Hi to all, this is my first post, and it starts with a question. Just had my 07 96ci upgraded to the 103 ci stage 4. the bike goes well, but when I back off. there is no engine braking. the mods include new heads, auto decomp valves, 10.5:1 pistons, larger injectors & 58mm throttle body, 259E cams, new SE cam support plate and high flow oil pump. My understanding is that increasing compression from standard 9.3:1 to 10.5:1 would increase engine braking. Not sure if any over lap on cam timing would do this. I have had the acr's checked and they are ok returning 200psi compression. Does any one have any ideas. thanks

I'm having a guess here, but wouldn't an auto decompression cam / valves when idling, reduce the engine compression. e.g. rolling down a hill?

When its just sitting there at idle what is the engine rpm? If the idle rpm is set high then the motor will tend to "run on"when the throttle is closed from any speed giving you the impression of no engine braking

Hi Guy's, thanks for the feedback. The idle is perfect and it sound great. The problem is when riding at 100 klm in 6th, then changing down to 5th or even 4th, the bike just keeps rolling as if the clutch was pulled in, no engine braking. it would be the same feeling if you where driving a manual car and turned the ignition off, it just keeps rolling. My hunch is the new program is shutting the injectors off completely. I am hopping someone has had a similar problem and can shed some light.

Are you running a canned map ?
Try tweaking your Decel enleanment

My 103 10.1 comp bike does 225 in 4th gear flat at 6200 rpm. At 100 KPH in 6th my engine is laboring at 2200 RPM with a torquer tw5-6 cam. 5th gear is 2600 rpm at 100 k. The six speed box sucks with it high gearing so use the box and stop laboring your 10.5 engine.

I'm also running a larger rear pulley from 66 to 68 and looking at a smaller 31 drive pulley instead of the 32 

Sal called me about this last night (if this is the same bike) its a bit of a hard one without seeing/riding the bike but it maybe the idle controller staying open for some reason when riding???? Get the bike to Anthony for a propper tune and a look at.

Regards Andrew - T1

By	HogBag on 9/01/2013 8:02:12 PM
Subject:	RE: No engine braking with new 103ci stage 4 mods.
Message:	My 103 10.1 comp bike does 225 in 4th gear flat at 6200 rpm. At 100 KPH in 6th my engine is laboring at 2200 RPM with a torquer tw5-6 cam. 5th gear is 2600 rpm at 100 k. The six speed box sucks with it high gearing so use the box and stop laboring your 10.5 engine.

Who cares, were not talking about your bike.

Posted By HogBag on 9/01/2013 8:12:13 PM Subject: RE: No engine braking with new 103ci stage 4 mods. Message: I'm also running a larger rear pulley from 66 to 68 and looking at a smaller 31 drive pulley instead of the 32 How does this help the brother fix his problem?

Posted By	HSTC07 on 9/01/2013 7:17:10 PM
Subject:	RE: No engine braking with new 103ci stage 4 mods.
Message:	Hi Guy's, thanks for the feedback. The idle is perfect and it sound great. The problem is when riding at 100 klm in 6th, then changing down to 5th or even 4th, the bike just keeps rolling as if the clutch was pulled in, no engine braking. it would be the same feeling if you where driving a manual car and turned the ignition off, it just keeps rolling. My hunch is the new program is shutting the injectors off completely. I am hopping someone has had a similar problem and can shed some light

 

If the injectors are shutting down completely then the motor is still in gear with the clutch fully disengaged it would be running against compression and slowing.

Try riding at 100kph in say 3rd or 4th gear so the revs are a little higher roll the throttle off and pull the clutch in and glance at the tacho to see if the revs are still staying at the same as when the bike was in gear. My guess is that the revs are still up.

As terroristone mentioned, the idle air control (IAC) could be faulty, or need adjusting in the map that was installed with your stage 4 upgrade. Throttle position sensor (TPS) may be faulty, or need re-setting also. - Rob

Wifes nightster suffered from this prob. would also rev when stopped at lights. Idle air control was the prob. Dropped a new one in and no more issues.

Cheers Pete 

I think its normal,

Had exactly the same happen to me

My stock TC96 stage 1 had good engine braking.

Put SE204 cams in and lost most of the engine braking.

Now with a 103 stage 4 kit and still no engine braking. Maybe its the overlap of the cams.

Cranking compression was about the same as stock with the Se204"s and now 15psi higher with the stage 4.

Go figure,

Any update?

Hi guy's, again thanks to those who gave constructive advise, it was appreciated and followed up. It went back on the dyno, and with some tweaks to the program and change of slip ons, it improved and gained an extra 8 rwhp and increase in torque. Regards HSTC07

Yeah, not like before the mod's, but not far off. After riding for a couple of days, it feels normal, It's what you get used to. But in short it feels good again.

I might have sounded harsh but your cam works at higher RPM from 3000 up so when your plugging along in top gear at 2200 you won't have engine braking. If you drop a couple gears so your engine is working in the power band you will have more back pressure with the cam profile and also from the gearing. My 10.1 comp with the 5-6 woods cam starts making power from 1800 RPM so from low revs it has great back pressure when rolling back with the revs to slow down.