessary at the compression I'm at - didn't have a comp tester, borrowed one after it wouldn't start. Would a lower compression motor have trouble starting on 110? If 105 psi is low for stock, and it's got a decked head which ought to take it up to 150+, would it not run at 105/120? Even bump starting it down a hill was unsuccessful. Other ideas? Let's suppose the motor's in need of a rebuild. I've got everything I need to put together a serval motor, but can't find a local builder. Know someone in Austin or the surrounding area that can put a solid motor together? Quote Link to comment Share on other sites More sharing options...
ClayAiken Posted April 3, 2012 Report Share Posted April 3, 2012 Do u haz a Spark? That would be my first guess and 120/105 definitely is in need of a rebuild but it should at least start on it. Quote Link to comment Share on other sites More sharing options...
xander450 Posted April 3, 2012 Author Report Share Posted April 3, 2012 Yeah, have spark, looks great. Quote Link to comment Share on other sites More sharing options...
slothman Posted April 3, 2012 Report Share Posted April 3, 2012 So I've been building a TZ350 replica around a banshee motor - just finished putting it together for a test run, and no start. Advice? Here's what I know: - compression's 105 on one side and 120 on the other. The motor's got a decked head and, according to the guy I bought it from, should run on 100 octane; but clearly compression is lower than it ought to be (500ft above sea level). - Spark seems good - Fuel is definitely flowing. Just to be sure, I kicked a bit of starting fluid through the carbs and tried starting - no change. - Using Motul 800 at 50:1 and VIP 110 race gas So obviously the 110 is unnecessary at the compression I'm at - didn't have a comp tester, borrowed one after it wouldn't start. Would a lower compression motor have trouble starting on 110? If 105 psi is low for stock, and it's got a decked head which ought to take it up to 150+, would it not run at 105/120? Even bump starting it down a hill was unsuccessful. Other ideas? Let's suppose the motor's in need of a rebuild. I've got everything I need to put together a serval motor, but can't find a local builder. Know someone in Austin or the surrounding area that can put a solid motor together? 105 should be enough to start the engine. I would take apart the carbs and make sure everything is clean, especially the pilot jets Quote Link to comment Share on other sites More sharing options...
xander450 Posted April 3, 2012 Author Report Share Posted April 3, 2012 105 should be enough to start the engine. I would take apart the carbs and make sure everything is clean, especially the pilot jets One of the things that makes this complicated is that I don't even know where to begin with the jetting. Trinity stage 2 motor, VM32 carbs... how's 35 sound for the pilots? Quote Link to comment Share on other sites More sharing options...
slothman Posted April 3, 2012 Report Share Posted April 3, 2012 One of the things that makes this complicated is that I don't even know where to begin with the jetting. Trinity stage 2 motor, VM32 carbs... how's 35 sound for the pilots? not sure about the 32s, might wanna take a look in the jetting section. Another crazy idea- make sure the petcock is working ! After my engine rebuild my bike wouldn't start....then I found out the "ON" switch was clogged (the reserve worked) Quote Link to comment Share on other sites More sharing options...
zach45 Posted April 3, 2012 Report Share Posted April 3, 2012 32? Start with stock sized pilots Quote Link to comment Share on other sites More sharing options...
zach45 Posted April 3, 2012 Report Share Posted April 3, 2012 32? Start with stock sized pilots maybe even 27.5 Quote Link to comment Share on other sites More sharing options...
ticktock Posted April 4, 2012 Report Share Posted April 4, 2012 I would check the flywheel key. Just because you have a spark it might have a missing key and not firing at the correct time. Pick up gap @ .020. Pilots might be big but it should pop off. Do a leak down test. Check the reeds make sure they are good. 100lbs is enough to start on gas. I have seen them run strong at 90. If it still won't start you are going to have to take it apart and check everything. Build that serval yourself!! Call Jeff at fast and talk to him. He will get you straight Adam Quote Link to comment Share on other sites More sharing options...
xander450 Posted April 4, 2012 Author Report Share Posted April 4, 2012 Holy hell... 25 pilots did it, thanks so much for the advice!! This has been 16 months in the making... can't express my excitement at hearing it run this evening. Ok, so mains.... I looked through the jetting threads and couldn't find anything resembling my setup. Trinity stage 2 motor, 32mm VMs... ideas on where to start the jetting process on the mains? As for building the serval myself - yeah, that's probably what happens now. I was hoping to find a builder because I figured they'd do it faster than I would as this would be my first 2 stroke motor build, but if I've got a running motor in the machine now I can handle doing it slowly. Thanks again, Alex Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted April 4, 2012 Report Share Posted April 4, 2012 Holy hell... 25 pilots did it, thanks so much for the advice!! This has been 16 months in the making... can't express my excitement at hearing it run this evening. Ok, so mains.... I looked through the jetting threads and couldn't find anything resembling my setup. Trinity stage 2 motor, 32mm VMs... ideas on where to start the jetting process on the mains? As for building the serval myself - yeah, that's probably what happens now. I was hoping to find a builder because I figured they'd do it faster than I would as this would be my first 2 stroke motor build, but if I've got a running motor in the machine now I can handle doing it slowly. Thanks again, Alex I'd probably start with a 300 main and work from there. Your pilot could actually be a 27.5 too as 25 is the stock pilot size. Try the 300 main and do some wide open throttle plug checks and see how they look. Quote Link to comment Share on other sites More sharing options...
Starwriter Posted April 4, 2012 Report Share Posted April 4, 2012 I agree that 300 main is a good place to start. However, don't be surprised if it is pig fat, slobbery rich. I can tell you from experience that it takes a lot more fuel to run paddles across the sand than the same motor in a street bike with very little rolling resistance. Starting out rich and leaning it down is a lot safer than being too lean, enjoying the ride and having your wallet feel the agony of defeat as your right piston gets a 3rd window. I wouldn't be surprised if your final jetting ends up in the 250 to 270 range. Quote Link to comment Share on other sites More sharing options...
dave5.0 Posted April 5, 2012 Report Share Posted April 5, 2012 So I've been building a TZ350 replica around a banshee motor Pics? You say replica, so what did it used to be? Kit, another bike? Quote Link to comment Share on other sites More sharing options...
xander450 Posted April 5, 2012 Author Report Share Posted April 5, 2012 Pics? You say replica, so what did it used to be? Kit, another bike? TZ bodywork, banshee motor, RD frame (so I can register and ride on the street), and a long list of other things. Happy to give you more details if you're interested. Here's a pic from about a month ago... a few things are missing, but mostly there. Quote Link to comment Share on other sites More sharing options...
SAVAGE420 Posted April 5, 2012 Report Share Posted April 5, 2012 Subscribed! That is a bad ass wicked bike man. Quote Link to comment Share on other sites More sharing options...
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