Premium members don't see ads. Click here to upgrade.

Wt668 vs 990

suicyderider

Member
Messages
22
Location
West Virginia
How much of a running difference could one expect by swapping from a 668 to 990 . I couldnt get truck running with 990 but 668 fired up quickly. I think i may know how to get the 990 ging though but if its not really noticeable i wont even try. I have a 29cc with a crazy stu intake. Is it worth it?51783
 

Attachments

Phill2

Well-Known Member
Messages
519
Location
Yeppoon QLD Aus
If you read the specs a990 is just a 668 with no choke.
I found you can start it easier if you open the LSN half a turn then readjust when you get it going.
The other way is to spray starter fluid in through the air filter.
I couldn't see any difference so I went back to the 668.
If you're running a 32cc go to an 1107.
 

Bill Mossor

Well-Known Member
Messages
74
I wondered the same thing, so I tested them. Out bashing I could not tell the difference but on our 500' track, the 990 was 1 to 2 seconds faster per lap, then the 668 . If you are just bashing stay with the 668 but if you are racing go with the 990. They are different carbs & require different carb settings. The 668 is 1 1/4 on low & 1 1/2 on high but the 990 is 1 1/8 on low & 1 5/8 on high.
 

Phill2

Well-Known Member
Messages
519
Location
Yeppoon QLD Aus
I wondered the same thing, so I tested them. Out bashing I could not tell the difference but on our 500' track, the 990 was 1 to 2 seconds faster per lap, then the 668. If you are just bashing stay with the 668 but if you are racing go with the 990. They are different carbs & require different carb settings. The 668 is 1 1/4 on low & 1 1/2 on high but the 990 is 1 1/8 on low & 1 5/8 on high.
On a G290 I had to run the low at less than 1 turn for it to idle.
2 seconds is a big gap on such a short track.
Must be a very technical circuit?
 

Bill Mossor

Well-Known Member
Messages
74
On a G290 I had to run the low at less than 1 turn for it to idle.
2 seconds is a big gap on such a short track.
Must be a very technical circuit?
I tested with a HPI 5B, with a OBR 29cc engine, & ran with stock needle settings, ran & idled fine. On average I picked up at least 1 second but less then 2 seconds with the 990 over the 668.
 

suicyderider

Member
Messages
22
Location
West Virginia
Great to know, well when the truck arrived it had the 990 installed and I spent hours tryin and tryin to get it started but could not.. spent weekend drying it out and then tried again , nothing. I decided to swap carbs and within a handful of pulls and with some assistance from Bill Mossor and the videos on setup I had it running and semi tuned with 668. After learning the settings and some other tips n tricks I decided to try the 990 again.. low and behold I had her running within 10 pulls and now she starts within a handful of attempts. I haven't ran her hard yet with the 990 but if shell keep firing ill leave it on and see how she goes. Hopefully I can make it up to the track I may just have to show up tomorrow even though ill have my hands full with babies.
 

Bill Mossor

Well-Known Member
Messages
74
View attachment 51830wishin i was at the SWPARC track but at least im out
Only three of us were racing 2wd Baja's today. Got my but kicked on my own track by this one guy, past couple of years I only raced our 4x4's & it took some getting used to the 2wd again, my race set up was off, had wrong tires, & whatever other excuse you can think of for coming in 2nd almost every race today, but I did improved a lot by end of day. Had a bunch of fun. There should be some more people next Sunday.
 

Bill Mossor

Well-Known Member
Messages
74
View attachment 51830wishin i was at the SWPARC track but at least im out
FYI the owner of SWPARC dose not want us posting about 1/5 scale racing on his page anymore because he fells it excludes people. so I will be posting on
https://www.facebook.com/pg/ShowMeYourHobbies/posts/?ref=page_internal

the days our track will be open.
As for now will be racing next two Sundays 6/16 & 6/23 gates will be open by 12noon.
Then closed for two Sundays 6/30 & 7/7
reopen Sunday 7/14
Use GPS coordinates 40.250022 -79.751844 to get here address is 200 Carnegie Rd. Irwin Pa. 15642 look for green mail box with 200 on it.
 

suicyderider

Member
Messages
22
Location
West Virginia
FYI the owner of SWPARC dose not want us posting about 1/5 scale racing on his page anymore because he fells it excludes people. so I will be posting on
https://www.facebook.com/pg/ShowMeYourHobbies/posts/?ref=page_internal

the days our track will be open.
As for now will be racing next two Sundays 6/16 & 6/23 gates will be open by 12noon.
Then closed for two Sundays 6/30 & 7/7
reopen Sunday 7/14
Use GPS coordinates 40.250022 -79.751844 to get here address is 200 Carnegie Rd. Irwin Pa. 15642 look for green mail box with 200 on it.
and it was bc the XMAXX guy wants to run .. you could get around it by saying 1/5th scale cars welcome lol xmaxx is only 1/6 so technically youre allowing everyone still lol
 

Bill Mossor

Well-Known Member
Messages
74
and it was bc the XMAXX guy wants to run .. you could get around it by saying 1/5th scale cars welcome lol xmaxx is only 1/6 so technically youre allowing everyone still lol
We will be racing here, next two Sundays, then closed for two weeks, then when we reopen on July 14, I think we going to start our own facebook group. I think we are going to call our place & FB page, The RC Playground of Pa.. I will let you know when we decide.
 
Premium members don't see ads. Click here to upgrade.
Top