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Matthew · 04-03-2004, 07:52 PM

I have a well worn TT70 and was wondering if it is time to rebuild it. I almost have to screw the low end needle all the way out (at least it seems that way) to get it to idle. It has compression but not as much as i think it should. Any help?

Al Magaloff · 04-04-2004, 06:59 AM

I think you will find that, the parts to rebuild will cost more than a new unit.

WillJames · 04-04-2004, 08:26 AM

That is what I was gogin to Say Al.

When you do replace it get a 91. That R60 is a fairly heavy (bricklike actually). I was VERY happy when I went from a YS-80 to the 91 C-SPEC in both my Raptors.

You are already running 690's on it so your R60 would be a ROCKET with the 91.

Matthew · 04-04-2004, 09:04 AM

I'd love to drop a 90 in the pup but I don't think I'm ready for the power it holds. It still seems to scream with the 70 in it and were my flying is now I think the 90 would make it to fast for me. Any thoughts?

Al Magaloff · 04-04-2004, 09:10 AM

I think the YS80 is a great compromise. No gear changes, same blade/boom. And just because your car will do 120mph, doesn't mean you need to go there all the time!

I'm not a real fan of the TT70 or TT90. The OS 70 would be a decent choice for replacement too, but I've never seen a motor more plagued, than that thing.

Matthew · 04-04-2004, 09:44 AM

Your right as fare as the driving goes. I never thought of it that way. I'd need to change the gearing, muffler, and Metal fan with the 80? Any thing else that would have to change?

DavidH · 04-04-2004, 09:54 AM

Matthew,
The YS 80 would need to be geared down in the mid to low 8 range.
It will run in the 9 range, but it is basically just burning lots of fuel and not supplying much power. Also in the 9 range you will need to keep a closer eye on the rpms to not overspeed the motor.
For the YS 80 I would suggest one of the 90 size mufflers currently on the market. For example Hatori SB 16, the MP2, Funtech 90 size.

Gearing and muffler should be only items that will need to be correct for the YS 80.

David

Matthew · 04-04-2004, 09:59 AM

I thought the fan was threaded differant from the ys and os engine. I may be wrong if so that is good. The gearing change should be easy with what just 11 tooth pinion and the 60 main gear?

DavidH · 04-04-2004, 10:16 AM

Yes I forgot the fan in the Raptor is threaded. I know others that have took an 8mm tap and threaded the fan for 8mm. All they did was run the 8mm tap thru the existing threads. That has worked for the ones I am familar with.

David

Matthew · 04-04-2004, 10:21 AM

Thanks DavidH

If I go the route of the 80 I'll do just that.

04-03-2004, 07:52 PM	#1 (permalink)
Matthew My HF Map location Join Date: Apr 2004	TT 70 help I have a well worn TT70 and was wondering if it is time to rebuild it. I almost have to screw the low end needle all the way out (at least it seems that way) to get it to idle. It has compression but not as much as i think it should. Any help?

04-04-2004, 08:26 AM	#3 (permalink)
WillJames Registered User My HF Map location Join Date: Mar 2004	That is what I was gogin to Say Al. When you do replace it get a 91. That R60 is a fairly heavy (bricklike actually). I was VERY happy when I went from a YS-80 to the 91 C-SPEC in both my Raptors. You are already running 690's on it so your R60 would be a ROCKET with the 91. __________________ William James Crazy wife still trying to kill me.

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04-04-2004, 06:59 AM	#2 (permalink)
Al Magaloff Join Date: Apr 2004	I think you will find that, the parts to rebuild will cost more than a new unit.

04-04-2004, 09:04 AM	#4 (permalink)
Matthew Thread Starter My HF Map location Join Date: Apr 2004	I'd love to drop a 90 in the pup but I don't think I'm ready for the power it holds. It still seems to scream with the 70 in it and were my flying is now I think the 90 would make it to fast for me. Any thoughts?

04-04-2004, 09:10 AM	#5 (permalink)
Al Magaloff Join Date: Apr 2004	I think the YS80 is a great compromise. No gear changes, same blade/boom. And just because your car will do 120mph, doesn't mean you need to go there all the time! I'm not a real fan of the TT70 or TT90. The OS 70 would be a decent choice for replacement too, but I've never seen a motor more plagued, than that thing.

04-04-2004, 09:44 AM	#6 (permalink)
Matthew Thread Starter My HF Map location Join Date: Apr 2004	Your right as fare as the driving goes. I never thought of it that way. I'd need to change the gearing, muffler, and Metal fan with the 80? Any thing else that would have to change?

04-04-2004, 09:54 AM	#7 (permalink)
DavidH My HF Map location Join Date: Mar 2004	Matthew, The YS 80 would need to be geared down in the mid to low 8 range. It will run in the 9 range, but it is basically just burning lots of fuel and not supplying much power. Also in the 9 range you will need to keep a closer eye on the rpms to not overspeed the motor. For the YS 80 I would suggest one of the 90 size mufflers currently on the market. For example Hatori SB 16, the MP2, Funtech 90 size. Gearing and muffler should be only items that will need to be correct for the YS 80. David

04-04-2004, 09:59 AM	#8 (permalink)
Matthew Thread Starter My HF Map location Join Date: Apr 2004	I thought the fan was threaded differant from the ys and os engine. I may be wrong if so that is good. The gearing change should be easy with what just 11 tooth pinion and the 60 main gear?

04-04-2004, 10:16 AM	#9 (permalink)
DavidH My HF Map location Join Date: Mar 2004	Yes I forgot the fan in the Raptor is threaded. I know others that have took an 8mm tap and threaded the fan for 8mm. All they did was run the 8mm tap thru the existing threads. That has worked for the ones I am familar with. David

04-04-2004, 10:21 AM	#10 (permalink)
Matthew Thread Starter My HF Map location Join Date: Apr 2004	Thanks DavidH If I go the route of the 80 I'll do just that.

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