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Ok I had to replace a short block on a duraforce due to a rusty connecting rod bearing from being stored outside, anyway on another site someone is claiming that some dura-force's use a bushing instead of needle bearings. The one I had apart did have a needle bearing no doubt about that. Seems that a needle bearing is a much better idea then a bushing. I cannot believe that some dura-force would have needle bearings and some would not. Can anyone confirm this?

lewb said:

Ok I had to replace a short block on a duraforce due to a rusty connecting rod bearing from being stored outside, anyway on another site someone is claiming that some dura-force's use a bushing instead of needle bearings. The one I had apart did have a needle bearing no doubt about that. Seems that a needle bearing is a much better idea then a bushing. I cannot believe that some dura-force would have needle bearings and some would not. Can anyone confirm this?

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Not being very familiar with a 6.5 dura-force engine. I am going the take a guess a 6.5 Dura-force engine is a 2 cycle engine. I do believe they engineer the rod bearings for lubrication reasons in the 2 cycle engines different then the 4 cycle engines. I have found 2 cycle engines have needle bearings and the 4 cycle engines use rod inserts.

yes its a 2-stroke, unfortunately I cannot find a parts break down, it is only listed as a complete short block from what I have found. I did find a service manual it appears to be needle bearing like I suspected.

lewb said:

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yes its a 2-stroke, unfortunately I cannot find a parts break down, it is only listed as a complete short block from what I have found. I did find a service manual it appears to be needle bearing like I suspected.

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I think there's needle bearings on the big end and a bushing on the small end. https://lookup3.toro.com/partdex/index.cfm?xCaller=Toro&lang=us_en

Streamlight said:

I think there's needle bearings on the big end and a bushing on the small end. https://lookup3.toro.com/partdex/index.cfm?xCaller=Toro&lang=us_en

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needle bearings big end (crankshaft bearings) bushings small end (wristpin bushings) could well be. I have found that most 2-stroke engines have needle bearings on both ends. I am just talking from my own experiences through the years of repairs. There may well be out there 2-stroke engines with bushings but nothing I ever came across. I also find that 2 stroke have what they call floating wristpins, loose in the piston and some 4 stroke engines have press in wrist-pins but not all.

they have a roller bearing on the wrist pin fast forward to 6 minute mark of this video.

https://www.youtube.com/watch?v=3_uPX5wpDpk

683911 BEARING-NEEDLE

The video they show is for a "V" series engine, it might have the same needle bearing, however I went and looked at the duraforce parts motor I have and got the part number off of the wrist pin needle bearing, which is Torrington B-88. Ebay sells those for around five dollars.

I did find of toro site with all the drawings and everyone of the duraforce shows a needle bearing on the connecting rod and wrist pin when you pull up the connecting rod description.

lewb said:

I did find of toro site with all the drawings and everyone of the duraforce shows a needle bearing on the connecting rod and wrist pin when you pull up the connecting rod description.

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I think I was trying to say that 2 stroke engines use needle bearings, but about the time I would say 2 stroke engines never used bushings someone would prove me wrong. Through the years there has been a lot of different engine designs and I sure don't know what is out there.