I just had the engine rebuilt, bottom end and top. I have new plugs in its getting gas and air, the timing is right on, and it turns over just like it should. I had it in the dealership and they couldn't figure it out and started acting rude so I took it from them. The carb was rebuilt pretty much also ..new diaphram, needle and seat, float kit.... I'm lost ive went through the wiring and it all looks good tight connections grounds are good. It will backfire if I spray starting fluid down the carb but thats about it. Ive went to a hotter plug the stock is DR8EA and I went to a DR7EA but still no luck. Anyone have any suggestions on what I should check??[img]i/expressions/face-icon-small-confused.gif[/img]

 

3 little things to check before getting worried air, make sure its able to breathe, 2 make sure you have gas going through the carb, and 3 check for spark, a nice blue consistent spark . With all three of these you should be able to get a little something out of it. If you have all 3 and still nothing shut the gas off from your tank and see if you can keep it running with the fluid. maybe you are getting to much gas. let us know.

 

You need to double check your cam timing. Do you know how to do this? if not we can help.

also, make sure your battery is charged, if it is low, it may still crank the engine , but won't start.






bigger.

 

Just a long shot here but if everything else is OK as sugested so far then you may have an Air intake leak between the carb and the head. The stock manifold / ported manifold has two O-rings that make the seal. Maybe one or both slipped out of their grove a little bit when you reinstalled the manifold. Your symptoms sound a lot like an intake air leak. If your valve gaps are WAY off you'll not be able to get it started either. If there way to tight then you won't be able to maintain compression. To way to loose and you won't get fuel / air. Theses are the extreems but might as well check. if the rest doesn't produce any results

 

hehehe make sure the intake cam and exhaust cams are not swapped, your symptoms sound all too fimiliar......lol

ya never know, sometimes you overlook the easiest things, or as bigger put it you can't see the forest through the trees...

 

Im getting air, fuel, and fire I checked both plugs and coils seperatly to make sure. The timing was set by the dealer. I will have to check for intake leaks that is possible i suppose.
How do you tell if the cams are swapped? I doubt they are but how do you tell just in case. And if they were swapped wouldn't it be back firing?

thank you guys for your help i will look for intake leaks today............

 

I checked today for any intake leaks with no luck or should I say no leaks.... Both of the rubber O-rings are in the grooves. When I take the airbox tube off of the carb and try to start it if I put my hand over the carb letting small amounts of air in it acts like it wants to start but still won't go all the way and run. My battery is brand new and fully charged I just got it about 2 weeks ago. I don't think that its getting to much gas because the plugs are still dry. The valve gaps were set according to the service manual when I got the engine rebuilt... however I have a dome piston in there now its a 11.5:1 RWR so should the gaps be different???

 

You should put you palm of your hande over the carb inlet while cranking the engine over, actually blocking air flow, this will force the carb to suck out large amounts of fuel from the bowl(old choking technique). After a few cranks your engine will either start, or atleast your plugs will be soaked with gas.

The gaps won't be different no matter what piston you have in their. If it still won't start after choking the carb, take off the valve cover. lock your crank at TDC using a crank bolt( you can make one if you don't have one, by using one of the bolts that hold on your factory rear disk protector, you will need to cone the end of the bolt) Their is a 12mm allen head bolt under your side case(clutch side) after you take it out you will be staring at the crank, if the piston is at TDC you will see a "slot" on the crank through this hole(you will need to use a flash light). After you have the piston at TDC your cams lobes should be pointing away from eachother. the timing marks on you cam sprockets should in alighnment.




Bigger.





bigger

 

Do exactly what bigger says. If the timming is not OK correct it and then double check the gaps between the cam and the valve shims. Check all 4 of them and record your findings. I think stock was between .004 and .006. Since your valve cover is off check the gaps even if the timming is OK.

 

and the decompression lever is on the exhaust cam, not the inkake, lol