hi i am new to the forum , i have a 2003 Honda rancher 350 . recently rebuilt the top end, it runs but bogs when you give it gas it backfires bad to . i can drive it but it sounds really bad . please help me out if you have any idea what is wrong thanks

 

Seems a lot like dirt in a jet. Clean the carb out. When you remove the fuel tank you disturb sediment which has settled. Very common to have blocked jets or a leaky float needle after taking the tank off. Backfiring can also be a badly fitted exhaust, make sure the joint between head and pipe isn't leaking.

 

 

Possibly you didn't get the valves right the first time. However if the rebuild was because you overheated the engine and seized it, I have known valve seats to loosen and push rods to "go soft" allowing the ***** to recede into the alloy tubes. Worth keeping an eye on the clearances to see if they keep altering.

 

 

 

Valve gides can be replaced, but I have never known one to wear badly on a Honda Quad. Most engine machine shops don't replace guides any more, they ream them out and sleeve them. However I have known guides to come loose in the head, this stops the engine, as they eventually jam a valve slightly open.

"One of the valve rods are damaged too"

If this refers to a pushrod, then you will get the valve clearance on that valve altering.

 

 

 

"Could a damaged rod casuse the valve spring to break"

Don't think so. I've never known a Honda valve spring to break, or pushrods to bend. As I wrote earlier, Honda pushrods normally fail because the steel ***** tend to get hammered further into the aluminium tubes. If they are bent, they could be bent back if you are skilled enough, but it is a lot easier just to get new ones.