87 Spree will not rev up or cuts out

[snowworks]

Hey all, Have not posted in some time but have been lurking for awhile. Just picked up this 87 Spree this summer. Not running of corse. Sitting for years. All my stuff is old and broke. History,, 3000 miles No crank. Found the ignition switch bad replace with new one and it cranks good. Cleaned the tank and carb. Bystarter missing the needel. Replaced with new, works good. Now the spree will start and idle good!!. What it is doing is when you full throttle it revs up and goes about 50 feet. 10 to 15 mph and it fall on its face. I let off and it idles good. I hit the throttle again and it revs alittle and fall down again. Now if I nurse the throttle I can get it to run OK between 10 and 15 mph, any faster it bogs out. On the stand I can get it to rev up some times?? I have rulled out fuel. Delivery is good. I pulled the hose off and used a mityvac and the hose flows great to the carb. I have rode it also with the mityvac connected and no difference. I have had the carb off a few times all clean and passages open. Took the exhaust off and made sure the port is clean. The manual says check timming and I did, the F mark is lined up with the pointer off idle. OK. I pulled the connections off at the Ignition coil, CDI and regulator. All look good. Compression is at 105 psi. I noticed in the FAQ ignition coil suspect. I might have another one. I will try that. I think the CDI is different 84-85, and 86-87? Correct?? and I do not think I have one. Ridding it some times I think it has a slight miss?? If I let off the throttle it runs OK. ANY suggestions?? My next thought is to try a different coil maybe check the reed?? Brian in MI..

[patthesoundguy]

the exhaust could be clogged up check the wheel end of the pipe insects like to nest there. if the hose to the air box is not connected it will do that too. you can still have a fuel delivery issue. if the carb fuel inlet is clogged up with crud it may not be feeding the bowl properly. I had that issue on my golf cart, took forever to figure out. also check the tank screen they can get partially clogged and will run strange under a full tank. checking the reeds is not a bad idea but unlikely the issue. 105 compression is kinda low. the coil and cdi can also cause those kinds of issues as well as a bad plug. check all of the wiring on the frame there is a large rubber jacket down by the oil pump on the carb side of the motor that houses a whole bunch of bullet connectors. check all of those. my Spree Dio ran like that when I had bad ground for the ignition, it would idle great and you could rev it up but when you drove it under load it was crap at about the same speed you have issues. Same thing, you could baby it and get faster but not really. you are totally doing your homework, you will get this sorted out.