Mr. Knowsalot I have a 2001 Raptor. IT is Piped, Jetted, ported-polished, Cam, K&N, Nology Spark Wire and 11:1 comp. Here's my Problem. I just had it rejetted about a month and a half ago. They Jetted it to the Sniffer on the Dyno, it is dead nuts on. I've been running Race fuel 114 octane B35. About 3 months ago I had a new head put on. They said that the fuel was too dry. So I have been mixing it down half and half with 92. They said if I had let my Machine sit for about three months I would have bent every rod in it trying to turn it over. Well now it seems to be running hot, my pipes are glowing when it is at idle. Not real red just enough if you look hard you can tell. My silencer is even too hot to touch. The shop said to put a Table spoon of 2 stroke oil in the gas tank when it is full to lube everything up. This was before I noticed it was hot. What have I done?
If you could help me out, I would appreciate it. Thanks KnowsAlot and all the other Tech Guru's [img]i/expressions/face-icon-small-smile.gif[/img]

 

I don't see what 1 tablespoon of 2 stroke oil would do. If mixed with a full tank which is 3+ gallons, that's like a 300:1 ratio, which I don't see as being enough to do anything. You mention getting it jetted on the dyno a month and a half ago, yet you also mention problems from 3 months ago. Any problem prior to the dyno tunning should have been corrected. When it was dyno tunned, was it with straight race gas, or with the 50/50 mix with 92? If the guys that dyno tunned it know what they are doing and you haven't changed anything with the setup (like changing your gas), you really shouldn't have any problems. Also, the comment about letting it sit for 3 months and then bending every rod when you try to start it is confusing. First, there is only one rod in a single cylinder engine and 2nd, I've only seen rods bend from failure at high RPM and high load conditions or in race cars with mechanical fuel injection. When they spin and the engine stalls, the mechanical fuel injection keeps pumping enough fuel in to fill the cylinder up enough so that before you hit top dead center, the combustion chamber is full of fuel to the point that the piston can not go any further and that causes the rod to bend. I don't see either of those situations happening at startup.

 

I think what the problem is is that you are not running ful race gas anymore so now your motor is lean. You can usually run a leaner mixture with race gas. Jet it up some with this mixture and it should run fine.

 

Did they use the sniffer at idle?

 

Zombie, I think it's time for you to talk to a new shop. It sounds like they are giveing you some "snake oil" advice.

You comments about 1 month and 3 months is confusing - maybe you can clarify for us.

11:1 isn't that high of compression but depending on your cam profile it's possible that you need race gas??? I agree that it is likely that you are running lean you should bump it up a notch or 2 and see how it runs and how your exhaust temp reacts. Other Raptor owners could advise you better on your set-up vs race gas usage.

Putting oil in your gas makes absolutely no sense. Find another shop.

What the heck is fuel that is "too dry"??? Find another shop.

Letting it sit will not cause you to bend a rod. If for some reson your cylinder was silled with 2 stroke oil or "dry fuel" then maybe that would casue a problem but that isn't going to happen in any normal situation.

 

Lets start by the fuel your using is a little over kill. 110 fuel is good for the most part up to 14:1 compression. So do as you will, but this will help. I also suggest mixxing 50/50 untill you have to use straight race fuel.
The 2 stroke oil in the gas is a common practice of using AV or any other type dry fuel in a four stroke engine, but a dangerous way to live. Weather you need race fuel or not is depending on the piston top to head relationship, not always the compression ratio. Thier are many stock machines that use 11:1 or higher that run just fine on pump gas.

I would start by doing a leak down test. Go to the hardware store buy some fittings to install a manifold in your spark plug hole. At TDC of the compression stroke put 7 psi's of air in the cylinder and make sure it holds it for 10 minutes. This will stop any maybe head gasket or valve seat questions.

I have done this kit as well but my statement is pretty much for all of them. When raising the compression you slow volocity thru the carb, hense jetting usually goes down. I run tight piston to wall clearences and use long braek in periods for longevity reasons. If I remember rite the raptor 11:1 piston calls for a .002" clearence.

What I found the way I do it is after a couple months or so the rings seat all the parts start working well and jetting starts to lean out due to the volocity thru the carb becomes graeter. This is just a trend I've found happining for many years on many machines.

Most poeple who send thier engines off under more of a mass produced engine building arena get larger piston to wall clearences and don't seem to experience these problems.

As far as jetting on a dyno and thinking thats the best, well thats just a little beyound me and realy haven't had that work for me yet.

So pick your fuel and start jetting, you will find that you can't just walk out and hit it spot on in one day. Use a couple ride times between jet changes so you know whats realy going on, but start fat and work your way down.

Just changing jets and running 300' drags is ok, but you will find that over time and the way you realy ride will get you more prosise jetting than a 300' drag will.

 

Thanks Guys I appreciate the Info. Sorry if I was vague it was late. I'm going to try to rejet. The Temp has risen 30 degrees since I jetted last.
An the humidity is terrible here. I called the shop they said to turn my Air/Fuel ratio screws out to run alil richer. Once again thanks to all who replied CBUS660r, Mtecate4G, Garcy660, WyoDuner and Gaff. I will let you know what I find was wrong. Cause I know WyoDuner doesen't like it when you don't let him know what the problem was. [img]i/expressions/face-icon-small-smile.gif[/img] LOL

 

Zombie- what pilot jets you running?? My 11-1 Trinity 686 is HAPPY and MEAN on 93 octane. It was GRUMPY on 107 race fuel. I am running the factory pilots and i am a little lean on the bottom. I never stay there long.

 

Zombie- where did you get the nology wire? I want to order one myself. Thanks

 

My Jets are 185 and 190 mains. I got the Wire from NOLOGY