Author Topic: need to rebuild top end  (Read 3296 times)


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need to rebuild top end
« on: March 15, 2012, 02:47:09 AM »
hello everyone !!
I'm new to the forum i purchased a 85 fl350 a few years ago would only take it out once maybe twice a year since purchased and the last time i took it out i was told i blew the top end (by running it too lean) I'm tired of seeing it just sitting there i would like to know if anyone knows of a shop i can take the top end to get rebuilt??
and would i have to redo the bottom end as well ? ?
thank you in advance.



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Re: need to rebuild top end
« Reply #1 on: March 15, 2012, 05:11:05 AM »
Leaking crank seals are a very likely culprit. The seals harden with age and leak. It is a very common problem starting 5 years ago or more just from the age of the machines. The seals leak and let air in which leans out the engine and the top end fails.

Here are tips on considerations that need to be made for the FL350R Rebuild:

If you can remove the top end and ship it out, we do many of them:

You can replace the crank seals without splitting the cases apart by driving screws in them and pulling from the outside. You do need to pull the clutch, counter balancer drive gear, flywheel and stator to get to them:

Factory 45

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Re: need to rebuild top end
« Reply #2 on: April 06, 2012, 04:35:26 AM »
Hey Charlie :) Im not sure how wrench savy you are with a toy or a car but these engines can be easily damaged if not dismantled properly. Could end up costing more in the long run. My suggestion...if you are not 100% confident in taking this engine apart is to LEAVE THE ENGINE COMPLETE and remove it. There are very few mechanics that have a knack for these engines...and what works to replace the parts within. Not to say that you couldnt get a rebuild locally...but for it to last and make it worth the money BOX IT and ship it to someone that has done FL engines. By leaving the engine complete you will be giving the builder a chance to leak test prior to teardown (a step very important to a 2 cycle inspection)

Livewire is correct in saying that crankshaft seals are a good source for engine AIR LEAKS...but this is something that may start you down the road of a total rebuild QUICKLY. It is a 1985 Engine and most likely has had some type of top end repair over the years BUT if the crank is ORIGINAL and the Main Bearings or Countershaft Bearings are worn...then you may be out of your leauge. THIS IS NOT A GOOD POINT TO START CUTTING CORNERS. Somebody with EXPERIENCE needs to do the stuff in order to not ruin good parts.

You could do some in the garage things to check and see if you may have worn parts BEYOND the top end. WITHOUT TEARING THE ENGINE see if you need to remove it and send it out for rebuild. I will give you some things to check...but only if you PROMISE and SWEAR that you have a METRIC socket and wrench set and are capable of going step by step...and dont jump the gun on me :)

I just so happen to have a complete 350 @ the shop and a totally torn down engine to show you some pics.

Is there a chance that you just tried to ride this machine...without draining and changing the fuel (pump gas) after it sat for a period? Then you had a problem after a short ride?