Troy-Bilt 4 cycle backpack leaf blower has no high rpm

[StarTech]

OK so an MTD engine is a AC4. Now if I need parts, like rings, I should ask MTD for part numbers?

Troy-bilt machines are built by MTD.

You won't find rings separately as MTD only sells the shortblock pn 753-08026. Again because oiling damage. Even with buying from my MTD distributor it still costs me nearly $100. And the time add some of my labor (I mean less half my time) it still cost the customer as much as a new machine so I just tell them go by another blower.

BTW it would be nice if we could get just the PNC but MTD won't sell the parts that way.

 

[Richie F]

Troy-bilt machines are built by MTD.

You won't find rings separately as MTD only sells the shortblock pn 753-08026. Again because oiling damage. Even with buying from my MTD distributor it still costs me nearly $100. And the time add some of my labor (I mean less half my time) it still cost the customer as much as a new machine so I just tell them go by another blower.

BTW it would be nice if we could get just the PNC but MTD won't sell the parts that way.

I just got off the phone with Troy Bilt a.k.a. MTD and found out the same thing.
You talk of an oiling problem. Can you explain that more?

 

[StarTech]

Yes, the oil problem is caused by OEM using a dipper system and when you only have 2-3 tablespoons full oil the oil dipper is not always dipping into the oil especially when these are tilled a fair amount during operations. Other 4 cycle hand held engines uses a pressurize like system like the Matika and Shindaiwa engines. And of course there is the Stihl 4-Mix setup that just use a 2 cycle fuel mix to lube the engine. None of these three brands I ever seen oil failure problems.

Any who, I Got go to work in the shop as is Monday morning here.

 

[Richie F]

Yes, the oil problem is caused by OEM using a dipper system and when you only have 2-3 tablespoons full oil the oil dipper is not always dipping into the oil especially when these are tilled a fair amount during operations. Other 4 cycle hand held engines uses a pressurize like system like the Matika and Shindaiwa engines. And of course there is the Stihl 4-Mix setup that just use a 2 cycle fuel mix to lube the engine. None of these three brands I ever seen oil failure problems.

Any who, I Got go to work in the shop as is Monday morning here.

So a replacement short block won't solve the problem then?

 

[dougand3]

So a replacement short block won't solve the problem then?

It may run factory new if carb & fuel lines are good....for a while. Then you use it with an engine tilt and oil slinger/dipper doesn't splash oil. P, R & C are oil starved and start scoring - compression drops. I'm just a hobby mechanic but I've learned to steer clear of tiny MTD 4 strokes. Neighbors try to give me a non-runner - I say "Nope". Like Star says - if you want a 4 stroke in a tiny multiple positions engine, get pressurized lube. Stihl has the 4 mix but I don't see the advantage of 2 stroke fuel in a 4 stroke with the added weight & complexity of valves & oil sump. I've had good luck with Stihl & Echo 2 stroke - quality is there. I'v got 4 of them and they just run when carb is clean. Get one with carb trouble for free-$10.

 

[StarTech]

Doug, if you ever had you hand on the Stihl FS90, or FS130 (4180 engine) you know they are just about the same weight as the 2 cycles. Now I hated the old Ryobi 725R I had and it last exactly one year before it failed; plus weight a lot more.

 

[dougand3]

If weight not increased - great. I have 2x FS55 and run them hard. They just scream.

 

[Richie F]

It may run factory new if carb & fuel lines are good....for a while. Then you use it with an engine tilt and oil slinger/dipper doesn't splash oil. P, R & C are oil starved and start scoring - compression drops. I'm just a hobby mechanic but I've learned to steer clear of tiny MTD 4 strokes. Neighbors try to give me a non-runner - I say "Nope". Like Star says - if you want a 4 stroke in a tiny multiple positions engine, get pressurized lube. Stihl has the 4 mix but I don't see the advantage of 2 stroke fuel in a 4 stroke with the added weight & complexity of valves & oil sump. I've had good luck with Stihl & Echo 2 stroke - quality is there. I'v got 4 of them and they just run when carb is clean. Get one with carb trouble for free-$10.

Thanks for your reply.
This does run to a point and since the answer is a piston/ring/cylinder problem I'm going to first use an additive like Lucas or STP in the oil and see if the engine "starts" to come alive.
This is just for my curiosity.
I'll take the engine apart later to get measurements off of the rings and see if I can retrofit something or maybe not.
I did find a seller on Ebay that sells a short block for $109 w/free shipping also.

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[StarTech]

If weight not increased - great. I have 2x FS55 and run them hard. They just scream.

Now the FS55 (34mm, 27.2cc, 0.9 bhp) is a light weight unit and the FS90R (38mm, 28.4cc, 1.3 bhp) is a commercial grade unit (beefier components) that only is 1.3 heavier IE 10.8 vs 12.1 lbs. plus the FS55 only a 330cc fuel tank vs the FS90 530cc fuel tank, so course it weigh a little more.

 

[Richie F]

Being this blower is a splash system are there ways to prevent the problem from happening?
This is a back pack blower and I would think not much tilting goes on compared to a trimmer.