andersonj Posted September 12, 2007 Report Share Posted September 12, 2007 (edited) OK, so a few weeks ago I bought what I thought was good condition older Sherco 2.5 as a starter bike to get into trials. Seller explained a local dealer had gone through the bike only a few months earlier and replaced head bearings, swingarm bearings etc. Being mechanically minded but not bike savvy I only gave the bike a superficial inspection. Sale was 'as is'. The really bad....took the muffler and center box off tonight to give a good cleaning and found the header loose....mmmm....closer inspection, only one bolt in the header flange....even worse the other lug in the cylinder head is half broken off.. cr*p. My 'good buy' just turned into a basket case. Not sure what to do at this point. I know a new cylinder is going to be mega $$$$. Maybe I should just cut my losses and sell it a project bike to the next guy. Anyone have even a guess at the cost of a cylinder, gaskets, piston? J. Edited September 12, 2007 by AndersonJ Quote Link to comment Share on other sites More sharing options...
biffsgasgas Posted September 12, 2007 Report Share Posted September 12, 2007 I wouldnt give up so easy on that.... Before you buy a whole new top end bring the bike to a small time local bike shop or even better yet a machine shop. They may be able to remove that bolt in bike using an easy out. If they need you to take the cylinder off its better then replacing the whole thing. If it came down to it you would probably be able to use your old piston anyway. If your in the states give Ryan Youngs shop a call. www.rypusa.com --Biff Quote Link to comment Share on other sites More sharing options...
andersonj Posted September 12, 2007 Author Report Share Posted September 12, 2007 (edited) Bill, Appreciate the reply. If only it was that simple. It's not the bolt thats snapped off but 1/2-3/4 of the boss on the cylinder. Basically a big aluminum chunk is missing. A bolt will thread into it, but I'm not sure how much clamping pressure it would have. i guess in theory the cylinder may be salvageable but removing it, welding up the boss, machining and re-tapping. Are there services in the US that do this type of thing? J. Edited September 12, 2007 by AndersonJ Quote Link to comment Share on other sites More sharing options...
swooshdave Posted September 12, 2007 Report Share Posted September 12, 2007 Bill,Appreciate the reply. If only it was that simple. It's not the bolt thats snapped off but 1/2-3/4 of the boss on the cylinder. Basically a big aluminum chunk is missing. A bolt will thread into it, but I'm not sure how much clamping pressure it would have. i guess in theory the cylinder may be salvageable but removing it, welding up the boss, machining and re-tapping. Are there services in the US that do this type of thing? Joey. Of course. Tons of them. Might help if you post where you are located. Quote Link to comment Share on other sites More sharing options...
copemech Posted September 12, 2007 Report Share Posted September 12, 2007 I am not sure where you are located, but I would think a proper weld repair and re tapping of the thread would fix it. It is a tricky repair, as the weld process can induce distortion in the Nicasil coated bore of the cylinder. I have not done it! But there are specialists about ! A repair should be at least half the cost of a new one, which is probably around $500 US i would estimate. However if the job has done in the bore, requireing a re-chrome, the cost would be near a new one! Worth a repair attempt though! Quote Link to comment Share on other sites More sharing options...
andersonj Posted September 12, 2007 Author Report Share Posted September 12, 2007 (edited) I'm in Kentucky, USA. J. Edited September 12, 2007 by AndersonJ Quote Link to comment Share on other sites More sharing options...
copemech Posted September 12, 2007 Report Share Posted September 12, 2007 My first thought would be B&J racing or you can call RYP and ask if Ryan knows someone local that can do it! Or if there have been problems in performing that specific repair! 800-607-8742 Maybe Al B. can chime in ? Or even do it for you as he has the stuff! Quote Link to comment Share on other sites More sharing options...
alan bechard Posted September 12, 2007 Report Share Posted September 12, 2007 Never done a Sherco, but have had to do a couple cylinders. Should not be that big a deal. I would give Ryan a shout first, and inspect the thing to make sure it was in good shape before fooling with it, but if you want to I would be happy to look at it with you. Let me know. Al B Quote Link to comment Share on other sites More sharing options...
andersonj Posted September 12, 2007 Author Report Share Posted September 12, 2007 Had a good chat with RYP this AM about my cylinder problem. Looks like it will be salvageable with some welding and machining. Going to pop off the cylinder and bring it to the local event in Columbus IN on Saturday for the RYP people to look at in person. Also working on finding a local source to do the work. Feeling a whole lot better that when I discovered the issue last night. Thanks to all. J. Quote Link to comment Share on other sites More sharing options...
copemech Posted September 12, 2007 Report Share Posted September 12, 2007 Good deal, keep us posted! Quote Link to comment Share on other sites More sharing options...
andersonj Posted September 14, 2007 Author Report Share Posted September 14, 2007 (edited) Well, got the cylinder off tonight. Not that difficult after I took the electronics out and slid the radiator up out the way. Bore looks good, no scrapes or scratches. Honing marks are gone from the active stroke area however Piston is 1st bore 'A'. There was a fair amount of carbon build up on the piston (1/32"?). Got that all off and cleaned up. Also cleaned up the transfer ports, exhaust ports and the head. There was some dark brown discoloration below the two rings on the sides of the bore in line with the main transfer ports. Does this mean I am getting blow-by around the rings? Is this normal? Wondering if I should put in a new top end since its apart, that decision can wait though. My main area of concern is the cylinder studs. 3 of the 4 show some corrosion, particulary the front ones. I would say it is 'moderate surface rust'. I'm guessing because the water passage is at the front and at some time a small amount of water leaked to the stud area. I put "PB Blaster" penetrating spray on the threads before removing the nuts at the base of the cylinder and they came off pretty easily. Now my concern is when I replace the cylinder and torque down the nuts that I shear the studs. Sent some pictures to a number of cylinder repair places around the country. Only got one estimate back "probably less than $200". Still looking for a local, good quality (and cheaper) alternative. J. Edited September 14, 2007 by AndersonJ Quote Link to comment Share on other sites More sharing options...
biffsgasgas Posted September 14, 2007 Report Share Posted September 14, 2007 ooo thats a good one. The base gasket studs should thread out using a pipe wrench. I have replaced these before on other trials bikes. Mainly gasgas but they are pretty much the same. Industrial supply companies may stock the thread pitch you have. Be ware of striping out the threads in the block that hasle may not be worth replacing the old ones. A lot of buddies up here in detroit love drag racing and some work for nhra teams. I know a couple of teams who dont flinch throwing a rod thru a block on a weekend. They just take it back weld it up and resleve the thing Look for a drag shop in your area. They will probably know somebody who can weld that up. --Biff Quote Link to comment Share on other sites More sharing options...
copemech Posted September 14, 2007 Report Share Posted September 14, 2007 Based totally on your report, which i cannot see everything, I would stick with the original plan, let the RYP guys look at the bore and proceed as neccessary. Looks like a good fixer on the break though, and Al has already offered his services. He is as cheap as it gets I would think. Weather or not to go with a new ring or hone it and fit a B piston is TBD i would think! If the studs have plenty of metal left, clean them up, and leave them alone, coat with corrosive prentative grease on asembly! There are many different ways to skin that cat! M2C Quote Link to comment Share on other sites More sharing options...
alan bechard Posted September 14, 2007 Report Share Posted September 14, 2007 Let Ryan, Brad and the crew take a first hand look see. Lot easier to get a good feel for it if it is in your hands. They won't steer you wrong. Jimmy Z will probably be around as well, and he is great. Where in KY are you? Quote Link to comment Share on other sites More sharing options...
andersonj Posted September 14, 2007 Author Report Share Posted September 14, 2007 Hopefully I can get some first hand advice on Saturday at the Columbus IN event. I work in Erlanger N.Ky, and live in the Milford/Loveland, NE Cinci. J. Quote Link to comment Share on other sites More sharing options...
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